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

[Fruecrue]

Ok I've got a couple questions here if anyone would care to jump in. I'm looking at going through my 7900 and freshening it up. The saw is stock other than a gutted muffler with the outlet opened up as far as the deflector Will allow. Im also planning on sending the carb to Rich for his mods.

1. I heard that the slab side piston is quite a bit lighter than the windowed piston. What is the actual weight difference of between the piston/pin/ring/clip assemblies?

2. Where's the best source for said slab side piston?

3. Has anyone tried the windowed piston from HL and does it use the stock width ring? Thinking about running one them with a caber ring if so since they're only $25.

4. Will "clipping" the bottom corners of the cylinders(to match the piston) at the lower transfers and lightly blending the lowers as talked about previously make a noticeable difference? (On a mostly stock saw)

Thanks
Jeff

1) I think the total weight difference was 7-9 grams, I’d have to check my notes.
2) I haven’t seen OEM 7910 piston for sale anywhere by itself.
3)I bought a Hyway brand piston from them, showed up Golf brand (which I’m not s fan of, seen too many defects). No response when I sent them an inquiry.
4)don’t know. Some like the tight case, some like smoother flowing passages. Would be a neat test to do it last and time some cuts before and after.

 

[Fruecrue]

This it...?

Yes!
Sooooo sexy.
Some even have a flashlight mounted on them.

 

[PA Dan]

They are really cool!

https://supervac.com/saws/sv3-20/

 

[huskyboy]

You can get the slab side from Nate I believe.

 

[mdavlee]

You can get the slab side from Nate I believe.

You could but the price was over $100 if I remember correctly. I’d buy a wiseco from Digger Dave for that price.

 

[Fruecrue]

They are really cool!

https://supervac.com/saws/sv3-20/

I got the bar and chain too.

 

[usmcbuckwild]

I just want that aluminum pull handle!

 

[mettee]

Yeah he sure has , he likes it alot

Are you THE "aj" he refers to?

 

[Fruecrue]

I just want that aluminum pull handle!

Agreed, mine doesn’t have that.
Reminds me of brass knuckles.

 

[ajschainsaws]

Are you THE "aj" he refers to?

Yes sir

 

[mettee]

Very cool. Next time send me the super sweet saws

 

[usmcbuckwild]

Have to finish up the 123 Super to 143 conversion, start on the 117, i have to find the 5105 that is somewhere in the garage and still waiting on parts for the 9010.

 

[Fruecrue]

Finished porting the fire saw. Just need to find some time to throw it together.

 

[mettee]

Man that intake, she wide...

 

[mettee]

Ok I've got a couple questions here if anyone would care to jump in. I'm looking at going through my 7900 and freshening it up. The saw is stock other than a gutted muffler with the outlet opened up as far as the deflector Will allow. Im also planning on sending the carb to Rich for his mods.

1. I heard that the slab side piston is quite a bit lighter than the windowed piston. What is the actual weight difference of between the piston/pin/ring/clip assemblies?

2. Where's the best source for said slab side piston?

3. Has anyone tried the windowed piston from HL and does it use the stock width ring? Thinking about running one them with a caber ring if so since they're only $25.

4. Will "clipping" the bottom corners of the cylinders(to match the piston) at the lower transfers and lightly blending the lowers as talked about previously make a noticeable difference? (On a mostly stock saw)

Thanks
Jeff

If you get into the cylinder you might as well do it all. Doing just the corners on the lower will not yield what they could by doing the intake, exhaust and upper transfers as well.

 

[mettee]

Have to finish up the 123 Super to 143 conversion, start on the 117, i have to find the 5105 that is somewhere in the garage and still waiting on parts for the 9010.

Did that old man give you that 9010?

 

[jk14]

Looks like the 7900 I picked up last week turned out to be a dud. Had some issues with the chain(that was already on it) and when I went to inspect the issue I noticed the crank had some play.

Figured I'd tear it down and see what was going on, hoping for a wiped out crank bearing. Nope, PTO bearing pocket is wallowed out. Surprisingly the top end looks perfect. Not sure what to do with it now, find a new case half or part it out, hmmm. Decisions.

 

[dahmer]

@Mac&Homelite See above post, it ain’t just you.

 

[mettee]

There used to be some cases on ebay for decent prices. Not sure how that stacks up against new case halfs.

How does the crank look over all? Is there a lot of wear on the clutch bearing surface or anything like that?

Dahmer you have seen this in other saws?

I tried to pull a bearing out of my homedepot makita and that sucker was in there. Heating and pressing it wouldn't budge with the amount of force I was willing to use.

 

[dahmer]

There used to be some cases on ebay for decent prices. Not sure how that stacks up against new case halfs.

How does the crank look over all? Is there a lot of wear on the clutch bearing surface or anything like that?

Dahmer you have seen this in other saws?

I tried to pull a bearing out of my homedepot makita and that sucker was in there. Heating and pressing it wouldn't budge with the amount of force I was willing to use.

@Mac&Homelite is fighting a 6401 that he was converting to 7900. Clutch side crank bearing fit is wore oversize and it also messed up his crank. He can give you more details than I.