I took my quad out for a weekend in the woods, and it did really well. But on the way back to camp just riding normally it started losing power and died. I restarted it a couple of times, but it sounded like it was missing and just weak. A Grizzly 700 had to tow me back. Where do I need to start? The fuel and air filters are clean. It has been running great for a week or so.

 

Sounds like a piston seizure. First check compression,if low(less than 100 psi) the tear down probably needed.

 

also check the flywheel and stator plate to see if they have moved. you might have busted the skirts off the piston too. the easiest way to check that is take the exhaust manifold off and look inside while you slowly turn the motor over see if the piston looks ok.

i would definitely start with the compression check tho

 

It cranks over fine. Could it still be seized? I will try to get a hold of a compression tester this week. What is the proper method of using one? It may be time for a new Griz after all.

 

EASY way to tell if compression is low is to remove plug,place thumb over plug hole and crank,IF cant blow your thumb up or very weak,then you know then where to start! CHEAPER to repair than the cost of a Grizzly!

 

I will do some investigation this evening. Thanks!

 

if it is getting fire then chances are you might as well start pulling the carb and exhaust off to check the piston. look inthe spark plug hole as w/ a flashlight to see the top of piston and check the plug for any debree of metal and see if it looks white on the tip form running too lean.

 

There was no metal on the plug when I pulled it. It was wet with gas, though, and black. No erosion, either. My finger is easily "popped" out of the spark plug hole. I am getting a compression tester tomorrow.

 

try replasing the sparkplug with a new one my 400 just quit that was my trubble it still looked good but did not fire under compression i hope that is all that is wrong with yours

 

I did not know I needed a six pack of plugs per tank to run this machine.