Hey guys, I've been lurking around reading up on all of the fantastic knowledge everyone has given, you guys are awesome! So here's my dilemma. I bought a 2002 Yamaha blaster a few weeks back, ran great, started first kick even cold. First thing I always due in a used bike that has unknown history is change the oil, which I did with yamalube 4. After that, the bike took a out 5 kicks to start and the used oil that I drained had lots of metal shavings stuck to the magnetic drain bolt. After riding another week, it got harder and harder to start. So I popped the plug off, inspected and replaced, then took a compression test and it's around 89 psi which I know is low so now I'm going to attempt to rebuild the top end. One strange thing is there is gas leaking from the front of the bike from a hose thats attached to the right side top end of crank case. Other strange thing is why did it run worse after the oil change. My question, and ease go easy on me lol, is do you all think given these conditions that all I will need is a top end replacement? I'm new to this and I don't want to go chasing my tail, just want to feel the wind in my hair and the speed tears in my eyes. Thank you all so very much for any help!
New rider, need help
- Thread starter Garrettk
- Start date
anything under 100 psi compression is due for a top end rebuild,
fuel out of the trans case overflow is troubling though, the only way that can happen is a bad crank seal or the cases are cracked/broken between the crankcase and trans areas, normally there would not even be enough pressure in the trans/clutch section to push it up and out that hose ? was it smoking excessively from burning trans oil ?
a leakdown test should be done before tear down to see if pressure is getting from the crankcase in to the trans/clutch case area.
fuel out of the trans case overflow is troubling though, the only way that can happen is a bad crank seal or the cases are cracked/broken between the crankcase and trans areas, normally there would not even be enough pressure in the trans/clutch section to push it up and out that hose ? was it smoking excessively from burning trans oil ?
a leakdown test should be done before tear down to see if pressure is getting from the crankcase in to the trans/clutch case area.
Thank you so much! I'll try a leak down test but I have one question. I realized that it's actually not fuel leaking but oil (my bad), so could this be due to bad rings or something in the top end creating more pressure? It's actually pushing oil out of my trans/crank seal also so it's definitely high pressure related. Thanks again for all your help!
OH, and this only happens when cranking the engine. Once started, it runs really good!
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