Engine Trouble Low compression

[noah9988]

I have a cdhpower high compression head, allegedly 5.5cc. I decked the cylinder and have the correct squish at around .8mm. I can roll the bike forward with no extra weight on it and the tire will drag for a bit, but it will turn the engine over. Every gasket and mating surface has rtv on it. I made sure that it has no leaks from the crankcase bearings, intake, reed valves, base gasket, head gasket, spark plug, and exhaust. Another thing I noticed is that my engine performance suffers quite drastically when the engine is hot. I'm thinking that the rings aren't sealing properly? And when it gets hot they seal worse? My cylinder also has some scratches in it that I can feel with my finger/nail. That's about all I can think of at this point.

 

[YetiWoodz]

Is it a pain to cold start your bike/does it take longer than 5-10 seconds?

 

[DieselTech]

Pictures help! You doubt me that cylinder head is 5.5cc? I was the only 1 to mention that in 1 of your old posts. We need some pics of your set up because it helps to diagnose it. What does cylinder look like? what's head gasket look like? What's the piston look like in cylinder bore at top dead center? What's things look like after you have ran the engine, what's piston rings look like?

 

[noah9988]

Is it a pain to cold start your bike/does it take longer than 5-10 seconds?

Nope, it starts fine. I put it on full choke, and it fires right off. I can take it off choke right after.

 

[noah9988]

Pictures help! You doubt me that cylinder head is 5.5cc? I was the only 1 to mention that in 1 of your old posts. We need some pics of your set up because it helps to diagnose it. What does cylinder look like? what's head gasket look like? What's the piston look like in cylinder bore at top dead center? What's things look like after you have ran the engine, what's piston rings look like?

No I don't doubt YOU it's 5.5, I doubt the Chinese manufacturers. If you said you measured it I wouldn't have said allegedly. Anyway, I was just riding it and I'll take the head off and get pictures after it cools. Keep in mind that I ran it with 25:1 conventional just now to see if it would create a better seal. I don't think it made a difference.

 

[DieselTech]

I'd keep running it for a while then, unless you are concerned about the low compression. My bike is hard to start on blacktop pavement, compression wise that is. I weigh 140lbs & my bike slides the rear tire on pavement trying to start it. If I'm on gravel, good luck getting it started without it really sliding the tire.

 

[YetiWoodz]

The tire sliding on the pavement is a clutch slipping issue. It shouldn't do that when starting or at all. Clean your clutch pads with brake cleaner or replace them if needed. See if the clutch arm is properly tensioned too. You don't want it to squeal either.

 

[noah9988]

Here are some pictures. Don't mind the white stuff on the spark plug threads, that's thread sealant. I'm surprised to see that carbon buildup, I never had any with the other oil I was using. It looks like my head gasket is still leaking a bit.

 

[DieselTech]

Trust me my clutch is not slipping, let me refraise it, its skidding the tire b4 it starts turning the engine over & starts up.

 

[noah9988]

The tire sliding on the pavement is a clutch slipping issue. It shouldn't do that when starting or at all. Clean your clutch pads with brake cleaner or replace them if needed. See if the clutch arm is properly tensioned too. You don't want it to squeal either.

Nah I mean if I just push the bike the engine turns over without me on it. I was implying that it means it has low compression. I doubt I have a clutch issue.