prestolite electronic conversion and origional omc points type tach conflict

barnstormerj

Seaman Apprentice
Joined
Jun 13, 2011
Messages
33
Just changed my omc distributor from points to the prestolite conversion . Now have trouble with the tach signal being for points, it bounces around a lot at low rpm. I am sure someone has had this issue. i purchased a 8910 b tach adapter product, that i was told would work, but the problem is , it references the msd igition module, and nothing else. I have found spotty information in using a resistor in the tach wire, but do not know. Hey the boat runs great, never so good~Hope someone that know of a tach solution will post , thanks Jack
 

inthedirtagain

Petty Officer 1st Class
Joined
Aug 10, 2011
Messages
321
I think that this is common in a points-to-magneto conversion. I say this because I've converted two different classic mustangs running the original 289 V8 with points and non-factory tach. Each time, I had a slight tach bounce when at idle. All I can say is to make sure you contacts on the coil are clean.
 
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