How to make your 7900 or 681 NON rev-limited

[stihlboy]

OK, so it's doing 13600 in the cut?

Dude, Andre has the fastest 7900 i have ever seen

 

[AUSSIE1]

Dude, Andre has the fastest 7900 i have ever seen

Don't doubt that Andy's is a quick saw and running a limited module.

Gink's is no slouch.

What ignition module does Gink's run?

 

[grandpatractor]

I can see doing this for a racing saw,but for anything else I just don't see the point.:dunno:opcorn:

 

[AUSSIE1]

Andyshines 7900 can be heard bouncing off the limiter IN THE CUT!

Nope..........couldn't hear it reach the limiter in the cut, only out.

Certainly runs nice though.

 

[grandpatractor]

Nope..........couldn't hear it reach the limiter in the cut, only out.

Certainly runs nice though.

:agree2:
http://www.arboristsite.com/showthread.php?t=97883

 

[gink595]

Don't doubt that Andy's is a quick saw and running a limited module.

Gink's is no slouch.

What ignition module does Gink's run?

Mine is running a 066 coil

 

[PES+]

Mannnnnn

Now you did it........you went and painted a huge target on your back.


now it's all over but the screaming and crying when they ruin the coil pressing it off the laminates and back on the Dolmar frame.


CHI CHING........$$$$$$$$$$$$$$$$$$$$$$$$$$$
:stupid::stupid::stupid:

IT'S ALL THAT GUY BRADS FAULT.........


just kidding brad........good job

 

[gink595]

I can see doing this for a racing saw,but for anything else I just don't see the point.:dunno:opcorn:

Tuning is the only reason I wanted it and no other reason than that. I found the limiter made it a PITA to figure out if it was tuned right

 

[blsnelling]

Would it not be easier to tune the limited ignition module in the cut?
Would the ported saw exceed the maximum non limited range of the limited module in the cut?

That would net you the same performance gain, but would be harder to tune the timing IMHO. Cut times are much more subjective than tuning to the max RPMs on a tach. Also, I very much wanted the unlimited coil to aid in tuning, and being able to keep an ear on the tune.

No, Andy's 7900 is not turning over 13,500 in the cut.

 

[scotclayshooter]

No, Andy's 7900 is not turning over 13,500 in the cut.

Thats not what he was telling us!

 

[scotclayshooter]

Here's a video I made yesterday of me tuning the carb on my ported 7900, it should give you guys an idea how to tune the saw while cutting. I think I've got her set spot on for a firewood saw with a 24" b&c, I would however run it richer if was running a longer bar. At times you can hear the saw hitting the rev limiter really hard, a stock 7900 won't do that as easily.

Don't I look cool wearing shorts and chainsaw chaps.

<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/T3qykRe1j0g&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/T3qykRe1j0g&hl=en&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>

Hmm

 

[CanadianCarGuy]

Just a couple degrees in either direction will cost you nearly 1500 RPMs, throttle response, and power.


Brad, this is NOT accurate information. You will GAIN RPMs, throttle response AND power by advancing the flywheel counterclockwise. Advance it another 8 degrees or so and see for yourself. You might LIKE IT!

 

[AUSSIE1]

That would net you the same performance gain, but would be harder to tune the timing IMHO. Cut times are much more subjective than tuning to the max RPMs on a tach. Also, I very much wanted the unlimited coil to aid in tuning, and being able to keep an ear on the tune.

No, Andy's 7900 is not turning over 13,500 in the cut.

Thanks for that.

How much work to fit the 066 module Gink?

 

[Andyshine77]

Andyshines 7900 can be heard bouncing off the limiter IN THE CUT!.

Only with really light load, and or a bad chain will it hit the limiter in the cut.

 

[gink595]

Thanks for that.

How much work to fit the 066 module Gink?

I was being a jerk off, I'm using a 272 coil as well

 

[fredmc]

Mine is running a 066 coil

Mine has a 55 rancher coil. Is the 066 coil a bolt on without having to set the flywheel?


oops saw it too late

 

[AUSSIE1]

I was being a jerk off, I'm using a 272 coil as well

 

[tdi-rick]

Are you thinking of getting a Dolkita Al ?

BTW, can you send some of that cool weather up this way, another bloody dust storm today, I've been out in it and coughing up dust again...

 

[AUSSIE1]

Are you thinking of getting a Dolkita Al ?

BTW, can you send some of that cool weather up this way, another bloody dust storm today, I've been out in it and coughing up dust again...

Nah mate.
Not since the range has been covered by my 371/385.
The wife is cranky enough with the amount of barrels and pistons on the dinning room table as it is.
Not that I wouldn't own one and never say never I guess.

The weather has been lovely the last week and thank goodness for that as the boss wants the harvester parked up if the hydraulics go over 100 deg.
Anyway only one more week of that.
This rain has been beautiful.

 

[Andyshine77]

Hmm

Hi Scott. I was referring to WOT, in the wood it was mostly 4 stroking. It may have hit the limiter a bit because it wasn't under much load, but it was mostly 4 stroking..