Any pointers for tuning a Buddy 50 with a 70 cc kit?

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blaupunk
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Any pointers for tuning a Buddy 50 with a 70 cc kit?

Post by blaupunk »

My wife wanted more acceleration and a little higher top end in her Buddy 50, so she picked out a nicely prepared kit, which we installed ourselves. (I do a lot of work on cars, but this is my first foray into 2-stroke land)

Everything is running well enough, but for the life of me, I cannot seem to get it tuned where it doesn't bog down.

Identical kit:
http://www.scooterworks.com/performance ... fQzcDPD_MI

70cc Head and Piston
Prima Exhaust
Performance Clutch Spring (1000 rpm)
Performance Rollers (can't find the box right now to get the weight)
80, 90, 95 Main Jets

With Prima Pipe:
It would accelerate from stop to about 5-10mph, bog for about 10 seconds, then take of like a shot once it hit about 13mph. I litteraly have to hold on tight... it's awesome!

I've since read that a lot of people seemed to have trouble tuning with the Prima pipe, so i put the stock one back on.

With stock pipe:
Seams to accelerate decently enough (but not much better than stock), but won't go above 30-35mph.

Both setups have been tried with pilot jets from 35-48 (stock is 40) and main jets from 75-95(stock is 75). I now have a very healthy collection of jets. ; )

Crud! I just saw in that link that it says that it may require a pod filter and/or intake mods. I haven't done that... :fp:

Does anyone have any advice for tuning this kit correctly? And/or the best way to tune the intake as noted in that link?
lovemysan
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Post by lovemysan »

Are you adjusting the idle mixture screw? Not the idle speed screw.
lovemysan
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Post by lovemysan »

Also where are you located? My suggestion would be: Install the prima pipe, Install the 95 jet, adjust the idle mix screw to achieve highest possible idle. I bought every jet 80-110 for mine. Your carb is a keihin pb16 btw.
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Post by Roofaloof »

While I've yet only worked on a 150 CC buddy engine, my guess is that you do need to do something to open up your intake side to realize full performance gains.

The stock intake will act as a restrictor now that you've got almost 50 percent more air to move through the engine.

You can either get a pod filter or just drill some holes in your stock air box to open it up. My guess is that doing some work on the intake side will smooth out your performance.
lovemysan
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Post by lovemysan »

I've seen several kitted 2t's around town running the stock airbox. I removed the snorkel on mine and drilled 6 1/4" holes. It took about 6 hours to get it tuned.
blaupunk
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Post by blaupunk »

lovemysan wrote:Are you adjusting the idle mixture screw? Not the idle speed screw.
Thank you so much everyone for the help!

For each jet combination I would try to find an optimal fuel adjustment using the fuel adjustment screw. (The one with the big black knob.)
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Post by blaupunk »

Roofaloof wrote:While I've yet only worked on a 150 CC buddy engine, my guess is that you do need to do something to open up your intake side to realize full performance gains.

The stock intake will act as a restrictor now that you've got almost 50 percent more air to move through the engine.

You can either get a pod filter or just drill some holes in your stock air box to open it up. My guess is that doing some work on the intake side will smooth out your performance.
Nice... like the classic vw Corrado Swiss cheese mod. :)

For testing purposes, do you think I could take the box off and fashion a filter out of cheese cloth (fine mesh cloth used for staining foods) or something? Or does it need to be somewhat restricted by a filter? I'm in Fairfield,ct and none of the close by cycle shops carry anything for this scoot, so waiting a week at a time for parts is taking forever.
blaupunk
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Post by blaupunk »

lovemysan wrote:I've seen several kitted 2t's around town running the stock airbox. I removed the snorkel on mine and drilled 6 1/4" holes. It took about 6 hours to get it tuned.
What part of the box did you drill the holes? I would assume just on the outward face right? Probably a silly question, but just want to be sure before permanent mods ;)

And thanks again for all the advice
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Post by lovemysan »

blaupunk wrote:
lovemysan wrote:Are you adjusting the idle mixture screw? Not the idle speed screw.
Thank you so much everyone for the help!

