YamahopperTheHorrible

Didn't know they were restricted? Second question is why is a 125 cc bike sold restricted, different laws in different countries? The only reason bikes are sold here in the U.S. restricted is either to make them legally sold as a moped or for a beginner bike. I didn't think that these were being sold as beginner bikes. Is the restriction on the exhuast - a round washer type disc welded into the header?

This is a small engine but with the right gear ratio you can get them up to the 60mph range. Providing that the engine is running properly. If everything sounds good then check the usual, plug gap, compression, etc... Once that is determined you can look at changing the gearing with a smaller rear sprocket. If the bike is used you will probably need to replace the chain and sprocket(s) anyways. You will loose some low end but gain high. Look at opening up the air box or getting a K&N air filter and rejetting if nessecary. I have a chinese 150 stroker copy that gets about 65 but i had to swap out the rear sprocket for a smaller one. Easy speed gain.

Hi, new to the boards here! I have an 85 IT 250 that i recently resurected (well sort of). Bought it non running even though the seller said it ran when he parked 2 yrs ago. It needed a new CDI and i replaced that and got it fired up after flushing and cleaning the carbm, air filter, oil change. I have not been able to get it to run correctly into the mid range and beyond though. If i let it idle for a few seconds then hit the throttle it will resopond but then quickly start to bog within a few seconds. I raised the clip hieght on the main and it is now all the way at the top -didn't make any difference. The carb is clean inside and there doesn't seem to be any sticking on the floats. I have not tested the floats to see if they are water tight though- i read somewhere how to do this but have forgot the procedure???? Seems like submersing them and then checking for any fluid inside would be a good way, but at the same time i would think that if they were not water tight then i would be seeing gas inside when i pulled them out last time? The engine is idling sparaticly at times and has also stuck wide open twice now. I can kill it by holding the throttle wide open when this happens. Is it possible that i am dealing with an air leak on this old girl between the carb and cylinder, or even though it looks clean and in good condition to this untrained eye it may need a carb kit??? I'd really like to keep the bike around and get it in order. I always admired these blue machines as a kid in the 80's. This one is well in keeping with that admiration as the condition cosmetically is very good for the age. Plastic is faded but the bike doesn't look like it ever had much use. -D