Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

Sign in to follow this  
mech123

onan rpms

Recommended Posts

mech123

im trying to set top no load on my powermax... I used 2 different tacs, tiny tacs and read 4950 or so.... engine does not sound like its running that fast... I used a vibr tac and reading is about 2700 rpms.... which reading do I use??? does the 12 volt coil and point interrupt the electrical tac readings????

Share this post


Link to post
Share on other sites
BLT
quote:Originally posted by 720nut

Hey Bob where do you get one of those, looks to be pretty neatdOd


id="quote">
id="quote">I don't have the Tiny Tach but the $18- variety they say good for 36000 hours or 4 years. Mine is still ticking after three years, E-bay or Amazon.

Share this post


Link to post
Share on other sites
mech123

I was talking with a guy about this rpms issue. He use an rpm tac on his model Rc airplanes. Put a piece of tape on 1prop blade and use the tac. This read the true crankshaft rpm. He said the kit is about 25$ at a hobby shop...another old time car mechanic said his tac has to be set per number of cylinders on vehicle

Share this post


Link to post
Share on other sites
Kenh

The "RC" tach, if it is like mine, is an optical tach. It reads the contrast of light and dark. You will need two pieces of tape to get a true reading. I would suggest wrapping the crank with black tape and placing two white stripes on the tape and a bright light for the best reading. It's possible it MIGHT read the keyway but I doubt it would. One piece of tape will require doubling the reading. Mine is very accurate. The vibrtach is a good piece of equipment. That should be as accurate as you need.

Ken

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

  • Who's Online (See full list)

    • RenegadeJ
    • R. McGee
    • Talntedmrgreen
    • Rvcjacobsen
  • Today's Birthdays

    1. Big 10
      Big 10
      (71 years old)
    2. cowfan
      cowfan
      (51 years old)
    3. dynodave
      dynodave
      (71 years old)
    4. WaylandLegacy
      WaylandLegacy
      (44 years old)
  • Recent Status Updates

    • SonOfCreepfeed

      SonOfCreepfeed

      Thinkin' about this old girl.

      · 2 replies
    • Dean McFadden

      Dean McFadden

      Good morning peeps! I’m always searching for helpful information with my AC collection. Hope to find out new information and pass on my own experience in restoration. Here are some pics of my babies. I’m still looking for front rims for the 410 so yesterday I put the 310 wheels on took it for a drive. Working pretty good but still needs some carb work. Gotta get the 310 running next. Have a great day!😁
       

      · 1 reply
  • Adverts

×