1990 Johnson 70 j70tlesb Close but still need help!

[jhotch]

I posted about this engine surging a while back. Since then I have replaced coils and power pack. condition improved but still surged after a minute at wot. Found some material in carb I (papery). cleaned it and problem continued. Decided to try pumping the bulb while it was surging and found that if I pumped it vigorously I could get it to stop surging. I mean very vigorously... Pulled fuel pump a part and found that the gasket was blown ( possible source of papery material in carb). got a new fuel pump ( the center screw of old one busted when I was taking it a part). put it on and it ran terribly. blocked carbs with my finger and found second cylinder not reacting when blocked. Pulled it a part and found more paper in the needle seat. removed it cleaned it and engine was almost there, but still slight surge that was curable by pumping primer bulb. Decided to try small electric fuel pump 1.5-4 lbs pressure. Boat ran with no surge at wot but now is kind of boggy and will not break past 3200 rpms... Thoughts? I’m thinking to test with a slightly stronger fuel pump? Also Engine was bought from Kingman AZ at 300 above sea level and I live in Southwest Colorado at 6500’ above sea level...
Link and sync seems good slow forward idle at 720
have not been able to set timing because I can’t get it to stay at 5000 rpms. Fuel mixture setting seems close

 

[racerone]

At 6500' you need to change carburetor jets.----Maximum timing is the one you set and it is fixed at the factory.---Only goes out of adjustment when a novice works on these motors.---Did you post the compression numbers ?

 

[oldboat1]

If you are finding mystery crap in the carbs, you have to clean them -- full treatment (soaking, poking, etc.) Almost sounds like parts of a wasp nest.

 

[jhotch]

compression is <a href="tel:125 120 120">125 120 120</a> .
From what I understand the hi speed jets would need to be smaller at high altitude? But It seems like the engine is starving for fuel , when I pump the bulb I can bring it out of the surge...? So if the jets are too big does that mean it is releasing fuel from the carb bowl too quickly for the fuel pump to keep up? (trying to reason this through). Would that also explain why my fuel mixture screws are a little less than 1 turn out to get a nice Idle? Appreciate the feedback, working hard to understand this system...

 

[jhotch]

And yes sir Oldboat 1 giving them the treatment tonight