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

[Stefaan]

Glad to hear they are running strong.

 

[Wilhelm]

Dolmar PS-6400, factory stock with AM piston, no MM is my favorite and gets ran the most!

 

[Steve]

Dolmar PS-6400, factory stock with AM piston, no MM is my favorite and gets ran the most!

Why so? Funny as this sounds I have never ran a stock 6400. From the second I get them I unwrap them and put a 7900 top end on it as do a muffler mod!

 

[Wilhelm]

Why so? Funny as this sounds I have never ran a stock 6400. From the second I get them I unwrap them and put a 7900 top end on it as do a muffler mod!

Up to 20" 3/8" B&C there is next to no advantage using a 7900 over a 6400 unless:
- You extremely drop the rakers on the 7900 chain , I sometimes go as low as .060"-ish for fun and stuff
- the operator is used to be hamfisted and forces the saw through each and every cut utilizing the saws bucking spikes
Yet the 7900 will consume significantly more fuel than the 6400 does utilizing same or identical chains.

Additionally, the logs I tend to buck are usually a mixed mess ranging from miserable 4" up to no more than 20" in diameter which makes the 7900 pure overkill.
I don't ever swap saws before i run the fuel tank dry or dull the chain just because the logs diameters vary!

I love my Dolmar PS-6400, she is the most universal all rounder in my possession - I don't ever wanna be without her.

I know everyone shuns the 6400 to be too heavy for a 60cc saw, I prefer her over my 6100 FOR WHAT I NEED AND USE MY SAWS FOR.
Just to be clear, there is nothing wrong with my 6100.
The 6400 just feels like she has more low end torque and that is something I prefer bucking hardwood logs.
High rpm saws kinda don't do it for the stuff I tend to buck unless it's a rare pile of fresh straight grain extremely clean beech logs!

It is a matter of personal preference and choice, no big deal.

Also, a truly sharp quality brand chain will easily make up for a 15cc PH difference, especially if the bigger cc PH is paired up with a sub par chain (no specific brands I think of to be named).
Again, a matter of personal preference and opinion, no big deal.

 

[PA Dan]

I said before the 6421 was damn impressive when I first ran it. Well built quality 60cc saw! Smoothest saw ever. Now that it's a 7910 I like it even better!

 

[Wilhelm]

 

[PA Dan]

 

[Steve]

Up to 20" 3/8" B&C there is next to no advantage using a 7900 over a 6400 unless:
- You extremely drop the rakers on the 7900 chain , I sometimes go as low as .060"-ish for fun and stuff
- the operator is used to be hamfisted and forces the saw through each and every cut utilizing the saws bucking spikes
Yet the 7900 will consume significantly more fuel than the 6400 does utilizing same or identical chains.

Additionally, the logs I tend to buck are usually a mixed mess ranging from miserable 4" up to no more than 20" in diameter which makes the 7900 pure overkill.
I don't ever swap saws before i run the fuel tank dry or dull the chain just because the logs diameters vary!

I love my Dolmar PS-6400, she is the most universal all rounder in my possession - I don't ever wanna be without her.

I know everyone shuns the 6400 to be too heavy for a 60cc saw, I prefer her over my 6100 FOR WHAT I NEED AND USE MY SAWS FOR.
Just to be clear, there is nothing wrong with my 6100.
The 6400 just feels like she has more low end torque and that is something I prefer bucking hardwood logs.
High rpm saws kinda don't do it for the stuff I tend to buck unless it's a rare pile of fresh straight grain extremely clean beech logs!

It is a matter of personal preference and choice, no big deal.

Also, a truly sharp quality brand chain will easily make up for a 15cc PH difference, especially if the bigger cc PH is paired up with a sub par chain (no specific brands I think of to be named).
Again, a matter of personal preference and opinion, no big deal.

No hate at all from me! I like that the 6400 works for your cutting. I too don't particularly care for my 6100 either when I have a dcs5030 that is much more my style. I keep a 28" bar on the 7901 and it only comes out on over 20" bucking/felling jobs. And you are correct. The 7900 does like fuel!


Oh, and where's my starter stickers?!

 

[huskyboy]

A 6400 is definitely a bit stronger in hardwood than a 6100. Not sure about softwood. I don’t cut that as much.

 

[Wilhelm]

Oh, and where's my starter stickers?!

I dunno what Yer talking about . . .

Big order is in the works.
Apologies for the extreme delay.

 

[Steve]

I dunno what Yer talking about . . .

Big order is in the works.
Apologies for the extreme delay.

Whenever, no rush on my end.

 

[Wilhelm]

In relation to complains regarding easily flooded Dolmar/Makita 64xx/73xx/79xx units during cold starts, here is my finding.

