Zero Compression Buddy 150CC engine

[rick71454]

Hello BuddyLand:

I may have gotten ripped off big time by purchasing a used 2008 Buddy 150 engine on ebay.

After getting the old engine out and putting in the used engine, I discovered the use engine had a compression of zero, not 120, not 60, but goose egg 0.

Anyone got a constructive idea what it may be other than a hole in the piston?

Thanks
Rick71454

[PeteH]

Broken timing chain, busted valve, blown gasket...

Start by taking off the valve cover and have a look around.

[ohiotj]

If you're lucky, maybe the valves are tight, and not getting closed all the way. I agree with PeteH, start with pulling the valve cover, and see what you've got.

[Throwback7R]

Cracked piston .. what happened to me.. also bent exhaust valve. Failure

reason why I have a 171 kit with large valve head

[agrogod]

I may have gotten ripped off big time by purchasing a used 2008 Buddy 150 engine on ebay.

After getting the old engine out and putting in the used engine, I discovered the use engine had a compression of zero, not 120, not 60, but goose egg 0.

Anyone got a constructive idea what it may be other than a hole in the piston?

Thanks
Rick71454

And this is why you ALWAYS do a tear down of a "new" used motor BEFORE putting it in. A lesson learned.

[Throwback7R]

you can do all the top end stuff with the engine still in the scoot.

[lovemysan]

I may have gotten ripped off big time by purchasing a used 2008 Buddy 150 engine on ebay.

After getting the old engine out and putting in the used engine, I discovered the use engine had a compression of zero, not 120, not 60, but goose egg 0.

Anyone got a constructive idea what it may be other than a hole in the piston?

Thanks
Rick71454

And this is why you ALWAYS do a tear down of a "new" used motor BEFORE putting it in. A lesson learned.

I've replaced dozens of engines in all manner of equipment. All I ever do is verify running condition. If a used engine needs internal repair I ain't buying it.

[rick71454]

Hello BuddyLand:

Thank you all for your help........

When I pushed the kickstart lever down with my foot after installing it, I noticed how easy it went down. No resistance like a good engine. Tell me if I am mistaken, but that confirms the compression is quite low.

Thanks
Rick71454

[ohiotj]

That could also be a broken (or missing) kickstart washer, but is it correct to assume you've tried to start it with the starter, too, and been unsuccessful? I'd assume the starter would turn noticeably faster than usual if there's no compression. If the starter noise/speed seems normal, then I'd assume you've got compression.

If not, then the next thing would be to get a compression tester, and double check with it instead of guessing. Failing that, it'd be time to pull the valve cover, get the engine to top dead center, make sure the timing marks line up, get some shims to check for valve clearance.

If valve clearance and timing are fine, but still no compression, then its probably time to pull the head and look for internal wear or damage.


Edit: Auto parts stores with loaner tool programs should have a compression tester available, so you don't have to buy one.

[rick71454]

Hello OhioTJ:

I like your advice............and thanks.

I tried both electric and kick start. Speed of starting motor seems normal, I am not sure if really normal, but I can see the entire engine rock a little. I did a compression test with a compression gauge and the reading was zero.

I will next take off the valve to check the clearances.

Rick71454

[ohiotj]

One more thing I just thought of if you haven't pulled the valve cover yet. Any idea how long the engine was sitting? If the cylinder is completely dry, you could be getting a low compression number, although I wouldn't think it'd be zero. And if you've been cranking the starter, I'd assume some oil has made it to the cylinder walls by now, so it should be good, but if not, squirting a vey little bit of oil in through the spark plug hole might help.

[rick71454]

Hello OhioTJ:

I suspect the engine had been sitting a long time. I had not taken off the valve cover yet. I will try your idea of the shooting oil into the cylinder.

Thank
Rick71454

[ohiotj]

Hello OhioTJ:

I suspect the engine had been sitting a long time. I had not taken off the valve cover yet. I will try your idea of the shooting oil into the cylinder.

Thank
Rick71454

When you do, just make sure to let it soak for a bit, then leave the spark plug out for a few cranks. It may make a bit of a mess, but don't want to risk (however little it may be) hydrolocking the engine. In car engines, I wouldn't worry about a little oil causing that, but in an engine this small, I just don't know.