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Rebuild Carbs - Correct Bogging issue?? Johnson 135hp 1975

M

Michael Bergum

New member
Hello All!

I have a 1975 Johnson 135hp outboard (2 stroke)

I have good compression, engine will run strong from time to time.

Here is my issue:

It is incredibly hard to get started when it is cold. I will fight with it early in the morning to get it to startup before we head out for the day. Once it starts, I don't have any real problem out in the water. (Yes, I have meticulously studied all the starting procedures and experimented with several).

Lately it has gotten worse, now it also will "bog" and never get up to full RPM

Here is my question:

Has anyone had any real success in rebuilding the carbs on these? What else should I consider? I am looking to get some of this done over the winter.

Any thoughts?

Thanks!
 
Post your compression numbers.-------------Does spark jump an actual gap of 7/16" or more.---Report the results of that test.---------If stater / cables / batery is bad the motor will crank slow ( no spark ) and it will be hard to start---------
 
If the motor passes the above tests do a cylinder drop test on it to see if you can find a cylinder or two it's not running on.
 
Had the same issues with mine...same motor...make sure both carbs are fully closed at idle and the link and sync is set up correctly. That caused starting/idle headaches for me for a while. And the bogging if I advanced the throttle too slowly...slam it forward and it would take off..The jets are really easy to inspect/clean when the carbs are off. these carbs are really simple..not many moving parts or adjustments. Just make sure the high and low speed jets (2 on each carb) are clean. Turned out mine were clean as a pin and it was just the linkage setup holding the bottom carb open the tiniest bit. Surprising how much difference that made.
Of course make sure all the aforementioned checks are done - compression and spark. Without those good youll be chasin your tail...
 
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