Hmm small update:

Just came back from riding...pushing the quad

I was rolling at a slow rpm going somewhere when it just start bogging like it was short on gas...Would idle but no go over 1/8 throttle without stalling. Checked the fuel valve, fuel tank and spark plug...plug was nice, but the spark was yellow (not blue) and somehow weak. Changed the plug for a new one, same thing.... The quad don't start anymore now. I think my coil finally quitted me...Hope it's that...Any inputs welcome

Thanks

 

Ok solved the problem about the bogging, the needle clip kinda exploded in the carb so the needle was stuck in the main jet at any RPM lol

Not solving the spark problem though...


Something else strange about my rad, the refill tank fill itself from the rad lol...It should be the opposite, the refill tank is supposed to fill the rad [img]i/expressions/face-icon-small-confused.gif[/img] What could cause that?

 

Yup...sounds like the Radiator cap. Here is how your coolant reservoir works when the cap is good. As the coolant in your system heats up it expands. The radiator being completerly full, has no room for expansion so the resulting pressure pushes the coolant past the seal in the cap and into the reservoir. Only a small amount of coolant will push into the reservoir, just enough to make room for the expansion and no more.
As the engine cools off the coolant retracts creating a vacuum in the radiator which sucks the coolant back into it via a one-way valve in the cap.

If the cap is bad, it will not allow any pressure to build because the coolant just flows past the seal and into the reservoir. Eventually this loss of pressure control over fills the reservoir and your coolant runs onto the ground. As you loose coolant the engine runs hotter and continues creating more pressure which pushes more coolant out of the reservoir.
Now, the good thing is that the cap is easy to check and doing so takes less time then it took for me to write this LOL. Do a visual inspection of the rubber seal looking for any obvious damage. If that was not conclusive have the cap pressure tested in the same manner that you had your radiator pressure tested. It should build to 14 PSI before leaking off. Better yet, just repalce it.
Oh, and Be sure that you use a 50/50 mix of antifreeze in your radiator otherwise you will damage your cylinder and head.

PS just read your post regarding spark, You already diagnosed your coil as being bad and that is where your spark comes from. If the coil is failing, the spark will be orange and weak.

 

Thanks a lot, I'll try that

Anyways, I've checked and the free play in my flywheel, even minor, is already too much. So I'm now gonna split the case to change the main bearings....I'll be out of riding for some time [img]i/expressions/face-icon-small-sad.gif[/img]

 

Don't forget to check the rod bearing - replace it while the crank is out