Modern Buddy

Greetings All,

I have a Roughhouse and my wife has a Buddy that we purchased last year. Both were 50cc and I had them upgraded to 70cc at a local shop. When we got them back Roughhouse was running perfectly. Goes well up some hills by my house where if I can get up to 45mph that speed holds no problem. Engine is fairly peppy. The Buddy is where I am having problems. When I pull the throttle, it goes strong to about 50%, then goes flat or slightly drops until about 75% where it picks back up again.

I am also having problems where after about 15 minutes the engine is sluggish and accelerates worse then when it was a 50cc. The same hills I can cruise up on the Roughhouse are much slower on the buddy where I am at about 30mph. If I stop I can get back up to speed quickly but it is like after the engine gets warm it becomes sluggish. Any thoughts? I realize the two scooters aren't exactly the same but the Roughhouse runs much better and accelerates the same when cool but Buddy is way more sluggish after 15 minutes and the Roughhouse leaves it in the dust.

I took back to the shop that did the upgrade, they are partially not believing me and saying that these scooters are for lighter asians or shouldn't be run long because they are air cooled. I am frustrated with them and don't want to go back if they can't fix and this is their diagnosis after they have looked at it. Any thoughts of what this could be? I appreciate in advance.

I call BS on that "only for lightweight riders" assessment. I'm close to 280lbs, and a buddy in dead stock form moves me along very nicely. I'd suspect that they didn't jet it correctly, or that there's an air leak. Once it's hot, the metal expands, and things get worse. I'd try another shop, for sure.

the RH and the Buddy 50 have different engines, although they are Minarelli 50cc. I wonder if something isn't quite set up right on the Buddy.

look up Rolling Wrench on youtube. They are based in Denver, although I have no idea as to their proficiency, they put out some interesting videos.

There is definitely something wrong with the way the Buddy was done. Jets could be an issue for sure. I have thought about dialing up Rolling Wrench but they are usually booked for months in advance. I will get it figured out through another shop or call them. Thanks

Modifications and tuning can be a real pain. I installed a 161cc kit on my 125 and have been tuning it off and on for the past 6 months.