Post by scooter on Oct 11, 2014 13:27:22 GMT -5
Some time back I wrote a post about oil getting all over my engine bay.
itistheride.boards.net/thread/6402/blowing-oil-mess
Thank you all for your replies.
I wanted to update you on this because I think I may have found the problem. You be the judge and tell me if you agree or not.
Using gasket sealer really helped a lot, and really reduced the amount of oil leaking, but my valve cover always started leaking again, not as bad mind you, after a bit of running. I replaced all of the hoses and made sure nothing was clogged.
This last time that I checked the valves, the exhaust valve was too tight AGAIN. I have adjusted the valves at least 4 times since I got the scooter in June.
This last time, the little vent hose on top of the gy6 150cc was blown open, ripped at the outlet, perhaps indicating pressure issues.
So, in an effort to reduce the time between valve clearance adjustments, I opened up the clearance on the exhaust side to .007 and I think .005 on the intake side. Now it's clicking as the rockers slam into the valve stems BUT, even after a week of running, I finally see NO OIL LEAK! Woohoo!
I did some reading and found this scooterbbs.net/board/DCForumID11/6779.html where they discuss just such issues.
"I have recently had a suspicion of mine confirmed by an independent source regarding a particularly common problem with many if not all, chinese GY6 125 and 150cc motors.
I have seen in the last year that a very large number of cases coming in for repair had problems related to the exhaust valve on these 2 valve 4 stroke motors. It has been extraordinarily common to have to adjust the exhaust valve in the first 5000 miles. We have seen it so frequently, we have become expert in finding they problem by looking for key symptoms.
First, loss of power over 35 mph, or the motor simply wheezing and acting like it had shut off, only to return to power once you release throttle, but again losing power at above 35 mph.
Second, really dirty plugs very early. This is also frequently accompanied by oil leaks under the bike, or more commonly, oil on hte floorboard or underfloorboard areas. This is from back pressure blowing oil out of the top vent on the valve cover."
So I'm thinking this may have been the problem.
Exhaust valve not closing properly, blowing air into the valve cover, blasting oil out of any place it could get out. What do you think? Sounds reasonable?
itistheride.boards.net/thread/6402/blowing-oil-mess
Thank you all for your replies.
I wanted to update you on this because I think I may have found the problem. You be the judge and tell me if you agree or not.
Using gasket sealer really helped a lot, and really reduced the amount of oil leaking, but my valve cover always started leaking again, not as bad mind you, after a bit of running. I replaced all of the hoses and made sure nothing was clogged.
This last time that I checked the valves, the exhaust valve was too tight AGAIN. I have adjusted the valves at least 4 times since I got the scooter in June.
This last time, the little vent hose on top of the gy6 150cc was blown open, ripped at the outlet, perhaps indicating pressure issues.
So, in an effort to reduce the time between valve clearance adjustments, I opened up the clearance on the exhaust side to .007 and I think .005 on the intake side. Now it's clicking as the rockers slam into the valve stems BUT, even after a week of running, I finally see NO OIL LEAK! Woohoo!
I did some reading and found this scooterbbs.net/board/DCForumID11/6779.html where they discuss just such issues.
"I have recently had a suspicion of mine confirmed by an independent source regarding a particularly common problem with many if not all, chinese GY6 125 and 150cc motors.
I have seen in the last year that a very large number of cases coming in for repair had problems related to the exhaust valve on these 2 valve 4 stroke motors. It has been extraordinarily common to have to adjust the exhaust valve in the first 5000 miles. We have seen it so frequently, we have become expert in finding they problem by looking for key symptoms.
First, loss of power over 35 mph, or the motor simply wheezing and acting like it had shut off, only to return to power once you release throttle, but again losing power at above 35 mph.
Second, really dirty plugs very early. This is also frequently accompanied by oil leaks under the bike, or more commonly, oil on hte floorboard or underfloorboard areas. This is from back pressure blowing oil out of the top vent on the valve cover."
So I'm thinking this may have been the problem.
Exhaust valve not closing properly, blowing air into the valve cover, blasting oil out of any place it could get out. What do you think? Sounds reasonable? 
I can have all this work do for pretty much nothing. The machinist wants a case of beer.
hp (2.20 kW) at 7,500 rpm 39 mm × 41.4 mm (1.54 in × 1.63 in) 10.5:1