272 coil conversion to Dolmar 7900

[HUSKYMAN]

Not only is the skip chain bad, but that round chisel is holding the saw back too. A 24" bar and full comp chisel should fit the saw real nice, and let you keep the big dawgs.

Not only did you trade a Stihl for a Dolmar, but now you are putting Husky parts on it lol. See there is more out there than just Stihl. Good luck

 

[Bowtie]

Not only is the skip chain bad, but that round chisel is holding the saw back too. A 24" bar and full comp chisel should fit the saw real nice, and let you keep the big dawgs.

Not only did you trade a Stihl for a Dolmar, but now you are putting Husky parts on it lol. See there is more out there than just Stihl. Good luck

LOL, it came with a 20" Jonsered bar (made by Windsor).

 

[Lakeside53]

Excellent information. Now when i get the coil for it are one of you guys going to come to my garage and show me just how to do all that right? I'll buy the beer. ....

You still haven't told us why you want to do it...

 

[Bowtie]

Right, I cant wait to try some full comp RSC chain on it. Going to try to fine a 24" bar in time, gotta get the rest of the toys I been buying paid for first. May try the 20" RSC first. I know square cuts faster, but until I get a setup to sharpen it right, I will have to stick with round chisel.

 

[Bowtie]

You still haven't told us why you want to do it...

I feel like the powerband would let the saw perform better above the rev limiter set speed. I know Im running full skip 20" setup, but even pushing on the bar deep in the cut it acted like it was bouncing off the limiter. Keep in mind it isnt quite stock.

 

[Lakeside53]

nope.... If you are using power band at the limiter, you need a more agressive chain, more cutters, bigger wood, or a smaller saw... and the "power band" declines well before the limiter.

If you are going to mod the cylinder, maybe....


In my limited experience, the limiters just complicate newbie tuning... not limit power. if you're just playing, GO FOR IT (with care).

 

[oldsaw]

I feel like the powerband would let the saw perform better above the rev limiter set speed. I know Im running full skip 20" setup, but even pushing on the bar deep in the cut it acted like it was bouncing off the limiter. Keep in mind it isnt quite stock.

Step up a tooth on the sprocket. Lake is right, the power band has long passed by the time the rev limiter is hit on a stock saw. Ported, could be a different story.

Mark

 

[bwalker]

Step up a tooth on the sprocket. Lake is right, the power band has long passed by the time the rev limiter is hit on a stock saw. Ported, could be a different story.

I was surprised to find my mildly woods ported 372 pulls 13,000 rpm in the wood. This was with a 16" bar, 72 LG cutting sugar maple. I would suspect a ported 7900 would be banging the rev limiter.
Not to mention the fact that non limited coil makes tuning easier...

 

[Bowtie]

Im running an 8 tooth sprocket now. The guy I traded had done some transfer port work on one side. I matched the other side to it carefully. He had also done some smoothing and polishing on the intake. I widened the exhaust port slightly and put the piston and cylinder for the 7900 on. The muffler mod that was done when i got it opened the muffler up quite a bit. Im going to do some cuts and check with the tach in the cut to get a better idea on what rpms Im hitting. You may be right, I might not need a non limiting coil. The tach test will tell. If Im NOT hitting the limiter with skip and 20", I should be ok with full comp. A smaller saw, nope, already have smaller, I like the bigger cube saws, way fun!!

 

[Bowtie]

Ok I buried the bar in green chinese elm after adjusting high idle for todays 50 degree drizzly weather. The highest reading I got with the bar buried was 13,100. That was max reading on the tach during the cut. Average rpm was around 12500. I may not have had the carb adjusted right, as I had to lean it quite a bit to achieve rev limiter rpm. Then I backed it out to where it was just below the limiter. What surprises me is the it hit 14000 before it started jumping all over the place. Isnt the rev limiter supposed to kick in at 13500?

 

[Lakeside53]

It's not a precise as you may think... plus/minus a few hundred easily, maybe more.

I'd leave your coil alone and play with the rest of the stuff..

Your max HP is much lower down, so although it might be fun at high rpm, it's not the most effcient place to cut. If you can "bury" a decent length bar in the wood and it's still 13k, you need bigger wood... (or smaller saw )

 

[Bowtie]

It's not a precise as you may think... plus/minus a few hundred easily, maybe more.

I'd leave your coil alone and play with the rest of the stuff..

Im gonna take your advice Andy. I am still curious as to the coil swap, thanks to everyone that posted. I think I had the carb adjusted wrong, possibly thats why I thought it was hitting the limiter. After adjusting and checking with tach, it really sounded like it was hitting it. Just shows I am a newbie at the rev limiting coil adjusting. Im glad you put a non limiting coil on the 064 Andy!

 

[Lakeside53]

. Im glad you put a non limiting coil on the 064 Andy!

I figured it was a minor inconvenience me, and might have saved a saw getting cooked by all you incessant carb screw fiddlers!.. It might surprise you, but I rarely touch my carb screws year to year.... set slightly on the rich side and forget them.

 

[Bowtie]

Point taken. I notice a difference when there is a big temperature and humidity change, mostly with idle speed and acceleration coming off idle. I havent touched the 361 since I initially set it. The 026 i have tweaked the idle a little bit, but not the High since the muffler mod. The 7900 was unfired and never set when I got it, my first experience like that, but you all helped me with that.

 

[Urbicide]

I had asked Gregg Grande about the possibility of an after market unlimited ignition module for the Dolmars. He said Bailey's would have to order a minimum of 1000 pieces from their supplier. I would take 3. Anyone else want to speak up for the other 997?

 

[romeo]

I had asked Gregg Grande about the possibility of an after market unlimited ignition module for the Dolmars. He said Bailey's would have to order a minimum of 1000 pieces from their supplier. I would take 3. Anyone else want to speak up for the other 997?

Well I would take three more of them, only 994 to goopcorn:

 

[scotclayshooter]

Well I would take three more of them, only 994 to goopcorn:

Make it 992 me and im sure TreeBeard would take 1 each

 

[Lakeside53]

but... 996 of you you don't need them... it's not hard to tune with the factory coil...opcorn:

 

[Jacob J.]

LoL Andy, you're fighting the good fight.

 

[Bowtie]

I would buy one, if for nothing else to have spare parts. If Andy says it not necessary I take his word, but I bet IF Baileys did decide to sell a coil that was unlimited, I think they would do ok on it. But Im no marketing guru. I do kow that I would buy one.