i just put a 350x motor into my 250x and I no clue whats wrong but a 300ex stock is killing me in mid range. I need to modifie

 

Change the gearing first. That engine should outrun the hell out of a 300ex.

Is the carb jetted right?

 

Bike is 100% stock, including the stock carb and muffler. I intend to purchase exhaust from Powroll and will jet carb once installed. Another problem is my light won't work. Do you think that could be a statstor problem? Engine starts and runs great. The 3 wheeler the engine came out of killed everything around here.

Any suggestions on how to get the lights working?????

Thanks.

 

Would be great to see some picture of the engine swap

 

Something is wrong with the 350x if it cant take a 300ex.

 

I Have a 350x converted into a quad (sorry). Have pipe, air box, and paddles. It runs right by the 300 ex, the stock 400 ex will be get me by a little. This is pulling the face at Sand Mountain, Nevada in 3rd most of the way, on occasion need to grab 2nd, will not pull the backside, its much steeper. The face goes up 600 feet. FYI

 

ya thats the funny thing the 350x will murder a 300ex and keep up in take off to a raptor.

 

mabe your engine is having electrical problems, and its affecting your performance. try working on the electrical like re-think it all over again. was the 350x engine running real cherry when you bought it.

 

yup the 350x that i baught was complete and it was fast. I think it could be an electrical problem and thats why my head lights dont work