Honda b75 K1 or K2, carb help.

[kalebsheridan]

Hey everyone,
I have a b75 Honda here (not a BF75) and I was wondering if anyone knows the procedure for adjusting the carb on this thing. It starts pretty easy but I use it as a trolling motor. After an hour or two of trolling, the spark plugs get super fouled and motor gets impossible to start again. I figured it's running too rich. I've cleaned the carb, but that's all you can do with these motors as you cannot get parts for them. Any help would be great. Just need it to work for a little bit more salmon fishing.

 

[MattFL]

Check the float height and that the float valves are sealing properly. If it was running properly for a long time then this problem suddenly started, it's not likely an "adjustment" issue, but more likely something is wrong. If a float is leaking (sinking), or the tab bent (if it's metal), or the float valve isn't sealing, it will run rich.

 

[kalebsheridan]

Hey matt, how would I check the float? I cleaned the carb but it has one of those sideways mounted float bowls so I wasnt sure about the correct position. I just didn't touch it to avoid throwing off any setting and blasted the float valve with cleaner and verified it wasn't stuck. I cannot attest to it's running condition in the past, I acquired this motor recently and I believe it was barely used, at least the carb was never cleaned due to the factory paint being pristine (by my analysis). I did however find a post on another forum outlining a procedure for adjusting the carbs on these particular motors, and after performing the adjustments, the motor runs beautifully. My guess the carb got dirty so instead of cleaning it, the last guy just enriched the mixture, as the pilot screw was 3 hole turns over from what I set as the more proper setting. I have yet to take it out trolling and truly see if my fix worked, but I will revisit this thread if it does not work.

 

[MattFL]

If it's new to you then that definitely adds unknowns. Hopefully your hunch is correct and all is good now, please let us know the result.

 

[km1125]

Adjusting the float is not nearly as critical as it seems to be. You really just want to make sure it's able to open and close the float valve fully. Doing it to spec insures that, but if you're paying attention when you're putting it together you can get there as well without a spec. If it's just a tad high or just a tad low it's not going to make any operational difference for the engine.