Im new to the forum so hope I did this right. Just bought a '01 yerf dog 90cc real cheap. It runs, pain in the butt to start though. Once started it will run for about 5 min. then dies. It will start again and run for about the same amount of time before dying. Thru all this the quad loses power, bad. I think it may need a rebuild. How do I check the compression? Is it the same as with a V-8? And does anyone know if a big bore kit can be installed on this brand of quad and if so where I can get one? Just trying to be brief and to the point. Thanks

 

Hi,

Check the exhaust first and see if it has a screen (spark arrestor screen) remove it. Also check the intake filter and tube for any obstructions, restrictions and remove them. If you have a compression tester a fresh (new) motor should test around 140+. If you need parts check out an ebayer named autotech355. He sells lots of aftermarket parts for these yamaha jog type 50/90 2 strokes.

Cheers!

 

Hey verl, thanks for the info. Im gonna pick up my compression tester from my dad's house tomorrow and check it out. But I will make sure there are no obstructions first.

 

Welcome to the forum daddyo4!

Id start by checking compression....

 

edited by atvconnection moderator