motomanmike
12-04-2011, 05:04 PM
I've got an 01 400ex with who knows what done to it I bought from a guy a few months ago. Its not your average 400ex because it is very fast compared to my stock 05. It was said it had a hot cam and a slightly higher compression piston i'm guessing 11.1 because it runs on pump gas However there is a pretty annoying leak at the exhaust headers. Rather under the headers, i've taken the rocker cover off and verified it is not the oil seals that hold the rockers in on the allen bolts nor is it the rocker cover gasket itself. Strange thing is it doesnt smoke out the exhaust, compression test are in spec around 120-125 cold but when you ride this thing it leaks bad. Bad enough its leaking on the cylinder and the residual oil is smoking when you cut the quad off due to the oil burning on the head. Would something as simple as valve guide seals cause this or is the problem deeper like valve guides worn? I would think it would smoke out the tail pipe if that was the case from my experience, I HAVE ABSOLUTLY NO SMOKE AT ALL OUT THE TAIL PIPE AT IDLE, WOT, OR DURING DECELERATION. The quad does not smoke at all, runs awesome however leaks oil under the exhaust. I havn't pulled it all apart yet other than popping the rocker cover off thinking that was the issue at first. Thoughts? Seems to be a common issue though i was looking at used heads on ebay and there is another one that has the same oil saturation mine does on the front.