checking small engine rpm?

Discussion in 'Mechanic and Repair' started by mowisme, Dec 15, 2012.

  1. mowisme

    mowisme LawnSite Senior Member
    Messages: 911

    Hi folks- I posted while back on differant issues on this GX620- and thanks to all the help it seems to be running great. I don't want to over-rev it but at same time want the max safe rpm. Is their any way I can check rpm without the crank exposed? Not sure what to buy or even how to hook up a electronic tach? Years ago I had a dwell meter..didn't they show rpm's? - my mind is fuzzy on this as I never had reason to check rpms before. Any thoughts on a tach from HF? Thanks again- Gene
  2. BigFish

    BigFish LawnSite Platinum Member
    Messages: 4,189

    Forget the dwell meter. HF sells a tach-DVOM for cheap. I have no idea how good it is, but if your only needin it this one time, why not.

    They make a Tiny Tach that's not too expensive, but I understand the knock-off versions aren't very accurate.

    Most mechanics nowadays use a good digital tachometer that you only have to get the unit near the plug wire for it to pick up a pulse. Some can be pricey.
  3. Oldtimer

    Oldtimer LawnSite Bronze Member
    Messages: 1,459

  4. BigFish

    BigFish LawnSite Platinum Member
    Messages: 4,189

    Yeah, and a pain in the a$$ to use!

    I got two of em, ya wanna buy one.......or both!




    Last edited: Dec 15, 2012
  5. ricky86

    ricky86 LawnSite Silver Member
    Messages: 2,135

    Those Vibra-tachs are incredibly accurate. Does require some practice, but far from difficult to use.
  6. BigFish

    BigFish LawnSite Platinum Member
    Messages: 4,189

    OK, I'll trade ya my TWO, count em, TWO treysits for your digital hand held tach!
  7. piston slapper

    piston slapper LawnSite Platinum Member
    Messages: 4,337

    He's serious....I am now the proud owner of a nice pair of Polish verneers...
    Formerly owned by the BigFish himself...only cost me a RATchete...circa 1857...
  8. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Messages: 2,249

    Here's what I've used since the mid 90's--tough to beat for the money. pet-1100 tach.htm

    I picked mine up at an Echo update where they were selling them for around $50 bucks as I recall. They are still available from Echo. About 3-4 months ago, mine would read 2X the actual rpms and I contemplated buying a new one. An Echo dealer quoted me $120, but a battery replacement took care of the problem. I have an Echo part number if anyone has an interest.
  9. BigFish

    BigFish LawnSite Platinum Member
    Messages: 4,189

    Yeah, I use a similar one from Oppama via Echo. Mine doesn't have all the buttons though.
    The dam thing is thin as could be and works great.
  10. BigFish

    BigFish LawnSite Platinum Member
    Messages: 4,189

    Mine is a PET 1000R Echo part # 99051130017.

    The PET 1100R is Echo part # 99051130018.

    They are the hot lick!

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