8hp dying on acceleration

[mitch184]

Ok I'm glad it wasn't just me being an idiot. Seems real odd its listed nowhere

[TownsendsFJR1300]

It's not listed on Sims either..

[mitch184]

Just a mid term follow up..... FYI... these motors dont have a head gasket. Hence why no one could find a part number. It's called a split crankcase design I guess.

So..... only other possibility i could think to allow water into the cylinder was if the exhaust manifold gasket was leaking and water was being sucked in through reversion.

So... pulled those gaskets. nothing glaringly obvious. But with compression as good as it is it's my only thought.

[99yam40]

If this is a water cooled motor, even without a head gasket, it still should have water jackets around the head.
a crack or corrosion hole could let some water in

[mitch184]

Ok. So new exhaust cover gaskets. New fuel pump. Carb is spot less. All new carb gaskets. New primer bulb, new fuel lines new strainer.

Takes a little while to fire up. Primer bulb is hard. Idles good. Can slowly rev it up no problems. But if you hold it at mid rpms it dies. Blip the throttle and sometimes you can save it.

plugs are still spotless after 3 minutes of trying to run. Smoke is bluer to grey.

[mitch184]

Ok... finally solved this. To summarize, completely rebuilt carb, new plugs, new exhaust gaskets, new cylinder head cover gaskets, new fuel pump, new fuel strainer, new fuel lines.

What was it........ the majority of the exhaust in the lower unit was clogged. Yes I'm serious. I cleaned it and now the motor runs flawless.

[TownsendsFJR1300]

Glad you found it.. Was the engine run on pre-mix I gather?

Just curious why it was so clogged much down there, likely too much oil (or cheap oil?)...

Beside running the proper mix(could have clogged up from the PO), perhaps running non-E fuel and also some Ringfree regularly should help in the future..

[99yam40]

yea, what was it clogged with?

[mitch184]

There was some sand mainly and some soot/carbon on the inside. Not exactly sure but I'm thinking just by chance I reversed in a sandy bottom then I did the dead carb which broke some crud loose. The combo clogged it just enough.

[panasonic]

How do the plugs look now? You would think they would have been black and oily with exhaust plugged up...not super clean like you posted. Stange problem for sure..but you got it sorted out.

[mitch184]

Plugs look great now. I mean I'm 90% sure there was water in the cylinder and that's why everything was so clean. Maybe the lower unit was filling with water and getting sucked back up?? Or maybe it was actually just way too much raw fuel washing everything clean?

No clue. Just glad it runs good now.