tohatsu 30 four stroke idle speed

[pogyman]

I have a brand new 30 and the factory set idle is 1800 rpm. It should be 850rpm. This is an efi model. I plan to get the service manual but haven't yet.
The throttle cable is not causing this, I disconnected it and no change. Is idle adjustment a simple matter?

 

[TOHATSU GURU]

Re: tohatsu 30 four stroke idle speed

Since it is "brand new" you need to take it into a Nissan or Tohatsu dealer for warranty service. They will then determine if the problem is the tachometer, the settings on the engine or the ECM.

 

[pvanv]

Re: tohatsu 30 four stroke idle speed

TG is right. There is a strong possibility that your tach is setup wrong, reading double the actual RPMs.

 

[pogyman]

Re: tohatsu 30 four stroke idle speed

Thanks for your responses. I checked the tach that was supplied with the engine with one of those inductive tachs that a friend lent me. They read the same. I also have access to one of those laser/optical tachs and I will check it with that tomorow. Either way I'll be talking to my dealer. I'm just trying to gather as much useful information as I can first.

 

[pvanv]

Re: tohatsu 30 four stroke idle speed

The correct tach pole setting for these motors is "12-pole". Keep in mind that while this is a 4-stroke... it fires on every upstroke of the piston (similar to a 2-stroke). That is... it fires on exhaust as well as compression. One spark per revolution... Not one spark per 2 revolutions, as a 4-stroke car would.

 

[pogyman]

Re: tohatsu 30 four stroke idle speed

Problem solved. The tach was on the 6 pole setting. Now I need to play with prop pitch. WOT is 5300 rpm with a 10X13 so I'm thinking a 10X11 to bring rpm up 600 to 800 rpm or maybe a 10X10? WOT on this engine is supposed to be 6250 rpm. This boat was originally set up with a Johnson 35 , 1978 spinning a 10.5 X11. It's a Simmon's Sea Skiff that I built in 1994.