Buddy 125 wont idle

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Vespaluchi
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Buddy 125 wont idle

Post by Vespaluchi »

Hello all and welcome to my first post. I am a Vespa guy, a vintage Vespa guy, but I got this buddy. My buddy gave me this buddy. It sat for some years, and then it sat some more. Covid got me clearing out scooter graveyard and I got to work on this little guy. Its a mid 2000, 06, 09 maybe. Cant remember off the top of my head.

Anyway, new battery, drained tank with fresh gas, and a fresh carb clean later I am having an issue. At first I couldn't make speed. It started, and idled just fine. Get on the road and I cant get over 40. Its the CV boot. I re-seat it, and boom. I'm making power, but it does not like to idle. It has a new idle jet by the way.

New Fuel filter, a fancy prima one I can see into. One odd note about that, when I installed it. I pulled the old one and gas was gushing out. I thought that was strange because you needed vacuum pressure to work the fuel petcock. When running it appears to have very little fuel in the filter. After it sits a bit, the filter is full. I went to start it cold and while it cranks right up it just does not want to idle. It will rev a bit high, then settle down, then die.

If I screw the idle screw in all the way it will idle, but I know somethings wrong. It revs super high when I lay off the throttle before settling down and it never really sounds right.

Also has a new air filter.

This is a link to a video of it running right after coming back from a test ride.

https://www.youtube.com/watch?v=u2RMTcK ... pf3YQ288-A

What the hell is going on?

edit: This video was shot after hours of sitting and a cold start.

https://www.youtube.com/watch?v=y7keWVC ... e=youtu.be
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JettaKnight
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Post by JettaKnight »

New idle jet?


Well I got nothing.
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Vespaluchi
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Post by Vespaluchi »

Brand spanking new idle jet.

I just checked the valve adjustments and re-set them. Same issue.

I did the ol spray starting fluid around hoses and manifolds to find a leak. Nothing.

This is very discouraging.
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Vespaluchi
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Post by Vespaluchi »

The fuel draining issue when the scooter was off has me thinking the petcock is no good. I read a thread about a guy having a similar issue and the petcock replacement fixed it. There goes another 10 bucks.
scootERIK
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Post by scootERIK »

Have you tried adjusting the air/fuel screw?
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Vespaluchi
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Post by Vespaluchi »

scootERIK wrote:Have you tried adjusting the air/fuel screw?
I fully rebuilt the carb. I screwed the air screw back in (2 1/2?) to find the right setting and put it back where I found it. I have not touched it since. I suppose I could mess with it. Taking it our ads air or fuel?
scootERIK
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Post by scootERIK »

Vespaluchi wrote:
scootERIK wrote:Have you tried adjusting the air/fuel screw?
I fully rebuilt the carb. I screwed the air screw back in (2 1/2?) to find the right setting and put it back where I found it. I have not touched it since. I suppose I could mess with it. Taking it our ads air or fuel?
I am not super knowledgeable on it but I can point you towards a few threads on it-
http://www.modernbuddy.com/forum/viewto ... adjustment

http://www.modernbuddy.com/forum/viewto ... adjustment
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babblefish
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Post by babblefish »

If I'm not mistaken, the idle mixture screw should be turned 1-1/2 turns out from fully closed as a starting point. The final adjustment is pretty close to that.
Some people can break a crowbar in a sandbox.
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Vespaluchi
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Post by Vespaluchi »

babblefish wrote:If I'm not mistaken, the idle mixture screw should be turned 1-1/2 turns out from fully closed as a starting point. The final adjustment is pretty close to that.
Well, I think I found the problem. When I pulled the carb to clean it, I remember running the mix screw in to see where it was set. I cant recall if it was 1 1/2 or 2 1/2 and damn if I cant find any info on this including the buddy service manual. Anyway, I rebuilt the carb and reinstalled. So this morning I thought, let me run that screw back in and mess with it and see if I cant get a different result. I just looked at it and there is no screw!!!!? WTF? I started the scooter and put my finger over the whole and was able to dial the idle down to an acceptable range. Somehow, from riding it from my storage to my shop the screw must have come out. I cant imagine how, but there is not frak screw!!!

sigh.

So, now I need to find one, and the spring. FML.
dan v.
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Post by dan v. »

I had to find parts for the carb on my 250 Kymco, and found the Buddy had the same carb body, but different throat size. The small parts are the same.

The Vespa GT200 uses the same Kehin CV carb, so another parts source.

Also try your local Harley shop - probably your best bet to easily find the parts you need. The Harley CV carb is a Kehin, and the small parts will interchange.

Good Luck!
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Vespaluchi
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Post by Vespaluchi »

dan v. wrote:I had to find parts for the carb on my 250 Kymco, and found the Buddy had the same carb body, but different throat size. The small parts are the same.

The Vespa GT200 uses the same Kehin CV carb, so another parts source.

Also try your local Harley shop - probably your best bet to easily find the parts you need. The Harley CV carb is a Kehin, and the small parts will interchange.

Good Luck!
I ended up ordering it from Scooter Lounge. It has a O ring and a washer along with the spring apparently. I do not recall seeing the oring when I disassembled it so I am guessing thats why I lost the screw.
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