Mastermind meets the Dolmar 7900

[Buffhunter]

Derail away.

I just hope you figure out what has been killing your saws. What nmurph said about the limited coil is what my money's on. I just ran a stock one that was bouncing off of the limiter badly.

I'm almost done with the first 7900 with two more to go. Everything that could happen to slow a day up has happened here today. My wife's van took a crap, local guys have been in and out all day, the phone has been ringing off the hook.............I'll get done someday.

Man don't these people know you have a 562 waiting to be molested?????? The nerve of some people. LOL

 

[cutmaster]

I'm not sure if this is a red flag or not....Are you mixing the whole 55 gallons all at once? Is this a common thing to do? What is the chance of the oil settling over time or not being mixed thoroughly with the gas? Where are you in located in MN?

Not a chance, I'm 11 miles north of mora, fuel is at the raceway in princeton 33 miles 1 way, we fill 16 gallons of fuel add 1 gallon oil and add 32 gallons of fuel, sloshes back and forth - bouncing up and down these crappy old logging roads in the back of an F550 with a liftgate for 33 miles, the drum has to sit for at least 8 hours prior to opening unless you want to get covered in fuel..... smells good for sure, eyes water and all that good stuff.

 

[cutmaster]

Even in the right colors

Ok that's it, that's it, i've had all I can take, there's only so much a guy can take and this is way over the line!

I'm going to have to Buy a bunch of Stihl saws and have you work your magic on them Brad!
So tell your wife you'll see her again sometime this summer!:hmm3grin2orange:

 

[nmurph]

Even in the right colors

Your car matches your motorcycle

 

[Ductape]

At least he chose the Pacer X....... the *cough, cough* performance version. :cool2:

 

[Hedgerow]

At least he chose the Pacer X....... the *cough, cough* performance version. :cool2:

Hmmm... The pacer that outruns the corvette...
Just sayin...:msp_sneaky:

 

[nmurph]

Cut, I understand what you were trying to accomplish by cutting the saw off in mid cut. But the tach is reading the RPM at the time the time the coil fires the last revolution or two. The saw may have already bumped the limiter and been on its way down when you pulled the plug and got the reading. Another thing to remember is that reading the plug is not an exact science, and most people make the mistake of looking at the area around the electrode.
I slowly adjust mine up against the limiter as seen on the tach. Then I back off a 1/8 turn or so and check it in the wood at Brad mentioned, listing for four-stroking and cleaning up in the cut.

 

[Jacob J.]

At least he chose the Pacer X....... the *cough, cough* performance version. :cool2:

A good friend of our family had the Pacer X, but his was the silver and blue one. He had the open hatchback too. Five of us loaded up in that thing
for a road trip. I was six and I spent the entire time in the hatchback. A 26-hour drive to South Dakota.

 

[parrisw]

The only way to tune a limited ignition is in the wood, IMHO.

I'll buy one of your blown up 7900's.

 

[blsnelling]

Your car matches your motorcycle

Believe it or not, I thought about posting that pic

 

[cutmaster]

Cut, I understand what you were trying to accomplish by cutting the saw off in mid cut. But the tach is reading the RPM at the time the time the coil fires the last revolution or two. The saw may have already bumped the limiter and been on its way down when you pulled the plug and got the reading. Another thing to remember is that reading the plug is not an exact science, and most people make the mistake of looking at the area around the electrode.
I slowly adjust mine up against the limiter as seen on the tach. Then I back off a 1/8 turn or so and check it in the wood at Brad mentioned, listing for four-stroking and cleaning up in the cut.

Ok, I get all that,
what I don't get is " in the wood " tuning, how much pressure vs what rpm stuff.
Off the top of my head I believe the manual says 9500 RPM ( in the wood I would think )
but, at what pressure on the saw? I mean I can dig the dawgs in and have the saw turn 9500 RPM, but I know it will blow up on a lighter cut. So are we talking 9500 RPM in the wood with say no pressure on the saw?

 

[blsnelling]

Forget actual RPM numbers here. Your simply listening for the saw to 4-stroke when you let off in the cut, and then instantly clean back up once put back under load. I have a thread somewhere that demostrates this. There are others as well. Matter of fact, my bud Andyshine77 demos it with a 7900. Maybe someone will have a link.

 

[cutmaster]

The only way to tune a limited ignition is in the wood, IMHO.

I'll buy one of your blown up 7900's.

parrisw,
I'll sell you one but I have to warn you; Dolmar 7900's will flip you right over the top of a large tree laying on the ground such as the tree in your pic, I've had such good luck with these bad boys using any other saw is like cutting trees with a hack saw! So get your wallet out!
No really, I don't know what in the world is going on with all of mine, all of them are 2008 models.
Don't know if that is my issue or what......
By 2008 being an issue I am saying they had been sitting brand new in a warehouse for years, not that 2008 was a bad year...

 

[cutmaster]

Forget actual RPM numbers here. Your simply listening for the saw to 4-stroke when you let off in the cut, and then instantly clean back up once put back under load. I have a thread somewhere that demostrates this. There are others as well. Matter of fact, my bud Andyshine77 demos it with a 7900. Maybe someone will have a link.

Ah ha! now I see said the blind man as he picked up his hammer and saw!
I get what you are saying now Brad!
Q; why would tuning a Husky the way I have for all this time be fine, yet I have problems with my 7900's? Touchy carbs? hearing loss on my part?? :msp_confused:

 

[Axlerod74]

I am still trying to get a feel for this technique. Sorry, don't mean to take away from the OP.......:msp_rolleyes:

http://www.arboristsite.com/chainsaw/154314.htm

 

[Mastermind]

Pics....

 

[blsnelling]

Here's the vid I mentioned.

<iframe width="640" height="480" src="http://www.youtube.com/embed/5BZkB9QQTJU?rel=0" frameborder="0" allowfullscreen></iframe>

 

[blsnelling]

Pics....

I've got a hunch you've built a runner I like what I see!

 

[parrisw]

parrisw,
I'll sell you one but I have to warn you; Dolmar 7900's will flip you right over the top of a large tree laying on the ground such as the tree in your pic, I've had such good luck with these bad boys using any other saw is like cutting trees with a hack saw! So get your wallet out!
No really, I don't know what in the world is going on with all of mine, all of them are 2008 models.
Don't know if that is my issue or what......
By 2008 being an issue I am saying they had been sitting brand new in a warehouse for years, not that 2008 was a bad year...

I'll be ok. :msp_biggrin: PM sent.

Will

 

[parrisw]

Randy. Looking good. Any numbers for us junky's.