For each jet combination I would try to find an optimal fuel adjustment using the fuel adjustment screw. (The one with the big black knob.)

This is your problem the black screw is the idle speed screw. The idle mix is the brass slotted screw I believe directly left and slightly below the idle speed screw. It sits flush with the carb body at a 45 degree angle. Adjust it only with a hot motor,operating temp, as the auto choke will interfere otherwise. Adjust for fastest idle and a smooth throttle response with no bog. Then reset the idle speed screw last. The stock carb is technically too small. An undersized carb can cause hot running and seizing. However if its ridden carefully and not run too hard its okay. Holding it at wot for long periods is what kills them. If it starts to get doggy or you notice that it taking more time to "get into the powerband or on the pipe" it's HOT. I nearly seized mine running without the airbox. It only took 4 minutes to get that hot.
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Post by lovemysan »

blaupunk wrote:
Roofaloof wrote:While I've yet only worked on a 150 CC buddy engine, my guess is that you do need to do something to open up your intake side to realize full performance gains.

The stock intake will act as a restrictor now that you've got almost 50 percent more air to move through the engine.

You can either get a pod filter or just drill some holes in your stock air box to open it up. My guess is that doing some work on the intake side will smooth out your performance.
Nice... like the classic vw Corrado Swiss cheese mod. :)

For testing purposes, do you think I could take the box off and fashion a filter out of cheese cloth (fine mesh cloth used for staining foods) or something? Or does it need to be somewhat restricted by a filter? I'm in Fairfield,ct and none of the close by cycle shops carry anything for this scoot, so waiting a week at a time for parts is taking forever.
.

IMO you need more carb. 17.5 or 19mm would be best. With no airbox your mileage with be in 50-60mpg range. I think a 38mm unifilter throat will slip over the carb mouth if that's the direction you want to go most powers ports places all them. Try the tuning tips above before removing the airbox. Loosening the filter cover screws has the same effect as drilling holes btw. Loosen them for 1/32" play in the cover. Also the Vespa 50s have a summer airbox hole and a winter plug as the mixture leans in cold weather. Black electric tape will last all winter covering he airbox holes. On idle mix setting 1-2 turns out is normal if you exceed 2 turns you need a larger pilot jet. I think the stock pilot will be okay though.
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Post by Stitch »

blaupunk wrote:
Roofaloof wrote:While I've yet only worked on a 150 CC buddy engine, my guess is that you do need to do something to open up your intake side to realize full performance gains.

The stock intake will act as a restrictor now that you've got almost 50 percent more air to move through the engine.

You can either get a pod filter or just drill some holes in your stock air box to open it up. My guess is that doing some work on the intake side will smooth out your performance.
Nice... like the classic vw Corrado Swiss cheese mod. :)

For testing purposes, do you think I could take the box off and fashion a filter out of cheese cloth (fine mesh cloth used for staining foods) or something? Or does it need to be somewhat restricted by a filter? I'm in Fairfield,ct and none of the close by cycle shops carry anything for this scoot, so waiting a week at a time for parts is taking forever.
Should be ok with a cheese cloth air filter. Just keep it clean and use rubber bands or something so it can't slip off
"Stella" is Latin for "use threadlocker on all fasteners"
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Post by blaupunk »

lovemysan wrote:
blaupunk wrote:
Roofaloof wrote:While I've yet only worked on a 150 CC buddy engine, my guess is that you do need to do something to open up your intake side to realize full performance gains.

The stock intake will act as a restrictor now that you've got almost 50 percent more air to move through the engine.

You can either get a pod filter or just drill some holes in your stock air box to open it up. My guess is that doing some work on the intake side will smooth out your performance.
Nice... like the classic vw Corrado Swiss cheese mod. :)

For testing purposes, do you think I could take the box off and fashion a filter out of cheese cloth (fine mesh cloth used for staining foods) or something? Or does it need to be somewhat restricted by a filter? I'm in Fairfield,ct and none of the close by cycle shops carry anything for this scoot, so waiting a week at a time for parts is taking forever.
.

