Quick question regarding tachs and rev-limited coils

[KingDavey]

Looking for experience. Will tachometers always register crazy numbers when a saw, or any 2-stroke for that matter, with a rpm limited coil is overrun? Or can/will they show what the saw has been bounced down to? Just curious...

 

[watsonr]

Mine shows crazy numbers when it hits the limiter. Tune the saw in wood and you won't have a problem.....
like this

http://www.arboristsite.com/chainsaw/147465.htm

 

[jus2fat]

Chain saw limiters aren't exact.

Soo they usually go above the limit then kick in and stall the saw down..

Thus you can get really wild readings..that's why tuners hate limited coils..!!

Will they always do this..NO..every limited coil is not the same as the next.

That's why it's confusing and upgrade builders go to unlimited coils right away..!!

J2F

 

[KingDavey]

So has anybody seen a limited coil on a piece of equipment read low rpms on a tach when it was actually over-revving?

 

[jus2fat]

So has anybody seen a limited coil on a piece of equipment read low rpms on a tach when it was actually over-revving?

I have never heard of it happening...at least with a decent professional tach.

With lower priced tachs..I would guess anything is possible..!!

J2F

 

[KingDavey]

Good info!!!!

 

[Termite]

So has anybody seen a limited coil on a piece of equipment read low rpms on a tach when it was actually over-revving?

I think I experienced what you described this past Saturday. It was on a 7900.
I checked the [email protected]. Tried to lean it out just a little and got ~11K.
So, I took the saw to a log and tuned it in the wood then returned it to the logger and didn't think any more about it. I think I have a good tach.