So i have a very odd situation. I have an 03' yz450F. recently i replaced the impeller shaft, impeller, bearings, and both seals. I rode two rides before i had to put it up for the winter.
Upon taking it out, after winter storage, 5 kicks and it started right up, i let it idle 2-3 minutes to the point of getting its usual cherry hot. And shut the bike down and went inside for my gear.
I took it up the road to my buddies house, and upon stopping i had antifreeze all over my pants, crotch. Coming back i noticed it was spewing out of the radiator Cap and it was almost frothy.
During winter storage since i had just done the water/pump etc, it had fresh 50/50 mix.
I did a few tests, and noticed that 1st and 2nd gear when the bike was revved high, it was ok. Only when i revved it high in 3rd or 4th, did the antifreeze start spewing outta the radiator cap, which makes absolutely no sense to me. I can rev the bike in neutral, and it wont spew fluid out of the cap. Considering the impeller is crankshaft driven, and not gear drive, what the hell is causing this?
I'm assuming a blown head gasket? The guy i bought the bike off, said he had replaced the rings and gaskets. So i'm a bit worried if it blew another head gasket. Perhaps he warped the head, torquing it wrong?
Guess i'm just asking for a few spots to check. I already bought a new radiator cap thinking that might be it. no go...still does it.
my local mechanic i dont think has a leak down tester....but he does have a cooling system pressure tester.
Should i have him pressure test my cooling system? (i'm a bit afraid he may force antifreeze back into cylinder, if he does this).
suggestions folks? or should i just get a new head gasket, pop it in, and grab a mirror and check flatness of head? (i've never worked on 4 strokes before really in the cylinder area)
EDIT: This bike runs flawless, carb issues worked out, etc. but for some reason, i keep getting coolant issues, its beginning to annoy me lol. getting sick of smelling anti-freeze.
Oh, and can anyone suggest or rather link me a good deal on a descent Leak Down Tester? =)
Edited by grayracer513, May 26, 2015 - 06:37 AM.