1977 115 hp top seal question

[racerone]

If I recall it did not sound very good !!

 

[Charlie5653]

lol, I'll start another thread when all my parts get here and I get it fired back up.

Thanks for all your help..

 

[Charlie5653]

I can't visualize how you could possibly get your finger past the choke butterfly and place it over the idle fuel inlet passageway with the throttle butterfly closed and in the way. However, the rpm change you're speaking of now goes far past a lean setting problem... it indicates a missing problem.

Spark plugs should be Champion QL77JC4 plugs gaped at either .030 (long life) or .040 (strong spark)

Remove all spark plugs and do a compression test... what are the psi readings of "all" individual cylinders.

Plugs still removed... Test the spark which should jump a 7/16" air gap with a strong blue lightning like flame... a real SNAP! Does it?

Joe, I took these carbs off again. There are 4 small holes in the bottom of each throat. 2 of the 4 holes are a bit bigger and in front of the butterfly the other 2 tiny tiny holes are behind the butterfly so when I put my finger in there, I am shutting off some fuel out of the 2 bigger holes.
When the butterfly is fully closed (for idle) it closes with the 2 big holes in front and the 2 tiny holes in the back

 

[Charlie5653]

Update for the pro's !

I replaced 2 cracked coils (old ones tested good however)

I had a clear inline fuel filter I had put on right past the prime bulb (because the boat had set for so long, I wanted to ensure I could see the fuel after I drained the tank, for any dirt or particles I had noticed "small air bubbles" in that see-thru filter when I primed the bulb yesterday???
After running a tank thru on the river and much testing in the tank I was comfortable that the tank was clean. I removed that filter and that seems to have 95% eliminated my idle miss. (was able to advance timing/idle screw back to where it would normally be.) Does this make any sense ???

I now have 750 in tank and around 1100 rpm's on muff idle Sounds pretty good......
Will river test this afternoon and post back.

 

[Charlie5653]

Test went well, will start new thread with results " 1977 115 hp throttle question"