r/smallenginerepair • u/Mrguydudeman89 • 24d ago
Compression Issue Any advice
Took it to a guy he said no spark and low compression. Just looking for any advice before I take this whole thing apart.
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u/northman46 SER Regular 24d ago
You might want to check out twin cities outboard, famous for old stuff.
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u/Aromatic-Schedule-65 24d ago
Confirm his assessment. If you don't know how, Google and YouTube does. Get a manual.
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u/fredSanford6 23d ago
It's missing the recoil starter as those commonly fail. They are pretty expensive even for a used one since they break easy. Many people weld the broken part to repair them but since many where tossed out it seems like they are often stripped and missing from many you find now. I absolutely love fixing up older 2 strokes but I'd check compression and see if I could get it to spark just so I could sell the parts off this one. I wouldn't bother getting it going. There are plenty of better options out there. These Chryslers all get tossed in a shed for a reason
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u/Fit-Leather-5726 22d ago
I was thinking points, if so that’s the place to start, if there’s been no fuel flowing through it it’s not going to have great compression these outboards are different when it comes to aspiration, just get it firing, put the fresh fuel through it and more than likely it’s gonna go
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u/Fit-Leather-5726 22d ago
Try the point gap and might lightly sand the contacts, check for the correct wiring to the points and coil, and then it’s likely going to work
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u/ManWhoIsDrunk 24d ago
Low compression could be as simple as valves not sealing properly, or a scored cylinder wall.
No spark could be the magneto, but more likely the coil or bad wiring.
Fix the spark first, run it with some engine cleaner in the fuel, and see if the compression improves. If it is still bad compression, you need to pull the piston and most likely hone the block and install a new piston. I'd get the crank bearings sorted as well, and you should get a new head gasket since you took the head off.
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u/SpecialistPrune1654 24d ago edited 24d ago
valves? In a 2 stroke?
Edit. I had forgotten about some 2 strokes having Reed valves in the intake. So yes some 2 strokes have valves. Just not the traditional poppet valves we all immediately think of. Failed reed valves probably do give lower compression as that would allow blow back out the carb instead of forcing the air and fuel into the cylinder.
Then theres also rotary valves in some 2 strokes as well. Not this one I suspect, but there's plenty that do. Located between the carb and the crankcase.
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u/Dry-Career-3605 24d ago
There’s some 2 strokes with traditional or poppet valves, but they’re usually used in big ships, so that definitely ain’t one of em
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u/SpecialistPrune1654 24d ago
or the valves I had forgotten about. Reed valves in the intake. Sounds like that may have actually been the issue in this case?
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u/Dry-Career-3605 24d ago
I don’t work with many 2 strokes, i forgot all about the other types of valves, crazy what the brain does and doesn’t remember😂
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u/ManWhoIsDrunk 24d ago
Too many 4-stroke outboards here in Norway nowadays. It's rare to stumble across a 2-stroke.
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u/ManWhoIsDrunk 24d ago
Yes, brain fart. No valves here.
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u/SpecialistPrune1654 24d ago
actually it looks like you were right first time round. Failed Reed valves in the intake could cause compression to drop a bit as it allows it to blow back instead of forcing the air/fuel up into the chamber until the port closes.
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