OMC tach. setting?

[JB]

I have an OMC tach on a 1987 Johnny 48SPL.<br /><br />At first it read 2000rpm at idle. I took it out and examined the adjuster on the back. The little ring shaped sticker that shows you where to set it for various number of alternator poles is gone.<br /><br />After fiddling with the adjuster it I got it to read about 1000rpm at idle and about 3000rpm when I believe that it is turning more like 1500-2000rpm.<br /><br />Anyone got a pic of that sticker or a "how to find the right setting" suggestion?

 

[rickdb1boat]

Re: OMC tach. setting?

JB<br /><br />I believe that Tach has only 3 setting on it.(Correct me if I'm wrong). The first one(Fully counterclockwise position) would be 4 pole. The center position is 5 pole and fully clockwise is 6 pole, which is what you need. Hope this helps...

 

[JB]

Re: OMC tach. setting?

Thanks, Rick. <br /><br />Fully CW is where I have it now. Maybe my estimate of rpm on the muffs is off.

 

[rickdb1boat]

Re: OMC tach. setting?

I know when I run mine on muffs, I get high reading. No backpressure....