IMO you need more carb. 17.5 or 19mm would be best. With no airbox your mileage with be in 50-60mpg range. I think a 38mm unifilter throat will slip over the carb mouth if that's the direction you want to go most powers ports places all them. Try the tuning tips above before removing the airbox. Loosening the filter cover screws has the same effect as drilling holes btw. Loosen them for 1/32" play in the cover. Also the Vespa 50s have a summer airbox hole and a winter plug as the mixture leans in cold weather. Black electric tape will last all winter covering he airbox holes. On idle mix setting 1-2 turns out is normal if you exceed 2 turns you need a larger pilot jet. I think the stock pilot will be okay though.
Thanks! I'll get out there in a bit and check it out. Are you running the stock carb?
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Post by lovemysan »

Ive only worked on stock carbs. But i sold my roughhouse and buddy 50 last fall. No cash lol.
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Post by blaupunk »

lovemysan wrote:Ive only worked on stock carbs. But i sold my roughhouse and buddy 50 last fall. No cash lol.
I inspected the carb. Next to the black knob is another brass fitting, but it has no head and the top is painted red. Is this the proper adjustment screw... that they possibly tamper proofed? If so, how do I adjust it... cut a slot with a Drexel or just latch on with a vice grip maybe?
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Post by lovemysan »

blaupunk wrote:
lovemysan wrote:Ive only worked on stock carbs. But i sold my roughhouse and buddy 50 last fall. No cash lol.
I inspected the carb. Next to the black knob is another brass fitting, but it has no head and the top is painted red. Is this the proper adjustment screw... that they possibly tamper proofed? If so, how do I adjust it... cut a slot with a Drexel or just latch on with a vice grip maybe?
Yes I used a sharp oring pick and turned mine out. And yes cut a slot with a Dremel.
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Post by blaupunk »

lovemysan wrote:
blaupunk wrote:
lovemysan wrote:Ive only worked on stock carbs. But i sold my roughhouse and buddy 50 last fall. No cash lol.
I inspected the carb. Next to the black knob is another brass fitting, but it has no head and the top is painted red. Is this the proper adjustment screw... that they possibly tamper proofed? If so, how do I adjust it... cut a slot with a Drexel or just latch on with a vice grip maybe?
Yes I used a sharp oring pick and turned mine out. And yes cut a slot with a Dremel.
I owe you a beer! Prima is back on. 95 main jet in. Loosened the filter box cover... takes off like a bat out a hell all the way up the rev range!

I'm probably going to get some >95 jets to make sure it's dialled in. Do you think I will still need to mess with the fuel mix screw or leave it be?
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Post by lovemysan »

Just be careful you don't want to seize it. How does it run with the filter cover tight? You should be able to dial it in with the mix screw and the cover on tight.
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Post by basilfawlty »

This thread is great. I've gone down a similar road with my buddy 50 and it has taken ages to get things running smoothly. I ended up adding a 19mm malossi carb (after burning out my first 70cc kit) and had a heck of a time getting things dialed in.

I still can't get my performance pipe to work. I get about half the power when the pipe is on vs. stock.
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Post by blaupunk »

lovemysan wrote:Just be careful you don't want to seize it. How does it run with the filter cover tight? You should be able to dial it in with the mix screw and the cover on tight.
With the filter cover tight it bogs down too much to get into it's power band and runs super rich.

Seams like the intake is essentially acting like a resricter plate, so I was planning on drilling 1 hole at a time only until it runs proper. Does that make sense, so that it keeps it restricted to only the volume of air it needs, but can't pull too much air and end up lean and hot?
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Post by blaupunk »

basilfawlty wrote:This thread is great. I've gone down a similar road with my buddy 50 and it has taken ages to get things running smoothly. I ended up adding a 19mm malossi carb (after burning out my first 70cc kit) and had a heck of a time getting things dialed in.

