DOLMAR/MAKITA The Official Sachs Dolmar Dolmar Makita Dolmar Chainsaws Thread

[Shane¹]

@old_sir_henry that came out really nice 120 is a solid runner. @mgr1 143 cylinders are pretty rare got a saw to put it on?

 

[old_sir_henry]

The 120 runs fine and starts well. She feels heavy compared to a 120 si this is due to the fact
that many parts are made of metal rather than plastic: Starter housing, recoil drum, cylinder hood and tank unit.
With this 120 the air-filter cover already is plastic, my previous one had a metal cover.
The 120si is significantly more powerful and agile than the 120, much more than you would expect from 7 cc of additional displacement.

 

[Shane¹]

I would agree I feel a lot of the extra comes from the ignition on the 120si. A 120 super is not the same as an si even with the extra 7cc. I still like running a 120 though

 

[old_sir_henry]

Thats probably true. I haven't compared a 120 super againt a 120si but I think
the 120si will outperform the super

 

[mgr1]

@old_sir_henry die er heel mooi uitkwam. 120 is een solide hardloper. @mgr1 143 cilinders zijn behoorlijk zeldzaam. Heb je een zaag om hem op te zetten?

De 143 decocilinders zijn gemakkelijk te vinden. Dit is een non-deco cilinder.

I have a few oldies...

 

[Ketchup]

Hi guys,
I’m making plans to rebuild a 7910 and had a couple questions.
Other than the side the decomp is on, is there any difference in the cylinder porting between 7900 and 7910? Do you guys feel one is stronger than the other? I know the 7900 has the higher limit coil, but does the actual cylinder make any difference?
Second, the 7900 and 7910 have a slab sided piston with a lot of clearance around the transfer lowers but a Solo 681 has a windowed piston with less clearance for the lowers. Is there any advantage to using a 681 piston? Perhaps one is lighter than the other?
Third, since 681’s have a longer stroke, I’m thinking about swapping a 681 crank into my 7910. Does anyone have any advice in that department?

I appreciate your time fellas.

 

[SOS Ridgerider]

Hi guys,
I’m making plans to rebuild a 7910 and had a couple questions.
Other than the side the decomp is on, is there any difference in the cylinder porting between 7900 and 7910? Do you guys feel one is stronger than the other? I know the 7900 has the higher limit coil, but does the actual cylinder make any difference?
Second, the 7900 and 7910 have a slab sided piston with a lot of clearance around the transfer lowers but a Solo 681 has a windowed piston with less clearance for the lowers. Is there any advantage to using a 681 piston? Perhaps one is lighter than the other?
Third, since 681’s have a longer stroke, I’m thinking about swapping a 681 crank into my 7910. Does anyone have any advice in that department?

I appreciate your time fellas.

To my knowledge the cylinder porting is similar on the old PS-7900 and the PS-7910/EA7900, although some things changed, like the decomp location. The piston did change from windowed to solid. The current oem PS-7910/EA7900 cylinders all have the slab sided piston. The older PS-7900 had the windowed piston, but the newer offering of the older PS-7900 oem p/c comes with the slab sided piston. That kit goes by the description "DCS7901", which was a saw that was never officially offered over here, but the p/c kit is. There are places that still have them in stock.

I don't know if there would be a benefit to using the windowed 681 piston in that set up, but I do believe the pin to crown height is a tad bit taller on the 681 piston than on the 7900 piston.

The crank swap has been done before. Ole' @Fruecrue did it a few years ago, and that saw ran great!

Stroking a Dolmar 7900

Grab your popcorn boys and girls. Hold on to your underwear, we’re headed for destruction!

opeforum.com

I'm a little rusty on the above info, but @huskihl may be able to shed some more light on it for you. Especially from a performance standpoint.

 

[huskihl]

To my knowledge the cylinder porting is similar on the old PS-7900 and the PS-7910/EA7900, although some things changed, like the decomp location. The piston did change from windowed to solid. The current oem PS-7910/EA7900 cylinders all have the slab sided piston. The older PS-7900 had the windowed piston, but the newer offering of the older PS-7900 oem p/c comes with the slab sided piston. That kit goes by the description "DCS7901", which was a saw that was never officially offered over here, but the p/c kit is. There are places that still have them in stock.

I don't know if there would be a benefit to using the windowed 681 piston in that set up, but I do believe the pin to crown height is a tad bit taller on the 681 piston than on the 7900 piston.

The crank swap has been done before. Ole' @Fruecrue did it a few years ago, and that saw ran great!

Stroking a Dolmar 7900

Grab your popcorn boys and girls. Hold on to your underwear, we’re headed for destruction!

opeforum.com

I'm a little rusty on the above info, but @huskihl may be able to shed some more light on it for you. Especially from a performance standpoint.

I couldn’t tell much difference between piston performance but always thought the slr type newer cylinders ran a hair better

 

[Wilhelm]

I couldn’t tell much difference between piston performance but always thought the slr type newer cylinders ran a hair better

The exhaust outlet is bigger, will breathe easier once the SLR is removed.
I love my MM'ed PS-7310!

 

[Wilhelm]

My secondary PS-7900 with 24" B&C at it, cherry

 

[Powerstroke Cowboy]

I've got a slab side piston and a 681 crank on the shelf to put in a 7901 over the winter. There will be "other" supporting mods to go with it.

If you beat me to it @Ketchup feel free to post how it went. A build thread would be great!

 

[old_sir_henry]

I did a similar job about 4 years ago. Had to grind the crankcase in order to fit the larger Solo crank.
Pictures https://opeforum.com/threads/the-of...akita-dolmar-chainsaws-thread.694/post-976611

 

[Wilhelm]

Dolmar PS-6100 CE

 

[Powerstroke Cowboy]

Dolmar PS-6100 CE

View attachment 399981 View attachment 399982

Is that real Carbon Fiber? Or is it a coating?

 

[Wilhelm]

It is just paint, but OEM.
The spike is OEM too.

 

[Powerstroke Cowboy]

It still looks neat. How rare is the CE model?

 

[Wilhelm]

It still looks neat. How rare is the CE model?

@old_sir_henry might know, he is the German Dolmar know-it-all!

I stumbled upon mine, though it was a custom paint job and spike just to find out she is OEM special after having purchased her.
Not that she features special performance, it is just cosmetic - still, with the Dolmar brand suspended she IS special!

 

[old_sir_henry]

@old_sir_henry might know, he is the German Dolmar know-it-all!

Don't overestimate me, please! The carbon edition was offered IIRC around late 2013 and 2014 when selling rates of the 6100 seemed not to meet the company's expectations. Can't tell you how many factury supplied 6100-CE shipped but once in a while you'll find one and saws with customer-applied carbon-foil-look as well.
If any of the 6100 will make as a collector's item, it probably will be the CE

 

[Wilhelm]

Don't overestimate me, please! The carbon edition was offered IIRC around late 2013 and 2014 when selling rates of the 6100 seemed not to meet the company's expectations. Can't tell you how many factory supplied 6100-CE shipped but once in a while you'll find one and saws with customer-applied carbon-foil-look as well.
If any of the 6100 will make as a collector's item, it probably will be the CE

Old_Reliable_Sir_Henry, one can count on You to be more informative than any Dolmar (Makita) official!

Thank Tou very much!

 

[old_sir_henry]

A few weeks back this one arrived as shown: A PS-5000 soaked in oil

Was sold as defectve non-runner, had a seized piston and the usual scratches. marks and dents. A little TLC, a new piston, carb diaphragms and such brought her back to live: