Old Craftsman Dwell/Tach on 94ish Rude 90

[Levinz11]

Hey guys quick question. I have a very old Craftsman Dwell/Tach for cars or my old OMC 4.3. My buddy has a mid 90's Evinrude 90 crossflow 4cyl outboard. We have been doing a lot of work on her and want to set idle in the water today.

My understanding (not having the boat in front of me) is that this motor has a 12 pole stator, putting out 6 pulses per revolution.

I am thinkning that connecting the tach to either the remote or the stator...setting the tach to the 6cyl mode (3 pulses per rev)....and dividing that number by 2 (halving it) will give us an accurate reading.

What do you say? Will this work?

Thanks.

 

[boobie]

Re: Old Craftsman Dwell/Tach on 94ish Rude 90

Normally the tach in a boat runs off of the stator AC impulses. Try it and see what happens.

 

[kodibass]

Re: Old Craftsman Dwell/Tach on 94ish Rude 90

They sell laser tach's with sensor tape delivered to your door for $15.00 put the sensor tape on the flywheel & set rpm's they work on anything that rotates from 2.5 rpm up to 90.000-------------however I think your method most likely will work

 

[orbanp]

Re: Old Craftsman Dwell/Tach on 94ish Rude 90

They sell laser tach's with sensor tape delivered to your door for $15.00 ...

Do you have a link?
I have seen ones for a lot more than $15.00, though I have not looked that hard.

Thanks, Peter

 

[Levinz11]

Re: Old Craftsman Dwell/Tach on 94ish Rude 90

Digital Photo Laser Tachometer Non Contact Tach: Amazon.com: Industrial & Scientific

 

[orbanp]

Re: Old Craftsman Dwell/Tach on 94ish Rude 90

Thanks for the link!
The Canadian amazon site sells the same tachometer for C$30.00, and it was recently lowered from C$50.00.
Considering that the dollars are roughly at parity that is quite a deal ;-)

Thanks, Peter

 

[kodibass]

Re: Old Craftsman Dwell/Tach on 94ish Rude 90

Harborfreight.com has them also