Bowtie
Gearhead
I was looking for an unlimited coil for a Dolmar 6400 that has a 7900 to end on it. The 272 coil part number I looked showed 5036202-03. Anyone know if this is the coil I need for this conversion?
272 coil conversion to Dolmar 7900
- Thread starter Bowtie
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Bowtie
Gearhead
If this is right, it shows that it fits a bunch of different husky saws. Have I missed something here?
bookerdog
The New Champ
Romeo would be the one to ask this. But I think the 272 is just right.
Bowtie
Gearhead
OK, thanks for the reply. I am curious on this, as the person selling this coil says it fits 50 51 55 254 257 261 262 61 268 272 Husqvarna saw.
The 272 coil is the same on several saws. A search of the 1999 database shows that coil fitting the 268, 272, and 61.
I am fairly certain that it's not just a bolt-on coil. Modifications have to be made to the saw and the coil for it to work. Seem I recall that a new keyway had to be milled into the flywheel to change the ignition timing for use with the new coil. I went through that when I was trying to decide between the 7900 and the 372 for modding. The coil issue was one of the reasons I chose the 372.
Ian
Ian
Bowtie
Gearhead
Thanks for the info guys. I tried this 7900 for real today in Chinese elm Im taking down in my back yard. It has 20" skip round chisel carlton chain on it. I am a Stihl person, but I have to honestly say this 7900 would put the smack down on the 441 I traded for it. Thats with skip chain, so its not really fair. With full comp it would probably be sad what the Dolmar would do to the 441.
Pros: POWER POWER POWER, inboard clutch, weight isnt too bad
Cons: The dawgs are stupid and useless, The stop switch already fell apart and I had to put it back together, the clutch takes a different tool to remove it, but I can make that. The top cover is a pain in the rear to get on and off, but I will get used to it. Finally, i dont like the rev limiting coil.
Overall i think I will like this saw, did I mention it has a ton of power? The transfer ports have been modified and polished. The intake and exhaust ports have also been cleaned up and it has a muffler mod.
Pros: POWER POWER POWER, inboard clutch, weight isnt too bad
Cons: The dawgs are stupid and useless, The stop switch already fell apart and I had to put it back together, the clutch takes a different tool to remove it, but I can make that. The top cover is a pain in the rear to get on and off, but I will get used to it. Finally, i dont like the rev limiting coil.
Overall i think I will like this saw, did I mention it has a ton of power? The transfer ports have been modified and polished. The intake and exhaust ports have also been cleaned up and it has a muffler mod.
redprospector
Addicted to ArboristSite
The dog's on the 7900 are just right for our wood, but I guess on a 20" bar they'd eat up a lot of bar length.
Sound's like if you remove the dog's, & replace the switch you'll be in good shape.
Glad you like your new saw,
Andy
Sound's like if you remove the dog's, & replace the switch you'll be in good shape.
Glad you like your new saw,
Andy
romeo
Addicted to ArboristSite
YES
You will have to mod the mount a little. Make sure you end up with .010 air gap.
Mark your flywheel while the old coil is in it and put a timing light on it. Mark it to the case where you are hitting at 12k. Leave your marks on it, swap the coil and run it back up to 12k on your tach. Hit it with the timing light again, that will tell you how far to index your flywheel to get it timed back right.
Bowtie
Gearhead
Ok, will that involve milling a new flywheel keyway for the new coil?
Lakeside53
Stihl Wrenching
lololol keyways are for wimps..
So.... how does it run against the OLD 064?
So.... how does it run against the OLD 064?
Bowtie
Gearhead
It held its own with Carlton skip chain, I dont have a loop of Stihl full comp to try against it...yet. I think it will be close. That 7900 has nuts. The 064 was running 20" .63 rsc chain. I will post back and give a more accurate description when I have comparable chains. The 064 will be needed with the 28" tomorrow to drop the trunk of this old diseased elm Im taking down in my back yard.
Bowtie
Gearhead
So you saying Lakeside I dont need to worry about adding a keyway, just get the timing right with a different coil and run it?
Four Paws
Addicted to ArboristSite
The keyway is just a tool for easy, repeatable set-up at the factory. The key does nothing more than align the flywheel, the taper on the shaft is what holds the flywheel in place.
Make sure you mark things like Romeo said...
Make sure you mark things like Romeo said...
Lakeside53
Stihl Wrenching
yes... and be careful that the flywheel doesn't slip when you tighten the nut. MARK IT before tightening.,., and SET the flywheel onto the taper with a socket and a sharp tap from brass hammer... degrease the flywheel and taper perfectly...
Be accurate. Even 1 degree makes a big difference, and too much advance will eat your piston... and wallet.
Why change the coil anyhow? unless you want more WOT rpm (?????), just tune it correctly with the limited coil..
Be accurate. Even 1 degree makes a big difference, and too much advance will eat your piston... and wallet.
Why change the coil anyhow? unless you want more WOT rpm (?????), just tune it correctly with the limited coil..
You mean you can't use a fat sharpie to mark your flywheel position? 
Ian
Ian
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PES+
Addicted to ArboristSite
Well sure you can
As long as you don't hit anything with a hammer.......except the flywheel.....and the flywheel knock off tool.......and the...................................
Mark it with a wide marker and scribe a line in the mark
Me?......I don't hit flywheels with any metal hammer.....but that is just me
As long as you don't hit anything with a hammer.......except the flywheel.....and the flywheel knock off tool.......and the...................................
Mark it with a wide marker and scribe a line in the mark
Me?......I don't hit flywheels with any metal hammer.....but that is just me
Crofter
Addicted to ArboristSite
Lake didnt say to Hit anything but the deep socket with the hammer, Lol!
"and SET the flywheel onto the taper with a socket and a sharp tap from brass hammer.".
The degreasing of both shaft and bore is key to the issue.
PES+
Addicted to ArboristSite
Yah....I know......dang cyber game wardens.....hows a guy supposed to kiwi fish......
If I do seat a taper I use a brass cylinder that is bored and only hit it with a dead blow.
Lapping of the fit to ensure full engagement of the taper is as important as degreasing in my experience
*cyber chums for spanish mac lovers*
If I do seat a taper I use a brass cylinder that is bored and only hit it with a dead blow.
Lapping of the fit to ensure full engagement of the taper is as important as degreasing in my experience
*cyber chums for spanish mac lovers*
Bowtie
Gearhead
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. ....
