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Carbs on a 1975 Johnson 70HP

S

skerlock

New member
I'm use to Balancing Carbs on a Motorcycles using Vacum. Whats the trick on Boat motors. It seems like I have one that cuts out just coming out of idle . If I'm accelerating slowly or possibly a spark issue. I figure Id start with fuel delivery first.

Scott
 
Assuming that you have proper compression and spark on all cylinders.... 100+ psi and even.... spark jumps a 7/16" gap.

Throttle butterflies must just start to open when the scribe mark of the cam is dead center with the throttle cam roller, not before or after.

If you haven't cleaned the carburetors, do so. Manually clean the high speed jet located in the bottom center of the float chamber with a piece of single strand steel wire.
 
Compression is what I checked before I purchased with in 5 between all 3 About 110 - 115. I will check spark jump jump. Check TB's. I know the Carbs were gone through last year. Ill start looking. It runs good in all other positions. Thanks for the guidance.

Scott
 
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