I still can't get my performance pipe to work. I get about half the power when the pipe is on vs. stock.
Sounds like you have a tale to tell, friend. :wink:

How did you end up frying it? Any "do not do's" advice? Did it fry on the stock carb? If so what jets did you have in it? Did you do any intake mods? Did you change your fuel mixture?

I say the more factual info we get on here, the more we help each other and anyone else contemplating this kit. 8)
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Post by lovemysan »

blaupunk wrote:
lovemysan wrote:Just be careful you don't want to seize it. How does it run with the filter cover tight? You should be able to dial it in with the mix screw and the cover on tight.
With the filter cover tight it bogs down too much to get into it's power band and runs super rich.

Seams like the intake is essentially acting like a resricter plate, so I was planning on drilling 1 hole at a time only until it runs proper. Does that make sense, so that it keeps it restricted to only the volume of air it needs, but can't pull too much air and end up lean and hot?
Your doing it wrong, you tune idle and off idle transition with the mixture screw and or pilot jet. You tune the midrange with needle height and taper. Midrange to WOT you tune with the main jet. There a number of other factors involved, Keihin has a nice chart on their website that shows what components effect fuel mixture and when. By loosening the airbox or drilling holes your leaning the mixture across the rev range including at WOT. This will seize your motor fast. You tune the main jet first and work your way down the revrange from there. Loosening the air box is a quick and simple way to diagnose an overly rick jetting. Get that mixture screw adjusted.
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Post by blaupunk »

lovemysan wrote:
blaupunk wrote:
lovemysan wrote:Just be careful you don't want to seize it. How does it run with the filter cover tight? You should be able to dial it in with the mix screw and the cover on tight.
With the filter cover tight it bogs down too much to get into it's power band and runs super rich.

Seams like the intake is essentially acting like a resricter plate, so I was planning on drilling 1 hole at a time only until it runs proper. Does that make sense, so that it keeps it restricted to only the volume of air it needs, but can't pull too much air and end up lean and hot?
Your doing it wrong, you tune idle and off idle transition with the mixture screw and or pilot jet. You tune the midrange with needle height and taper. Midrange to WOT you tune with the main jet. There a number of other factors involved, Keihin has a nice chart on their website that shows what components effect fuel mixture and when. By loosening the airbox or drilling holes your leaning the mixture across the rev range including at WOT. This will seize your motor fast. You tune the main jet first and work your way down the revrange from there. Loosening the air box is a quick and simple way to diagnose an overly rick jetting. Get that mixture screw adjusted.
Ok, so I have my new jets that you recommended and I started adjusting the screw.

Current State of my tune:
110 Main Jet (everything said to start rich and tune down...or is this too big?)
45 Pilot Jet (40 and 42 seemed to race too much on throttle blip)
Fuel screw turned 1.5 turns out

I don't know if this is strange, but I'm not noticing much idle change (if any at all) as I adjust the screw. It does make a difference in how it drops back down to idle though. At original setting, it would race and increase rpms for a few seconds following a blip in the throttle (too lean correct?). After turning it 1.5 turns out it appears to consistently fall back to idle properly.

Does this sound right to you? or am I way off base?
Did you have to do any needle adjustments on yours? I might as well order those if I need them too :wink:
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Post by lovemysan »

