Tohatsu 25hp 1995. Rough idle and low speed.

[Hyatt]

I've just purchased this Tohatsu 25hp. It starts well, usually by the second pull and runs fine at mid to high speed but sounds like it's running on one cylinder at idle or low speed. I've changed the spark plugs so far and thinking about changing the coil and spark plug wires (they seem to be all one unit).
Any help would be appreciated. I've checked the archives with no luck.
Thanks,
Hyatt.

 

[Sea Rider]

Re: Tohatsu 25hp 1995. Rough idle and low speed.

Is it a 2 or 4 stroke horse ? Must check both Ignition Coils Output Ohms with needle tester separately if thinking that's the cause. Both must read same or near same. Probably carb's low gas circuit is not inmaculate clean producing described rough idle problems.

Happy Boating

 

[pvanv]

Re: Tohatsu 25hp 1995. Rough idle and low speed.

Year means nothing; Model is everything. Is this an M25C2 or C3? When was the carb last cleaned... Properly cleaned?

 

[Hyatt]

Re: Tohatsu 25hp 1995. Rough idle and low speed.

Year means nothing; Model is everything. Is this an M25C2 or C3? When was the carb last cleaned... Properly cleaned?

The model is m25c2. I don't know when the carb was last cleaned. I played with mixture screw yesterday and it ran better but still not right.
Whats the best way to clean the carb? Is there a cleaner that I could dip it into and let soak?
Thanks for your help.

 

[Hyatt]

Re: Tohatsu 25hp 1995. Rough idle and low speed.

Is it a 2 or 4 stroke horse ? Must check both Ignition Coils Output Ohms with needle tester separately if thinking that's the cause. Both must read same or near same. Probably carb's low gas circuit is not inmaculate clean producing described rough idle problems.

Happy Boating

This motor is a 2 stroke. Your probably right about the carb, I adjusted the mixture screw yesterday and it was better but still not great.
Thanks for your help.

 

[pvanv]

Re: Tohatsu 25hp 1995. Rough idle and low speed.

Sounds like you may need a good carb cleaning. Assuming everything else with ignition, etc., checks out, the carb work is as follows:

Removal and Complete disassembly (including jets and emulsion tube nozzle).
Submersion of all non-rubber parts in real carb dip for about 4 hours at room temp.
Blow out of all passages with generic carb spray.
Careful reassembly, paying attention to float height.

If there is wear to rubber parts, etc., install a carb kit during reassembly.

 

[Hyatt]

Re: Tohatsu 25hp 1995. Rough idle and low speed.

Thanks Paul, I'll try to get at this today. Let you know what happens.
Roly.