Model 128M05-0026-F1 with no compression.

[mikosh6]

OK so I blame not spotting a slightly opened exhaust valve on my 77 yr old eyesight. Need cataract surgery. I measured the clearances and the intake was .007, the exhaust a whopping .030 Yes it was stuck open a bit. I have it freed up now using carb cleaner. Any suggestions for anything else to spray on the valve stem to help prevent it doing this trick again?

 

[Timdawg]

Thanks Ilengine. No I can only rotate the valves when they're up off the seat, gripping the valve edges with my fingers. I'm just really surprised that I can't see any movement on the compression tester needle. Same with putting my finger over the plug hole, can't feel any pressure at all. Even if valves were seating poorly or compression rings were damaged or worn I would still think there'd be a small amount of compression.

Did you squirt some oil in cyl. To see if it improved? Starter fluid help to start?

 

[kjonxx]

If you have the head off, start at top dead center with piston making sure flywheel magnets are at coil for fire and rotate in direction of run and see if valves are opening and closing when they should, tells you if cam is bad or plastic slipped on camshaft.

 

[mikosh6]

Problem solved. Freed up sticking exhaust valve by spraying stem with carb cleaner then gently tapping valve head with hammer and wooden dowel to seat it properly. Put back together and it's running fine. I'm just wondering if an additive like Sea Foam can help prevent exhaust valve sticking? And a big thank you to everyone for their advice. Appreciate it.

 

[kjonxx]

Problem solved. Freed up sticking exhaust valve by spraying stem with carb cleaner then gently tapping valve head with hammer and wooden dowel to seat it properly. Put back together and it's running fine. I'm just wondering if an additive like Sea Foam can help prevent exhaust valve sticking? And a big thank you to everyone for their advice. Appreciate it.

Remove the valve and chuck the end in drill and use emery paper to polish.

 

[henerythe8th]

Problem solved. Freed up sticking exhaust valve by spraying stem with carb cleaner then gently tapping valve head with hammer and wooden dowel to seat it properly. Put back together and it's running fine. I'm just wondering if an additive like Sea Foam can help prevent exhaust valve sticking? And a big thank you to everyone for their advice. Appreciate it.

I would try seafoam in the gas and maybe some in the oil, if it's OK to put in the oil.
I've had amazing success with Seafoam in gas when experiencing carb issues.

 

[tadawson]

Sounds like your tipping it over caused something to get into the valve guide/stem and cause it to bind.

 

[mikosh6]

Sounds like your tipping it over caused something tomget intomthe valve guide/stem and cause it to bind.

It may well have done but strange part was I eventually got it running by blocking open the choke and it ran great for an hour while I mowed the lawn. Didn't turn it on it's side after that and the next day it wouldn't start at all. Ripped into it and found the exhaust valve stuck open about 0.023". Lifter gap was just over 0.30" and spec is 0.007".

Remove the valve and chuck the end in drill and use emery paper to polish.

That's what I'm thinking I should have done. If it does stick again I'll definitely do that. Thanks for advice.

 

[stoddardt02]

Problem solved. Freed up sticking exhaust valve by spraying stem with carb cleaner then gently tapping valve head with hammer and wooden dowel to seat it properly. Put back together and it's running fine. I'm just wondering if an additive like Sea Foam can help prevent exhaust valve sticking? And a big thank you to everyone for their advice. Appreciate it. I’m my

Problem solved. Freed up sticking exhaust valve by spraying stem with carb cleaner then gently tapping valve head with hammer and wooden dowel to seat it properly. Put back together and it's running fine. I'm just wondering if an additive like Sea Foam can help prevent exhaust valve sticking? And a big thank you to everyone for their advice. Appreciate it.

i just wanted to thank you for replying that it was fixed and what caused it. So many times people hop on, ask for advice and you never know if the problem was resolved. Thanks

 

[jdtm]

Might need to spin the engine with a drill to deactivate the compression release to get a true reading. Is the head gasket good? Blown will cause loss of compression. Also if you whacked something recently the flywheel key may be slightly sheared causing a timing issue. If you are getting a loud bang out of the muffler I would guess you have at least some compression.

Ignition timing may be an issue with running, but it does not affect compression. Maybe it is a long shot, but here is what I found when I had a 120000 series engine that would not start and had virtually no compression. The picture shows things exactly as they were when the head was removed.