If its jetted too big it will bog at wot. You'll know right away. Racing at idle sounds odd. Do you have an air leak possibly manifold or carb gasket? That or idle speed screw is set too high. Adjust idle to the slowest speed that it sounds happy. Adjusting idle mixture makes only a minute difference in speed but a big difference in off idle throttle response. So blip the throttle too make sure its happy. 1.5 turns out would indicate your pilot jetting is good. If the midrange is lean you can shim the needle by making a washer out of telephone wire. It's not much but better than nothing. I couldn't find needles for the pb. I can't remember well enough to describe the process of shimming.
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Post by blaupunk »

lovemysan wrote:If its jetted too big it will bog at wot. You'll know right away. Racing at idle sounds odd. Do you have an air leak possibly manifold or carb gasket? That or idle speed screw is set too high. Adjust idle to the slowest speed that it sounds happy. Adjusting idle mixture makes only a minute difference in speed but a big difference in off idle throttle response. So blip the throttle too make sure its happy. 1.5 turns out would indicate your pilot jetting is good. If the midrange is lean you can shim the needle by making a washer out of telephone wire. It's not much but better than nothing. I couldn't find needles for the pb. I can't remember well enough to describe the process of shimming.
I bumped up to my largest pilot jet and I don't have any racing after a blip now.

So my current setup is:
110 Main Jet
48 Pilot
Fuel screw turned 1.5 turns out

The 48 pilot and 1.5 turns out gives a much smoother acceleration as it moves into the powerband.

Testing the fuel screw, I found that it still doesn't change the idle much at all, but it does effect hesitation and coming to rest at idle. I think it has a cleaner 'blip'acceleration and drops back nicely.

Do you remember what your pilot jet was? I'm debating getting some larger ones to test them out, but I'm not sure if it would be wasted money since nobody seems to discuss pilot jet sizes for the 70cc kits.

I also checked the plug after a littletest drive at low and high RPM with and without hills... and the plug looked nice and toasty brown. I think it's close!
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Post by lovemysan »

38 pilot. Your numbers are nice and fat you should be safe. How does it run? accelerate? You get better the more you tune and test. I tried doing the plug chops and the info was inconclusive at best. I did figure out a lean detonation by checking the plug it had little specs of silver material on it. I I took my carb off 20 times trying different settings.
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Post by blaupunk »

lovemysan wrote:38 pilot. Your numbers are nice and fat you should be safe. How does it run? accelerate? You get better the more you tune and test. I tried doing the plug chops and the info was inconclusive at best. I did figure out a lean detonation by checking the plug it had little specs of silver material on it. I I took my carb off 20 times trying different settings.
It runs and accelerates nicely actually for how big those jets are. No stuttering or bogging, just a nice smooth acceleration. I think I may actually be able to back it down to 45 pilot and 105 main and possibly plug a few breather holes as I tune it in, but right now It seams to run well, pull hard even going up hill, and plug chops look good. I need to do some more research on needle tuning, but it seams stable and usable for now. I think gas mileage will dictate whether I try to reel it back in a bit on the jets.

Thanks for the tremendous help!
I WOULD NOT HAVE BEEN ABLE TO FIGURE THIS OUT WITHOUT YOUR HELP!!!!!

As a sidenote:
In doing research on other builds, I also found that the shop that we bought the scoot from did not derestrict it as we had asked and been told it was. :roll:

The exhaust was changed, so that didn't matter, but it did still have the variator limiter in it... when I did the trans work I generally try not to have spare parts, so I put it back in thinking it was needed (since the shop told me it was derestricted). That's why my early tests ran perfectly fine up to 35 mph, but leaned out excessively when I hit 40 to 45, not due to the main jet, but I assume due to it being essentially stuck in a low gear and I was over-revving the motor to hit those speeds without realizing it :oops:

Thankfully it didn't blow the motor, it just stalled out and started back up after 10 to 15 minutes... hopefully it didn't take too much life out of the motor.
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Post by lovemysan »

Don't feel bad I took the airbox face off mine and road around for 10 minutes. Until I noticed it was getting real doggy and wouldn't climb into the powerband. I stopped and it smelled hot. Facepalm! It still ran fine later. It actually could out accellerate my stock r50.
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Post by blaupunk »

lovemysan wrote:Don't feel bad I took the airbox face off mine and road around for 10 minutes. Until I noticed it was getting real doggy and wouldn't climb into the powerband. I stopped and it smelled hot. Facepalm! It still ran fine later. It actually could out accellerate my stock r50.
Oh oh! :oops:

Round 2 is on. :cry:

Wife and I were riding 2 up, running well... then nothing. Just stopped. It was fine when we were cruizing at 35mph. When I took it up to 40 mph for about 4 minutes it died.

