carb tuning 4hp tohatau

[xluke]

Hello, I was wondering if anyone can provide some tips.on tuning my tohatsu carb. Lately, it has been stalling at low rpms but otherwise runs well except it briefly loses some power at 3/4 throttle. I have tried increasing the idle speed but to get the idle fast enough so it doesn't stall results in it being too fast for safe shipping. Any tips or instructions greatly appreciated

Thanks!

 

[pvanv]

Re: carb tuning 4hp tohatau

Assuming your model is MFS4 (either A2 or B). You will undoubtedly find that the carb needs a full complete disassembly and a 4-hour soak in carb dip. This is due to varnishing from a combination of not running the carb dry every day, and the junk gas we get today. There is no provision to adjust idle mixture thanks to EPA regulations.

 

[xluke]

Re: carb tuning 4hp tohatau

This was easier to fix with patience in the end. First, I added a fair amount (about 3oz to 3gallons) of seafoam to my fuel. Then, when turning off the engine at the end of the day I would disconnect the fuel line and let it run completely dry (adjusting the carb as necesssary to keep it running as long as possible). After about 5-10 outtings it started idling perfectly. After about 15 outings I noticed it was running like-new again with excellent throttle.

No doubt it was a dirty carb, but this saved some hassle!

Thanks!