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

[mettee]

Makes sense. The Solo is an overbuilt Dolmar. Longer crank and bigger bearings prolly make up more weight than extra screws, fuel lines and foam. But then again, I'm a chef so what do I know.

Do you make a good steak?

 

[Sportfury70]

 

[Sportfury70]

Old pics, but just re-read the whole thread. Mild port, timing adv, MM. Fun saw, love these things!

 

[huskyboy]

The 7300 isn’t QUITE as strong as a good 7900. But it’s so close that most wouldn’t be able to tell a difference unless someone told them it was a 7300. All were fairly close in the test. The only real difference I could feel was the 046 piston saw vibrates more than the stock piston saws. Makes sense because the 046 piston is heavier than the stock piston.

 

[TreeLife]

They sound so good.

 

[Wilhelm]

The 7300/7310's are sleeper 79'ers.

As long as the chain is sharp my PS-7310 holds higher in cut rpm's than my PS-7900 wearing my 36" B&C setup.
Once the chain gets dull the PS-7900 has more grunt to keep pulling the chain without giving a feeling of being raped.

My PS-7900 sports bigger dawgs than my PS-7310, she still feels stronger at lower rpm's.

 

[RI Chevy]

Different coil on 7300? Than 7910?

 

[huskyboy]

Different coil on 7300? Than 7910?

6400/7300/7900 = 13,500 rpm coil. 7310/7910 = 12,800 rpm coil. Coil can be swapped/interchanged across the different models. The coil limit doesn’t affect rpm in the cut, although the 12,800 coil does make it more of a pain the azz to tune. Especially on a ported saw. I prefer the 13,500 coil.

 

[RI Chevy]

Ahhh. Very good. Thank you...

 

[huskihl]

Just to add some confusion, now the new Makitas that are red are called a xx00, but are the same as the xx10 or xx21 when they were blue. ‘Tis great.....

 

[RI Chevy]

Wow

 

[Wilhelm]

Just to add some confusion, now the new Makitas that are red are called a xx00, but are the same as the xx10 or xx21 when they were blue. ‘Tis great.....

Buy Dolmar's, no confusion!

 

[WKEND LUMBERJAK]

Buy Dolmar's, no confusion!

If you like that series its really not.

 

[Sportfury70]

I run mine pretty fat, but it has the 13,5 coil. Just got a tach, it was running 13,3 ish by ear tuning, pretty proud of myself LOL. I’ll wait to adjust until I can tune it by the tach in some wood. That timing advance I feel made it easier to tune. Wasn’t much of an adjustment but seems like it’s a must if you port your saw.

Resisting the urge to pull the jug and cut the base. Don’t think it needs it at all, but the thought of squeezing a few more ponies out of it is a hard thing to resist.

 

[huskyboy]

Interesting. They both gained but the bigger saw benefits a little more from the increased airflow. Makes sense. They both had thinned shafts and drilled jet before... and after is when I bored out the venturi and got the results above.

 

[ferris]

16% is a lot.
How much wider do u make the venturi?

 

[huskyboy]

16% is a lot.
How much wider do u make the venturi?

It’s 16.6mm stock, which is rather small for a almost 80cc saw. I take it to about 17-17.5mm. For reference a 385xp is 17.5mm and a 064 is 19mm. It’s easiest to just bolt on a HD12 to the 7900 (17.5mm) but those are almost NLA and rather pricey. The zama works good after mods.

 

[mettee]

Any pics?

 

[huskyboy]

Any pics?

I use a carbide burr with the choke shaft removed out of my way and carefully open up the venturi with a shop vac hooked to the other end to catch the filings. You can go crazy with thinning the shafts/screws, but I found if you go to far they weaken and can break. I am looking for a reliable worksaw. You will have to drill this hole after to be able to supply enough fuel. When you increase the size of the venturi, it pulls less fuel from the nozzle and you have to compensate by drilling the carb. I found .55 - .60 to work depending on your elevation. You might not have to drill it if your above say maybe 3,000ft elevation if I had to guess. All of the above is stuff that I would recommend trying on a junk carburetor before you do the one on your saw. It’s very easy to destroy the carburetor.

 

[mettee]

Seems like a simple ebough mod. I like it.

A little poleman mod on the jet too.

Reminds me I need a couple junk zamas...