Dolmar 64xx/73xx/79xx series, smurfs and solo 665/675/681 thread

[RI Chevy]

Lol
7900 has a few mods. Is the 064 stock? Or Masonized as well?
True though. Not much difference with saws in smaller rounds.

 

[huskyboy]

Lol
7900 has a few mods. Is the 064 stock? Or Masonized as well?
True though. Not much difference with saws in smaller rounds.

The 7900 has the ports widened and blended along with other stuff. The 064 just has a gasket delete and muffler mod/timing advanced, not taken as far as the 7900. The porting is known to be good in the 064 to begin with compared to the 660. Strong saw to begin with, imo doesn’t need much to wake up. Same for 7900. I would choose the 7900 over the 064 for just about everything other than maybe a long bar. It’s just a more modern, nicer saw to use all day. That said, the 064 is a collectible and rare. They were a incredible saw in there time and ahead of there time imo.

 

[Wilhelm]

Dolmar PS-7900 & 36" B&C in beech

 

[huskyboy]

Dolmar PS-7900 & 36" B&C in beech
View attachment 196485 View attachment 196486 View attachment 196487 View attachment 196488

They will get’r done surprisingly well with big bars if you don’t abuse them and really I found the oiler isn’t that bad as some say unless the plastic nub is worn out (easy fix). Or the saw is modified/ported with a need for more oil.

 

[Wilhelm]

They will get’r done surprisingly well with big bars if you don’t abuse them and really I found the oiler isn’t that bad as some say unless the plastic nub is worn out (easy fix). Or the saw is modified/ported with a need for more oil.

That's what I keep saying, on both accounts power and oiling.

 

[huskyboy]

Well the 7301 has done well logging so far. Buckin a good size ash. Verdict so far is that it’s a absolute miser on fuel. Has good torque, runs kinda like a 372xp with more grunt. The ergonomics and responsive rev up of the motor are also nice when limbing or topping. The smooth power delivery and smooth av make for a comfortable saw to run all day.

 

[CLEARCUT]

I compared the 7900 and 572 again today down in the strip. Although it is not fair, as the 572 is ported, and the 7900 is just muffler modded, they seem fairly equal in power. I’d be really curious to run a 7900 ported, but I like it just muffler modded. It seems to be really easy to tune compared to my 461’s. Just seems like it doesn’t need adjustment as often. Sometimes I kinda like having control of the carb instead of autotune.
Definitely a keeper and it is still holding up here no problem. I have ran a 36 and 42 on it even, and it has impressive torque for an almost stock saw. I would definitely choose it over my 461’s, and they are a great saw. Just thought I would give you guys an update.

 

[mettee]

You port that thing you will be in love

 

[huskyboy]

I compared the 7900 and 572 again today down in the strip. Although it is not fair, as the 572 is ported, and the 7900 is just muffler modded, they seem fairly equal in power. I’d be really curious to run a 7900 ported, but I like it just muffler modded. It seems to be really easy to tune compared to my 461’s. Just seems like it doesn’t need adjustment as often. Sometimes I kinda like having control of the carb instead of autotune.
Definitely a keeper and it is still holding up here no problem. I have ran a 36 and 42 on it even, and it has impressive torque for an almost stock saw. I would definitely choose it over my 461’s, and they are a great saw. Just thought I would give you guys an update.

How’s the fuel economy compare? The 572 is definitely better on gas stock, it’s like a prius lol. But a full ported 572 vs a muffler mod 7900 “wood” be interesting.

 

[CLEARCUT]

How’s the fuel economy compare? The 572 is definitely better on gas stock, it’s like a prius lol. But a full ported 572 vs a muffler mod 7900 “wood” be interesting.

I would say that the 7900 is better on fuel by a little bit. The 572 definitely is using more fuel than when it was stock. It doesn’t run very lean.

 

[CLEARCUT]

You port that thing you will be in love

I might try to do a bit more to it eventually. I’d like to port myself, but haven’t broke into that yet. I’m not scared to grind on the muffler though!

 

[166]

 

[Wilhelm]

OEM PS-7910 52mm pistons, part number 038.132.070

 

[David _4]

Those sure are pretty!

 

[mortalitool]

I am building myself a Dolmar from some parts saws I purchased. I can either go 73 or 79. I have both jugs. But only have a piston for the 7300.
The 7900 jug is missing the piston.

I know some guys have tried using an 046 piston. Are guys using any other piston option in the 79 ?? 038 mag 2? 064 ?

I know i can use a 7910 piston. But exploring options. I have a lathe and can machine is if need be.

Leaning towards just using the 73 top end

I have never been into one of these and am really excited to start building one for myself.

 

[Deets066]

I am building myself a Dolmar from some parts saws I purchased. I can either go 73 or 79. I have both jugs. But only have a piston for the 7300.
The 7900 jug is missing the piston.

I know some guys have tried using an 046 piston. Are guys using any other piston option in the 79 ?? 038 mag 2? 064 ?

I know i can use a 7910 piston. But exploring options. I have a lathe and can machine is if need be.

Leaning towards just using the 73 top end

I have never been into one of these and am really excited to start building one for myself.

The 046 piston works pretty good, 272 can be used as well. If it’s just for work, I’d stick with the slab sided 7910 piston

 

[mortalitool]

The 046 piston works pretty good, 272 can be used as well. If it’s just for work, I’d stick with the slab sided 7910 piston

Right on! Thanks Deeter.

It will ultimately be used for a work saw. play a few times a year.

Where is the best place to get a slab side 7910 peeston?

 

[Deets066]

Right on! Thanks Deeter.

It will ultimately be used for a work saw. play a few times a year.

Where is the best place to get a slab side 7910 peeston?

I got my last top end from Carl. @Miller Mod Saws

 

[huskyboy]

The lightweight slab side piston vibes a tad less than the the 046 piston. Nothing to complain about really, just something I noticed running back to back. This is because the 046 piston is significantly heavier than the dolmar piston. That said the 046 piston can run good in them.

 

[huskihl]

The lightweight slab side piston vibes a tad less than the the 046 piston. Nothing to complain about really, just something I noticed running back to back. This is because the 046 piston is significantly heavier than the dolmar piston. That said the 046 piston can run good in them.

Prolly not so many vibes with .040" spun off the top of the piston