What do you know about redheads?

[Stihlmar]

Redheads. They sure are pretty aren’t they? A few years older but they just Do something for a guy.

By redhead, I am speaking of the Dolmar variety.

I have a lead on a like new 7300 red top. I know there are hundreds of threads about the P/C swap. But my interests are in the top covers. Will a red top fit on a 7910 cylinder. I thought i read somewhere that there was a air duct difference. If anybody had one or pictures of either that would be awesome.

I’m Thinking a ported 7910 red top with a full wrap and new 28” Dolmar bar.

 

[Wilhelm]

I think my PS-7300 feels as strong as my PS-7900 - both are stock featuring identical modest muffler mods.

Having all three cc power heads I'd never convert my 73 to a 79 - there is something about her that I can't quite put my finger on.
This is mine, she has a new spark plug now, the champion plug she was running in that video was in three parts - still worked though

My yesterday's play dates, mostly redhead's.
That's my PS-7300 wearing the 36" Iggesund Forest bar.

She pulled that setup nicely, have to up videos to the Tube.

A previous joyful day


Photo shoot, the PS-7300 wasn't yet mine then.


If porting, then of course go all out.

To answer Your question, the only cylinder difference throughout the two decades of production of these saws is the placement of the decompression valve.
The mufflers also changed from empty can to SLR.

 

[Wilhelm]

P.S.:
Sorry, I don't strip down my redheads, take pictures and then post them on the internet!

Well, actually I do!
But I don't have any nude pictures of my redheads at my disposal right now.

 

[Chainsaw Jim]

It's hard not to picture jugs with freckles.

 

[Lightning Performance]

It's hard not to picture jugs with freckles.

And a feisty tude

 

[Stihlmar]

Thank you @Wilhelm ! Have been jealous of your lineup for awhile now.

Interesting to hear about power output compared to the 79. My smurf has always impressed me. Bought it right and can’t justify for what it does to upgrade.

Don’t have a real reason to do a swap if I get it bought. Just cuz I guess. Would be a saw that only gets used 1 or 2 times a year.

Shelf queen. Conversation piece. Don’t know anybody with one of those.....

 

[Wilhelm]

If the price is right I'd get that Dolmar PS-7300!

The power comparison between my PS-7300 & PS-7900 is nothing scientifically proven, it's just a gut feeling.

For what it's worth, my PS-7300 does seem to be a bit lean, I have to get rid of the carbs limiters and retune.

 

[Wilhelm]

P.S.:
I ran my Dolmar PS-6400 with my 36" B&C setup last Friday!
Granted the log wasn't 36" diameter anymore, but she pulled the chain nicely.
It was more for giggles than to prove anything.

There is nothing wrong the 64cc PH of this saw model lineup, they are great engines just extremely underappreciated and underrated - some bull crap regarding power to weight that I never understood.

 

[cgraham1]

The decomp hole is on the clutch side of the 7910 jug, and the opposite side of the 7900/7300 jug.... meaning the hole in the nice red top cover won’t line up with the decomp on the 7910 jug. Probably why the top end kits come with a new black top cover to match. Id just plug the decomp and keep the red top, or find an actual 7900 cylinder to swap on there.

 

[cgraham1]

P.S.:
I ran my Dolmar PS-6400 with my 36" B&C setup last Friday!
Granted the log wasn't 36" diameter anymore, but she pulled the chain nicely.
It was more for giggles than to prove anything.

There is nothing wrong the 64cc PH of this saw model lineup, they are great engines just extremely underappreciated and underrated - some bull crap regarding power to weight that I never understood.

How are you even oiling a 36” bar? My 7900’s oiler was maxed out with a 28”.

 

[Adirondackstihl]

7900 with 7910 top end

 

[Lightning Performance]

6100's are pretty fast right out of the box.
Guys say, idk, they get better economy running the SLR mufflers.
I like smurfs, same saw, in 64xx, 7xxx. ... The red heads seem to be just the same, all good. Good AV big tanks but a bit long when built in 60cc platforms with a 20 bar. In 70-80cc it feels petty good. They balance well with a 24-30 bar. Parts interchange across platforms of blue and red is nice. All run the same bottom end and guts. What's not to like.
Mine are being set up for beam and mill duty now. They have the right stuff to handle medium duty work IMO. 6400 20" 058RM. 6400 BB54mm 28 Total square 3/8 050RS or skip.

 

[Marshy]

So, theres not many threads on OPE for a guy to learn about Dol's. I just picked up a 7900, whats the difference between the 7900 cylinder and the 7910?

So far I read the decomp hole is on the clutch side of the 7910 (opposite of 7900) and the 7910 has SLR muffler.

Can I put a 7900 muffler on a 7910?

Is the intake boot from the 7900 plug and play?

Is there a performance difference between the two?

 

[Adirondackstihl]

Can I put a 7900 muffler on a 7910?.......YES

Is the intake boot from the 7900 plug and play?.....YES

Is there a performance difference between the two?.......YES

 

[Wilhelm]

How are you even oiling a 36” bar? My 7900’s oiler was maxed out with a 28”.

