rarerat wrote:
Havent really had the Pilot out this year and a couple of months back I dug it out for a short spin with some 8 or 9 month old gas in the tank and it really ran bad. I rode it maybe 10-15 minutes and took home and did a compression test and it was down from the normal 138 to 131. I let it sit until today and drained the gas, put in a couple gallons of fresh gas and rode it again about 15 minutes & it seems to run great. I brought it home and rechecked the compression and it was still right about 131. I know it likely needs ringed at the very least & I guess I was just hoping for a miracle and it would be back up to the normal compression but no so lucky . lol..
When I pulled the plug it was pretty caked up with soot or ?? like a dummy I scrapped most of it off before my pics but hopefully you guys can still see it. So I pulled the exhaust expecting to see a scared up cylinder or piston but it looks really good from the little I can see through the exhaust port. I know I really need to pull the top end and inspect everything, but I guess I was just expecting to see some damage through the exhaust port and I don't see anything? The pipe had some build up right in the neck where it attaches to the cylinder but it doesnt look like piston material?? Is it possible to burn the piston top and nothing on the sides?
Do you guys see anything that stands out from these lousy pics?
Is your
Engine stock, no porting stock head?
I would go through the top end if it was mine, you can pull the cylinder and leave the head on to check the rings and piston and if they are ok reinstall the cylinder and it will only cost you a cylinder gasket, just make sure you put the rings back into the same groove, top in top groove bottom in bottom groove and make sure the side that was facing up is still facing up, these 2 strokes unlike 4 strokes have the locator pins so the rings end up back in the cylinder where they were before you took it apart, if your using the same rings you don't even have to hone the cylinder.
A top end gasket kit is not all that much, looking at the plug and exhaust tunnel you will probably want to DE-carbonize anyways.
At your elevation I would run a modified head if your not already set to 49cc you could probably easily get away with a 47cc dome too, for sure the 49cc dome would be good all the way to sea level the 47cc you would need to keep a ear our for detonation, the 49cc might need a jetting change at lower elevations on a dry day.
As you know the Honda manual says to tear down the top end every 30 hrs and inspect, we know that is ultra conservative but probably would not be a bad idea at 60 hrs, myself I never worried about the hours I just ran it hard as I wanted all season long then took it apart for inspection at the end of each season and replaced the piston and rings regardless of their condition, yeah I have a bunch of used pistons I can reuse in the future if need be

You can bet the first time I get a cylinder sleeved the finish bore will be sized to accept the smallest of my used pistons..