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1986 honda spree 50 will not stay running

Posted: Wed Aug 13, 2014 7:37 am
by cindan96
I put a compression gauge on the engine, it took 3 kicks to get compression up to 90 pounds. it will only start for a few seconds if fuel is poured in carb.

Re: 1986 honda spree 50 will not stay running

Posted: Wed Aug 13, 2014 8:05 am
by Wheelman-111
Greetings:

3 Kicks isn't a lot, depending on your Leg Speed. Did you keep kicking a few more times and it wouldn't go above 90? I recommend you kick 10 times or more, with the carb throttle wide open or the carb (but not the reed block) removed and see what the compression really is.

Next add a few ccs of oil through the plug hole and try that test again. If compression really is 90, it may not run strong but it should run.

Re: 1986 honda spree 50 will not stay running

Posted: Wed Aug 13, 2014 2:10 pm
by cindan96
what does the reed valve do, it seems like the engine is not sucking fuel into the cylinder.everything else has been replaced

Re: 1986 honda spree 50 will not stay running

Posted: Wed Aug 13, 2014 3:49 pm
by breaze
cindan96 wrote:I put a compression gauge on the engine, it took 3 kicks to get compression up to 90 pounds. it will only start for a few seconds if fuel is poured in carb.
Hm-m-m, wondering how you are pouring fuel into carb - does this mean you have the air filter off or did you mean you are pouring fuel into the cylinder.

The Spree needs to have the air filter on with a good filter element to create enough resistance so that fuel is pulled into the mix - if you have it off, try putting your hand over the filter hole to "choke" the system.

If you really are adding fuel to the carb and the bowl is not filling on its own, you need to check how your petcock (fuel valve) is working - lots of posts in here on that subject.

good luck

Re: 1986 honda spree 50 will not stay running

Posted: Wed Aug 13, 2014 5:10 pm
by Wheelman-111
Greetings:

The reed valve prevents the air from blowing back out the intake tract when the piston starts its trip back down the cylinder. That way more of it stays in the case, to be sent upstairs through the transfer ports and uh... compressed during the Compression test. If the reeds are off (or leaking) your compression will look low despite good ring seal. However when you said
it seems like the engine is not sucking fuel into the cylinder.
, it sounds like there may be a ring seal or an Acquired Piston Aperture involved.
Acquired Piston Aperture.jpg
Acquired Piston Aperture.jpg (41.88 KiB) Viewed 3075 times
I hope not.