View attachment 119859

I love that picture of Yours!

I have no idea why You guys have issues with oiling long bars using the PS/DCS/EA-64xx/73xx/79xx power heads!
Since last Saturday I now ran my 36" B&C setup on all my large frame girls.
I bucked a large diameter oak log and there was plenty of oil on the chain as I swapped the B&C between power heads.
It simply works for me on all four of my big girls, they're soaking wet asking for more.

7900 with 7910 top endView attachment 119861View attachment 119862

Lovely!
You have good taste Sir.

So, theres not many threads on OPE for a guy to learn about Dol's. I just picked up a 7900, whats the difference between the 7900 cylinder and the 7910?

So far I read the decomp hole is on the clutch side of the 7910 (opposite of 7900) and the 7910 has SLR muffler.

Can I put a 7900 muffler on a 7910?

Is the intake boot from the 7900 plug and play?

Is there a performance difference between the two?

Congratulations on Your new to You saw!

You can mount the non-SLR muffler on a PS-7910 cylinder, but not the SLR muffler on a PS-7900 cylinder unless You remove the "tube" first.

Carb & carb boot should be direct swap from PS-7900 to PS-7910.

The PS-7910 has a lower HP rating than the PS-7900, 5.7HP vs 6.2HP - this relates to fully stock factory made units.
The PS-7910 comes with a lower limited coil than the PS-7900, 12.800rpm vs 13.500rpm - again, this relates to factory stock units.
My best guess is that the power loss is due to the SLR muffler.

Why would You want to swap over to a PS-7910 cylinder?
Is Your PS-7900 cylinder damaged?
If not damaged, or if salvageable I'd keep the PS-7900 cylinder and replace piston & ring if needed.

I can not comment which one of the two cylinders if more favorable , but I bet the porters can shed some light on that matter.

 

[Wilhelm]

So, theres not many threads on OPE for a guy to learn about Dol's. I just picked up a 7900, whats the difference between the 7900 cylinder and the 7910?

So far I read the decomp hole is on the clutch side of the 7910 (opposite of 7900) and the 7910 has SLR muffler.

Can I put a 7900 muffler on a 7910?

Is the intake boot from the 7900 plug and play?

Is there a performance difference between the two?

IPL's:
http://opeforum.com/threads/dolmar-ipls-official-dolmar-germany.9320/

User manuals, mostly in German but nice for looking up specs:
http://opeforum.com/threads/dolmar-owner-manuals-official-dolmar-germany.12091/

 

[Adirondackstihl]

I love that picture of Yours!

I have no idea why You guys have issues with oiling long bars using the PS/DCS/EA-64xx/73xx/79xx power heads!
Since last Saturday I now ran my 36" B&C setup on all my large frame girls.
I bucked a large diameter oak log and there was plenty of oil on the chain as I swapped the B&C between power heads.
It simply works for me on all four of my big girls, they're soaking wet asking for more.


Lovely!
You have good taste Sir.


Congratulations on Your new to You saw!

You can mount the non-SLR muffler on a PS-7910 cylinder, but not the SLR muffler on a PS-7900 cylinder unless You remove the "tube" first.

Carb & carb boot should be direct swap from PS-7900 to PS-7910.

The PS-7910 has a lower HP rating than the PS-7900, 5.7HP vs 6.2HP - this relates to fully stock factory made units.
The PS-7910 comes with a lower limited coil than the PS-7900, 12.800rpm vs 13.500rpm - again, this relates to factory stock units.
My best guess is that the power loss is due to the SLR muffler.

Why would You want to swap over to a PS-7910 cylinder?
Is Your PS-7900 cylinder damaged?
If not damaged, or if salvageable I'd keep the PS-7900 cylinder and replace piston & ring if needed.

I can not comment which one of the two cylinders if more favorable , but I bet the porters can shed some light on that matter.

Don’t know the details, but I’m 95% sure builders prefer the 7910 cylinder.
7910 = slab sided piston
7900 = windowed piston

 

[Wilhelm]

Don’t know the details, but I’m 95% sure builders prefer the 7910 cylinder.
7910 = slab sided piston
7900 = windowed piston

Potatoes tomatoes - or something like that!
I'm guessing it's a porting thing - mine are all stock.

I like my PS-7900, she's got more grunt than I can utilize!
I run a 72DL loop with rakers down ~1mm on her just to actually make it worth while picking her off the shelve.
A stock PS-7900 is a beast, and sexy to boot.


My PS-6400 is my main go to saw, but it is getting harder to decide which one to pick so I tend to show them all a little bit of attention.

 

[Adirondackstihl]

They are one of the nicest looking saws for sure!

 

[cgraham1]

Why would You want to swap over to a PS-7910 cylinder?
Is Your PS-7900 cylinder damaged?
If not damaged, or if salvageable I'd keep the PS-7900 cylinder and replace piston & ring if needed.

The saw in question is a 7300... hence the desire to swap the larger cc top end onto the saw. I personally wouldn’t do the swap unless the cylinder was damaged, or I happened to have a spare 7900 top end already.