As You can see by my signature, I have four of these, all factory stock, all in working condition.
My PS-6400 has an AM piston kit no MM, my PS-7300/7310/7900 are factory original and have a mild MM.
My PS-6400 & PS-7900 do not feature a DeCo valve, my PS-7300 & PS-7310 do.
All four have a different year of manufacturing.
All four have different, even unknown runtime on them.
They all behave the same!


If You have cold start flooding issues with these saws try this starting procedure:
- do not wear hearing protection as the cold start pop tends to be subtle
- do not utilize the DeCo valve if Your unit features one
- give the saw a pull without engaging choke+high idle , if she pops or even springs to life You just prevented flooding Your saw!
- engage choke+high idle , give the saw 2 to 4 pulls the most depending whether she pops or not , obviously You don't keep pulling once she pops
- disengage choke keeping high idle , give the saw 2 to 3 pulls , she should spring to life

I have uploaded videos to my YT channel portraying the above stated procedure on all four saws.
The saws behavior is repeatable.

The other day my PS-6400 sprung to life during a "cold start", one pull no choke no high idle - she came to life and just idled away.
Had I choked her she'd have flooded.
It was an afternoon of a very hot day!

Cheers

 

[M2theB]

New to this thread and haven’t been through the previous pages, except the first one.

Picked this one up today for a more than a reasonable price. Seems to have a lube leak at the split.

I’ll need to pile back through the thread to catch up.
6401 with 6421 side armor

 

[huskihl]

New to this thread and haven’t been through the previous pages, except the first one.

Picked this one up today for a more than a reasonable price. Seems to have a lube leak at the split.

I’ll need to pile back through the thread to catch up.
6401 with 6421 side armor

If you end up splitting it, I’d loctite the bearings to the crank and case

 

[SOS Ridgerider]

New to this thread and haven’t been through the previous pages, except the first one.

Picked this one up today for a more than a reasonable price. Seems to have a lube leak at the split.

I’ll need to pile back through the thread to catch up.
6401 with 6421 side armor

I’d venture to say that price was extremely reasonable. Lol

 

[Allanb8d]

In relation to complains regarding easily flooded Dolmar/Makita 64xx/73xx/79xx units during cold starts, here is my finding.

As You can see by my signature, I have four of these, all factory stock, all in working condition.
My PS-6400 has an AM piston kit no MM, my PS-7300/7310/7900 are factory original and have a mild MM.
My PS-6400 & PS-7900 do not feature a DeCo valve, my PS-7300 & PS-7310 do.
All four have a different year of manufacturing.
All four have different, even unknown runtime on them.
They all behave the same!


If You have cold start flooding issues with these saws try this starting procedure:
- do not wear hearing protection as the cold start pop tends to be subtle
- do not utilize the DeCo valve if Your unit features one
- give the saw a pull without engaging choke+high idle , if she pops or even springs to life You just prevented flooding Your saw!
- engage choke+high idle , give the saw 2 to 4 pulls the most depending whether she pops or not , obviously You don't keep pulling once she pops
- disengage choke keeping high idle , give the saw 2 to 3 pulls , she should spring to life

I have uploaded videos to my YT channel portraying the above stated procedure on all four saws.
The saws behavior is repeatable.

The other day my PS-6400 sprung to life during a "cold start", one pull no choke no high idle - she came to life and just idled away.
Had I choked her she'd have flooded.
It was an afternoon of a very hot day!

Cheers

Thanks for the write up. I've experienced this issue before, usually if it's been sitting for a couple weeks in hot weather (I use premixed so no gas issue). If the saw has been ran the day before, it will start right up.

I think I read somewhere that flipping the shutter helps? Winter mode in summer, or something like that.

 

[Stefaan]

If you end up splitting it, I’d loctite the bearings to the crank and case

Is there a problem with either the bearings or case? What loctite would one use for this application?

 

[Wilhelm]

I think I read somewhere that flipping the shutter helps? Winter mode in summer, or something like that.

I don't think letting the engine ingest hot cylinder air in the summer is a good idea.

If flipping the shutter to winter mode truly helps with cold starts in the summer, then only because the engine may be able to suck in air a little easier with the winter shutter open.
Still, I wouldn't want my saws to run on cylinder heated air in the summer for prolonged periods.

 

[huskyboy]

Popoff pressure in @Wilhelm saws is probably a tad low. The tank vent design on these saws also causes a lot of pressure to build up in the tank in the summertime. Which can force the needle open flooding the saw.

 

[huskihl]

Is there a problem with either the bearings or case? What loctite would one use for this application?

The bearings don’t fit as tight as others. Both on the crank and case. I’ve used both loctite bearing retainer and red. Figured it would require heat to remove the bearings next time anyway, so…