Smell plenty of gas in the cylinder.
Checked spark.

Piston is not seized. I took out the spark plug and plugged the hole with my finger to verify at least some semblance of a seal.

One thing I noticed is that there doesn't seam to be any air movement out the exhaust. I would think I should have some pressure out the exhaust when I try to kick start it. I took the exhaust off, and I do feel some air being blown out of the head. Could it possibly be a gasket or a reed?

I'm afraid to take the head off to check it, because I also cannot locate a gasket kit for it seperate from the whole head kit.
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Post by blaupunk »

UPDATE: I pulled the plug and let it rest against the head while trying to start it and I'm not seeing any spark from the plug. When I use my testing light, I do see the light trigger, but it isn't very bright.

Off to try to find some threads about spark diagnosis.
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Post by blaupunk »

blaupunk wrote:UPDATE: I pulled the plug and let it rest against the head while trying to start it and I'm not seeing any spark from the plug. When I use my testing light, I do see the light trigger, but it isn't very bright.

Off to try to find some threads about spark diagnosis.
Ok new question. I found a few topics talking about performance CDI and coils. Would mine have gone bad from running the 70 cc kit? Any information of this wold be helpful.
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Post by lovemysan »

It's unlikely.
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Post by blaupunk »

lovemysan wrote:It's unlikely.
I popped off my Ignition coil and ran some tests. I do get 0 resistance across the pos and neg terminals. Does that mean it is shorted? I also get about 8kOhms from both pos to plug end and neg to plug end.

From the testing instructions I was able to find, this seams to indicate a problem. Right? If so, it very well may have been on it's way out before I put the kit on.
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Post by blaupunk »

lovemysan wrote:It's unlikely.
You were right. I had more time to test. I cleaned my connections and now I get a nice strong spark.

However I picked up a compression tester today(been meaning to get one anyway) and I only read 60 psi (cold engine - obviously i can't warm it since it won't start)... which sounds low :cry:

Does anyone know what psi a 70cc 2 stroke should give?
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Post by lovemysan »

100 psi minimum is what the local scooter mechanic said. . How long is the hose? That will reduce the reading. Kicking or electric starting? Throttle wide open? I've had stuff run at 70psi. My buddy 50 tested at 90 psi 10" hose and was strong running.
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Post by lovemysan »

Forgot to say, if you suspect it's low compression pull the exhaust and inspect the piston for scoring.
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Post by blaupunk »

lovemysan wrote:Forgot to say, if you suspect it's low compression pull the exhaust and inspect the piston for scoring.
Did just that this morning... lots o' scoring. Popped the head and those rings got cooked.

Good thing the head kit is not that expensive at least :roll:

I'm wondering if a lot of that damage was done early on when I was trying to figure it out and ran it way too lean (coupled with over-revving since the CVT restrictor was still in place)

I think this time I am just going to install everything, then putt it over to the nearest cycle shop at 10 mph to see if they can help me tune the carb :lol:
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Post by ironmask »

Wow, this thread is just in time for myself. I just put a 72cc Prima BBK in mine as well.. I am still using stock exhaust, stock jet. I have put 6g Dr. Pulley sliders and a Racing CDI box in it to help. I get about 47mph top speed and it seems to accelerate smoother. I was thinking of only loosening the air box for a short time to see a difference. I do also plan on getting the Leo Vince exhaust which also comes with clutch springs... although I have heard that the clutch springs may be not so effective because the shop I am purchasing the exhaust from says that the one with the stock springs and LV exhaust runs better than the one with the new springs.. I think it is just trial and error for each individual bike in the long run and we will find our happy medium. I don't want to get too crazy with my Buddy 50 and blow it up because it is also my only means of transportation atm. Anyways, thanks for adding to this thread because this is still all a new experience for me and I am a hands on type guy who likes to learn and it has already been lots of fun adding things myself to make my buddy me best buddy! ;-)
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Post by blaupunk »

