Tach squirrely

[roach]

Have 1997 90hp non-oil injected. When taken out recently tach reads
maybe 6000-7000 rpms but is probably around 2000-3000 rpms actually.
It's running perfectly normal. Than it returns to 2000-3000 rpms on the
tach. May read normal for awhile than starts running higher again. I
know the props not slippng. Motor seems to run just fine. Tach reading
never goes lower than what the motor actually running. Or should I say
reads low at all.
The time out prior to this the starter battery went dead on the water
and restarted with trolling motor batteries. Had starter battery tested
checked out good. Thought I may have had to many accessories on.
Also this has an OEM System Check analog tach.

Thanks for the help,
Roach

 

[ineedacottage]

Re: Tach squirrely

Have 1997 90hp non-oil injected. When taken out recently tach reads
maybe 6000-7000 rpms but is probably around 2000-3000 rpms actually.
It's running perfectly normal. Than it returns to 2000-3000 rpms on the
tach. May read normal for awhile than starts running higher again. I
know the props not slippng. Motor seems to run just fine. Tach reading
never goes lower than what the motor actually running. Or should I say
reads low at all.
The time out prior to this the starter battery went dead on the water
and restarted with trolling motor batteries. Had starter battery tested
checked out good. Thought I may have had to many accessories on.
Also this has an OEM System Check analog tach.

Thanks for the help,
Roach

Hey Roach,

I am no expert, but I was having trouble with my tach as well. Check out this thread...it may have some helpful information.

Thanks.

 

[Silvertip]

Re: Tach squirrely

There is a dial on the back of the tach that allows setting the number alternator poles. Move that dial to various settings several times and then put it back to 6P. Sometimes they get a little gunked up and become intermittent. Rotating the dial cleans it up and things return to normal.