i have a 2001 grizzly i was riding it last weekend and it was running fine i could go 50-55mph stopped for lunch got back on it it would only go about 35mph. so far i have cleaned the carb,checked all the wiring, new spark plug,put new gas in it,new air cleaner. anyone have any ideas? valves? clutch rollers? [img]i/expressions/face-icon-small-sad.gif[/img][img]i/expressions/face-icon-small-confused.gif[/img]

 

Sounds like its time to do some primary maintenance.

I noticed mine wouldn't get up past 40, so I tore mine down this past week-end and seviced it, now it's back up to speed...

 

yeah thats what I'm tearing into tomorrow.thanks

 

so i've done whole clutch thing and thats not the problem, so now i am unsure what to do. i think i will dig a hole and push it in.

 

May sound stupid...make sure your not in low range.

 

the problem is there is only 50 ponds of compression. so now i have taken the top end apart and have found the rings are ok. the valves and piston have alot of carbon on them. way more than they should. and i think the head gasket is bad cause of all the oil under it. i'll let you know how it turns out

 

its very possible that the carbon build up is stopping the valve from getting a good seat, actually very common. i've seen it on all types of motors, might as well do a complete valve job now that its apart, but i've solved lack of compression loss simply by squirting decarbon fluid in the spark plug hole and spinning the engine with the plug out.
have you checked your spark arrest? see if thats blocked with carbon

 

i had this same problem on my 98 yamaha grizzly 600. it has 27 inch vampires and the exhaust is changed up some with a car muffler and bigger piping. otherwise stock. but it only runs 35mph and takes awhile getting there. it starts up no problem and blow no smoke at all. i regreased the primary clutch part and nothing changed. any ideas for me? i ordered a new belt in case its slipping some. i even rode it around with no cover on so i could watch the belt and it all looked fine. I NEED HELP!!! email is toyotaman92@hotmail.com