ironmask wrote:Wow, this thread is just in time for myself. I just put a 72cc Prima BBK in mine as well.. I am still using stock exhaust, stock jet. I have put 6g Dr. Pulley sliders and a Racing CDI box in it to help. I get about 47mph top speed and it seems to accelerate smoother. I was thinking of only loosening the air box for a short time to see a difference. I do also plan on getting the Leo Vince exhaust which also comes with clutch springs... although I have heard that the clutch springs may be not so effective because the shop I am purchasing the exhaust from says that the one with the stock springs and LV exhaust runs better than the one with the new springs.. I think it is just trial and error for each individual bike in the long run and we will find our happy medium. I don't want to get too crazy with my Buddy 50 and blow it up because it is also my only means of transportation atm. Anyways, thanks for adding to this thread because this is still all a new experience for me and I am a hands on type guy who likes to learn and it has already been lots of fun adding things myself to make my buddy me best buddy! ;-)
Thanks for your experience as well. I just replaced the head and put the stock unrestricted exhaust back on. Just been doing warmup/cooldown cycles so far.

From reading around the worldwidewebiverse about other people's experiences, it seams we can get away with the exhaust or the head with the stock carb relatively easily. But as soon as you do both you invite trouble because the stock carb is tough to dial in to deal with it (lovemysan nailed that one above). I'm not insinuating it can't be done (obviously there are some running on it), it just seams to be the common thread I've read so far.


What I've learned about 2 strokes so far:
Carb = Black Magic
2Stroke head = Voodoo
Exhaust = Hocus Pokus

This scooter runs ok on Black Magic and Voodoo, but adding too much Hocus Pokus blew the snot out of it... Needs a dash more Black Magic :D
blaupunk
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Posts: 29
Joined: Sat Jul 27, 2013 8:35 pm

Post by blaupunk »

lovemysan wrote:If its jetted too big it will bog at wot. You'll know right away. Racing at idle sounds odd. Do you have an air leak possibly manifold or carb gasket? That or idle speed screw is set too high. Adjust idle to the slowest speed that it sounds happy. Adjusting idle mixture makes only a minute difference in speed but a big difference in off idle throttle response. So blip the throttle too make sure its happy. 1.5 turns out would indicate your pilot jetting is good. If the midrange is lean you can shim the needle by making a washer out of telephone wire. It's not much but better than nothing. I couldn't find needles for the pb. I can't remember well enough to describe the process of shimming.
Break in #2 seems to be going nicely so far. So far the plug looks ok at low range cruizing. I'm slowly speading up, but right now I'm sticking to about 25mph. I was wondering if you remember if you needed to shim the needle jet on your scoot?
87PGOSTAR50GUY
Member
Posts: 81
Joined: Thu Jan 07, 2016 2:50 am
Location: Seattle, WA

Post by 87PGOSTAR50GUY »

blaupunk wrote:
ironmask wrote:Wow, this thread is just in time for myself. I just put a 72cc Prima BBK in mine as well.. I am still using stock exhaust, stock jet. I have put 6g Dr. Pulley sliders and a Racing CDI box in it to help. I get about 47mph top speed and it seems to accelerate smoother. I was thinking of only loosening the air box for a short time to see a difference. I do also plan on getting the Leo Vince exhaust which also comes with clutch springs... although I have heard that the clutch springs may be not so effective because the shop I am purchasing the exhaust from says that the one with the stock springs and LV exhaust runs better than the one with the new springs.. I think it is just trial and error for each individual bike in the long run and we will find our happy medium. I don't want to get too crazy with my Buddy 50 and blow it up because it is also my only means of transportation atm. Anyways, thanks for adding to this thread because this is still all a new experience for me and I am a hands on type guy who likes to learn and it has already been lots of fun adding things myself to make my buddy me best buddy! ;-)
Thanks for your experience as well. I just replaced the head and put the stock unrestricted exhaust back on. Just been doing warmup/cooldown cycles so far.

