'71 Johnson 50 - How can you tell RPM

[mplaydon]

I have read alot about how many RMP's your OB should be doing at idle and at top speed...so on and so forth. My question is, how can you tell??<br />I have a 1971 Johnson 50 (50ESL71S) and I don't have a rev counter or anything. Is it possible to fit one? Where would I get such a thing? Also while we are on the subject I was also thinking of fitting a Speedometer...can these be retro fitted if so how do they work? Sorry for all the questions but I am still finding my sea legs as it were.

 

[DJ]

Re: '71 Johnson 50 - How can you tell RPM

TZ,<br /><br />Tachometers are avialble right here on the iboats Mega Mall site. See following website.<br /><br />Forget the speedometer. They are notoriously inaccurate in boats. Buy a cheap GPS instead.<br /><br /> http://www.iboats.com/mall/index.cgi?cart_id=682771763&keywords=tachometer&submit=Search

 

[mplaydon]

Re: '71 Johnson 50 - How can you tell RPM

That's great. Any idea how these are connected and callibrated. Is it explained in the manual or in the instructions that come with the unit?

 

[Mucka29]

Re: '71 Johnson 50 - How can you tell RPM

i got two words, a tiny tach