Help! Tach problems

RABBITFISH · #1 09-01-2015, 08:34 PM

I am at a loss, I have been searching all over the internet and the forums and have not found an answer to my problem. I was hoping someone would recognize this and give me a lead as to how to trouble shoot it. Here is my dilemma, 2001 Yamaha 225 OX66. The digital tach is not functioning correctly. When I turn on the key, it does not go to zero, but hesitates, then a faint 1 comes up, while running the segments seem to jump all around without giving any clear numbers. The motor seems to run fine without any problems. I have checked all of the under dash connections, all seems to be good and read the proper 12 volts when ignition is on. Tried running a different ground to it but it made no difference in the problem. The gauge works for the trim signal and the oil level indicator, and the back-light works correctly. Any ideas on where to look next? I suspect perhaps somewhere under the cover of the motor but not sure exactly where to look. Any thoughts would help. It has been working fine for the entire time I have had this motor. The only work I have done lately was to change out the low pressure fuel pumps. Maybe I loosened a connection somewhere?

phatdaddy · #2 09-02-2015, 05:39 AM

no real knowledge of this motor, but anytime i had tach troubles, it was the stator. i'd check the charging system. if it's putting out 13.5-14.5 volts, then probably a goofy tach.

hang in there, someone who really knows will be along...

spareparts · #3 09-02-2015, 07:43 AM

check teh charging system, if its charging, try hooking up a standard tach. I keep one laying around with pigtail leads and clips for just this reason. IF a standard tach works, then your digital tack is bad

THEFERMANATOR · #4 09-02-2015, 10:25 AM

Not sure on the OX66, but earlier carbed engines had a seperate pickup for the digital tach. My 93 250 parts engine had a seperate tach pickup mounted that read off of the flywheel I bleieve. It had a seperate crank trigger under the flywheel, but had a magenetic pickup on the outside of it for the tach(at least thats what I was told it was for). I believe it was only for the digital tachs.

RABBITFISH · #5 09-03-2015, 11:32 AM

Thanks so much for all the advice. I did have an old tach from a car that I hooked up and it worked fine. The charging system is working properly, so it looks like I will need to get a new tach. Anybody have one for me that won't cost an arm and a leg? I have looked at the prices on amazon and ebay, not to mention yamaha outboard parts, but not sure if I want to sink that much into it.
Another question, will the malfunctioning tach affect the performance of the motor if I want to take it out fishing?

THEFERMANATOR · #6 09-03-2015, 03:36 PM

Shouldn't hurt anything, just annoying.