Bad bottom seal?

[53150]

1980 Johnson 70hp.<br />Could a bad bottom seal make #3 carb act like it is flooding? Iv'e checked the compression rebuilt, and cleaned (very well)the carbs. Checked the timing and spark. If I'm understanding the theory of operation correctly a low vacuum signal to the carb could keep it from properly atomizing fuel and maybe make it flood the cylinder. Am I way off base here or what?<br /><br />Thanks <br />Will Vaughan

 

[Yepblaze]

Re: Bad bottom seal?

A bad seal would make for nearly unusable idle screw action. Poor or no power from that cylinder. Maybe a leaner looking plug reading.<br /><br />Flooding will usualy be recognisable because of the raw fuel running out of it.<br /><br />A broken reed might (maybe,almost,but not quite) run as you describe and want to try to kick in with some added choke.

 

[53150]

Re: Bad bottom seal?

The carbs on my engine don't have idle screws. The reeds are good. With the engine running the fuel coming into the throttle bore on #3 carb is just coming out in drops not atomized. Pulling #3 plug wire off provides no change in engine idle. pulling #1 and #2 off (seperately) cause the engine to die.<br /><br />Thanks <br />Will Vaughan

 

[Solittle]

Re: Bad bottom seal?

Will - I would bet that you still have some crud in the carb. Did you soak it overnight and then use high compressed air to blow out any crud left in the passages that you cannot see?

 

[Yepblaze]

Re: Bad bottom seal?

If it's been idled much, you might try removing the exhaust cover and look for carbon plugged exhaust port(s)

 

[Walker]

Re: Bad bottom seal?

Make sure the small ring gasket that goes on the tower for the pickup tube is good. I've seen carbs throw out gobs of gas when the seal here is not good.

 

[53150]

Re: Bad bottom seal?

I think I might have found the problem. Iv'e got to get every thing put back together first, but I found that the cylider drain on #3 intake port was not plugged in and the check-vavle was missing. I know it was a vacuum leak and I think that was my problem. Iv'e had 2-stroke four wheelers do the same thing sort of.<br /><br />Thanks<br />Will Vaughan

 

[53150]

Re: Bad bottom seal?

Went to the local outboard shop today to get a check valve for the #3 intake drain, their breakdown doesn't show one. The Seloc manual I have gives instructions on checking it so I assumed my engine should have one, or does the hose just plug straight into the carb. cover?<br />1980 Johnson 70hp.<br />Thanks <br />Will Vaughan