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Stock buddy 50 top end at 1000mi

Posted: Sat Nov 23, 2024 12:32 am
by jk50
Lubrication issue on the intake side of the piston? It was running all stock for most of the 1000. Later it had a sport pipe and 80 jet. Been using Lucas semi syn most of the time. there sure is a lot of oil/fuel pooled in the crankcase.

Re: Stock buddy 50 top end at 1000mi

Posted: Sat Nov 23, 2024 1:36 am
by jk50
Scooter was running fine. 70cc kit going on. It’s difficult to believe the head tourqe is only 10fl lbs haha. 1.4 kg m

Re: Stock buddy 50 top end at 1000mi

Posted: Sat Nov 23, 2024 1:40 pm
by sc00ter
Looks fine to me. Is the Lucas oil pump approved, or is it for pre-mix only? Also, what BBK are you going with? Do you have main and idle jets ready for setting up? And don't forget, you'll have to re-tune your transmission to get the most out of your new power band.

My favorite BBK is the Malossi cast iron. Greta bang for your buck and kinda forgiving should/when you make a mistake. A de-restricted Yasuni Z is a great match or for a little more noise the Yasuni R is great as well. Make sure you run carbon fiber valves is using a expansion chamber. It's cheap insurance should a valve break. On a Zuma bug-eye carbon fiber valves are a must do. Thank goodness I enjoy ebikes so much or I'd be tempted to buy a Rough House and start modding it!

Re: Stock buddy 50 top end at 1000mi

Posted: Sat Nov 23, 2024 7:10 pm
by jk50
Malossi Iron. Got a jet kit from stage 6. They recommend starting with 82. It also comes with a pilot jet. I found the stock carb does not seem to have a cap on the idle mix screw, it’s epoxied in place so.. have a stock replacement unit coming with an adjustable mix. Currently have an out of the box Malossi varriator kit on the scooter. The kit comes with carbon fiber reeds. Lucas is premix and injection. I also have Yamalube s, and Philips 66 airkool oil.

Re: Stock buddy 50 top end at 1000mi

Posted: Sun Nov 24, 2024 12:44 am
by sc00ter
Nice! I tell everyone to take tuning in stages/steps. Stage 1-Entry level expansion chamber and variator. Stage 2- Cast iron 70cc and a mid-level expansion chamber. Some expansion chambers can do both 50cc and 70cc. Next would be a Stage 3- Bigger carb, aluminum 70cc and a matching expansion chamber. Anything higher usually consist of a liquid conversion and a more serious level of tuning. Note that some variables can cross over and I left out a lot of the details that really make a good tune shine. I was happy with a solid 57mph with powerful acceleration. My old riding friend like 65mph and aggressive acceleration. He also didn't mind keeping it running strong or spending the money for the finer details.

I have a guy at work who had a mild tuned Vespa 125 shifty. He won it at a raffle and the builder wasn't thorough with the scooters light tune. When something dumb failed the guy just jumped into a Malossi case set and a full BBK. He locked the motor up so bad about week later on a longer ride. I think that scooter is still down. I would have gone thru it after winning it and then learned tuning as I went along, not just jump into a serious build without the basic knowledge.

So take your time and learn. It's very rewarding when you get it right and you can stomp on any Chinese 50cc AND most all China 150cc scooters. I used to like beating on Groms myself.

Re: Stock buddy 50 top end at 1000mi

Posted: Sun Nov 24, 2024 4:13 pm
by jk50
I just have a sport exhaust though.

Re: Stock buddy 50 top end at 1000mi

Posted: Tue Nov 26, 2024 12:20 am
by sc00ter
A sport exhaust will pair well with a cast iron BBK.

I wonder if the air mixture plug can be removed, like on most stock Zumas.

Re: Stock buddy 50 top end at 1000mi

Posted: Tue Nov 26, 2024 2:02 am
by jk50
I don’t think it’s a plug. Seems like Jb weld and brazing? It must not be just a plug if a stock replacement with adjustable mix is sold.

Re: Stock buddy 50 top end at 1000mi

Posted: Wed Nov 27, 2024 9:05 pm
by sc00ter
I had a Buddy 50 for a short time. I recall noticing no air/fuel mixture screw at all, not even a capped off access. I found that weird. If possible, post a picture of this plug/cap thing on the original carb. You have my curiosity going now!

Re: Stock buddy 50 top end at 1000mi

Posted: Wed Nov 27, 2024 11:03 pm
by az_slynch
The Buddy 50 doesn't have a mixture screw on its carb. The Roughhouse 50 does, though.

Re: Stock buddy 50 top end at 1000mi

Posted: Thu Nov 28, 2024 1:01 am
by jk50
It’s there… covered with JB weld, and it appears the flat on the screw filled in. I tried to scrape the Jb weld away to turn it but gave up and just ordered the carb with the adjustable mix. The jet kit I got from sigma 6 kinda requires an adjustable idle mix. The pilot jet is actually slightly smaller than factory.