So who has modded there Dolmar 7900??

[Stihl Crazy]

I set my modifed 7900 to 13,300 on the tach and then went 1/8 turn leaner. My 5100 was set to 14,400 then 1/4 turn leaner. My old 064 was governed the same way as the 7900. The shop manual for it said to set at 13,000 ( by tach) then turn the high 1/2 turn leaner. Ran the old saw that way all the while I had it. No problem with the Stihl or Dolmars.

 

[Cut4fun]

Thanks Art. Great post. Maybe some will see what I was trying to get across in my post.
But I only did the extra 1/8-1/4 turn for gtg stuff.

 

[B_Turner]

There are two ways around it. The first is to find a non limited 7900 coil. The other, is to adapt a different ignition system to it. I have heard that they will easily turn a four stroking 15k stock if you can get around the limiter.

Are you saying that even stock the 7900 will be 4 stroking a little at 15k with a different coil?

I'm just trying to understand.

 

[charkan]

Just for giggles is there a bolt in non limited coil.

 

[Cut4fun]

Just for giggles is there a bolt in non limited coil.

Yes, but not in the U.S.

 

[Cut4fun]

From what I understand, the unlimited coil came in these RS7900's.

I gave up on the bolt in for mine and just sold the saw. It was a great woods ported 7900, just being held back by the coil IMO.

 

[Stihl Crazy]

Thanks Art. Great post. Maybe some will see what I was trying to get across in my post.
But I only did the extra 1/8-1/4 turn for gtg stuff.

When I race them I go 1/2-3/4 into the governor.

 

[Urbicide]

I am wondering how you identify an unlimited Dolmar ignition module from a limited one. With Husqvarna it is real simple. Are the unlimited ones still in production?

 

[nap69]

Anyone have a part no. for the non restricted coil?
Wondering if i can get them from germany

Regards
Neil

 

[tdi-rick]

Anyone have a part no. for the non restricted coil?
Wondering if i can get them from germany

Regards
Neil

there's only one coil pt # listed in the current parts list, (038 143 040, and it's described as the red coil)

All the other different US/ROW parts are listed.

 

[woodchuck361]

Will the 7900 pull a 36 inch bar? It says 32 is the max for it, but the 7300 also says that it will pull a 32? What gives if the smaller saw will pull the same size bar as the bigger it would stand to reason that the 7900 would pull a 36? any reason why it would not? Has anyone done it?

 

[B_Turner]

Will the 7900 pull a 36 inch bar? It says 32 is the max for it, but the 7300 also says that it will pull a 32? What gives if the smaller saw will pull the same size bar as the bigger it would stand to reason that the 7900 would pull a 36? any reason why it would not? Has anyone done it?

It'd be slow going but could be done on occasion with a sharp chain. I don't think the oiler was designed for that long of bar, though.

I'm with Ultra, run 24" and 28" only on my 7900s. But like him, I have bigger saws I grab for longer bars.

 

[04ultra]

I run 24" and 28" with full comp never anything longer...




.

 

[woodchuck361]

I run a 24 on my 361 and it runs GREAT but I have a job that the trees are all larger then 30 inch and I have been looking for an excuse to get a larger saw. I will not need a saw bigger then the 7900 and will honestly not use it that much. I just can't justify getting the larger saw and not be able to run a bar that will make one cut through the log. Yes the 32 would probably work for 70% of these larger trees but the 36 would do 99% of them. ?

 

[B_Turner]

It's common to have big bar lust, beyond what is really necessary. Somehow it just seems like a really long bar or two would make our life better somehow. I speak from experience here.

Something to think about when gettin long bars for those "occasional" big trees: Many will end up with a bigger saw eventually, so make sure you buy a mount that will work on your bigger saw.

For example, I have long bars for my 066 that I probably will never use again given I have a 3120 and 880. I'll keep them in case I end up with a 771 or whatever stihl calls the rumored 100+cc saw....

The nice thing about Dolmars and huskies is that all the large mount systems are the same. My 7900s, 371, 395, 3120 all take the same bar. For the 880 I had to buy it's own set of bars....Not so bad for my ES bars, but kind of painful with a 50" Cannon.

 

[04ultra]

The nice thing about Dolmars and huskies is that all the large mount systems are the same. My 7900s, 371, 395, 3120 all take the same bar. For the 880 I had to buy it's own set of bars....Not so bad for my ES bars, but kind of painful with a 50" Cannon.

Just goes to show you Big power saws need better heaver mounting.....:hmm3grin2orange: :hmm3grin2orange:



.

 

[motoroilmccall]

Well for a 36 your better off with a 066 or 394/395XP. The 7900 just is too small to run a 36" bar, even with full skip.

 

[B_Turner]

Just goes to show you Big power saws need better heaver mounting.....:hmm3grin2orange: :hmm3grin2orange:



.

I've wondered about that. Never had an issue running my 395 alot, but haven't run my 3120 enough to really know if the mount is a limitation. WIth your hotrod 3120s you may have a better idea on that.

Probably depends on cutting style, too. I run really sharp square skip 3/8 on all long bars through 50" so I think I am easier on the mounts than some.

But I do agree with the previous post that you should run at least a 660/395 with a 36. They both pull a 36 very well. I love my 7900s, but the difference in big wood is significant.

 

[04ultra]

I've wondered about that. Never had an issue running my 395 alot, but haven't run my 3120 enough to really know if the mount is a limitation. WIth your hotrod 3120s you may have a better idea on that.

Probably depends on cutting style, too. I run really sharp square skip 3/8 on all long bars through 50" so I think I am easier on the mounts than some.

But I do agree with the previous post that you should run at least a 660/395 with a 36. They both pull a 36 very well. I love my 7900s, but the difference in big wood is significant.

Is your 3120 running over 12K yet??




.

 

[woodchuck361]

So a 7900 with a muff mod making close to 6.5-6.7 h.p. is not enough to pull a 36 is it a torque issue? Stihl says the 650 which makes the same power will pull a 36. Whats the diff? Other than 5 cc.