From reading around the worldwidewebiverse about other people's experiences, it seams we can get away with the exhaust or the head with the stock carb relatively easily. But as soon as you do both you invite trouble because the stock carb is tough to dial in to deal with it (lovemysan nailed that one above). I'm not insinuating it can't be done (obviously there are some running on it), it just seams to be the common thread I've read so far.


What I've learned about 2 strokes so far:
Carb = Black Magic
2Stroke head = Voodoo
Exhaust = Hocus Pokus

This scooter runs ok on Black Magic and Voodoo, but adding too much Hocus Pokus blew the snot out of it... Needs a dash more Black Magic :D

Va was good. Inbox me about your findi gs with the jets.
At the end of the day when its hot and my scoot is hot we both look sexy wet------- who wan the wet competition?

The scooter, man my scoot gets all the the moped tang unlike its dad it doesnt have wedding rings hahah!
dasscooter
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Posts: 332
Joined: Sun Feb 14, 2016 7:01 pm

Post by dasscooter »

that was like 4yrs ago
87PGOSTAR50GUY
Member
Posts: 81
Joined: Thu Jan 07, 2016 2:50 am
Location: Seattle, WA

Post by 87PGOSTAR50GUY »

dasscooter wrote:that was like 4yrs ago

I know lol and my scoot is 28 years ago HAHAHAHAHA i just found that the documentation was provided so lovley that i was hoping someone would respond due to i have a piolot too big provided that the newer genuine buddy 50 uses 36-42 pilot.

Bad part is my jets have no marking covers sym honda and pgo.


Sea level is my main concern so what would be my base pilot size? Intend on ordering the pilot based two sizes bigger so 3 jets to start with.

Personally diesel after shut off doesnt bother me but running additive i really dont want to do to keep the carbon away.

Mufflers going to kick the bucket sooner or later.


Whats your opinion on jetting as this post described my carb type and specs excluding the 70cc bbk which is cheaper then a honda bbk.


(hungry to learn more) and more til theres nothing left to fix.

The misses is paying for my tabs and plates im stoked like a 8 year old that ate donuts and played at the park the whole day lol
At the end of the day when its hot and my scoot is hot we both look sexy wet------- who wan the wet competition?

The scooter, man my scoot gets all the the moped tang unlike its dad it doesnt have wedding rings hahah!
lovemysan
Member
Posts: 660
Joined: Sun Jan 15, 2012 2:55 am
Location: kansas city mo

Post by lovemysan »

Stock buddy 50 pilot is a 35 and it's not a standard keihen pilot. It's a funny length
161cc big bore kit, NCY big valve head Hand ported, NCY transmission kit, jetted and tuned. I can port your cylinder head.
87PGOSTAR50GUY
Member
Posts: 81
Joined: Thu Jan 07, 2016 2:50 am
Location: Seattle, WA

Post by 87PGOSTAR50GUY »

lovemysan wrote:Stock buddy 50 pilot is a 35 and it's not a standard keihen pilot. It's a funny length

Thanks i knew that 35-36 was the orginal based off my old garbage carb it ran a 36 slow and a 120 main broken.

So should i be using a digital caliper to get those funny threads properly sized. Im getting tired of fixing anything with wheels but for my scoot i want this scooter so cold.

Feelin like a future song, "kneck froze and hands too but ill kick it for my pgo like a Alaskan igloo" lol

Is there a way to get base spec and fine sand the threads to fit specs usually are not too far off.
At the end of the day when its hot and my scoot is hot we both look sexy wet------- who wan the wet competition?

The scooter, man my scoot gets all the the moped tang unlike its dad it doesnt have wedding rings hahah!
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