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

[huskyboy]

Same bar and chain, maple logs and better tune!

Now that’s what I’m talking about. Nice!

 

[mettee]

It's got a bad tank vent....

 

[huskyboy]

It's got a bad tank vent....

How could you tell that from the video?

 

[huskyboy]

If anything I found the tank vents on these saws to be better than what stihl or husky have on there saws. The only ones that suck were on the very early saws with the soft foam “breather”. I swap that for the later sintered breather. That said, haven’t seen a faulty tank vent on any of the 7 different 64/73/79xx I’ve had here.

 

[PA Dan]

If anything I found the tank vents on these saws to be better than what stihl or husky have on there saws. The only ones that suck were on the very early saws with the soft foam “breather”. I swap that for the later sintered breather. That said, haven’t seen a faulty tank vent on any of the 7 different 64/73/79xx I’ve had here.

Well not exactly sure what caused this issue. While @Glock37 and I were playing with my saw today it had trouble starting when hot. Not all the time but it did happen twice. When I got home and cracked the cap fuel sprayed. Got me thinking the issue may have been a tank vent?

 

[huskyboy]

Well not exactly sure what caused this issue. While @Glock37 and I were playing with my saw today it had trouble starting when hot. Not all the time but it did happen twice. When I got home and cracked the cap fuel sprayed. Got me thinking the issue may have been a tank vent?

That does sound like a tank vent or carb issue maybe? Think the vent is pretty cheap to buy.

 

[Wilhelm]

Tank vent doesn't let fumes out, it only lets air in - a pressurised fuel tank is a normal thing.

Mine like to have hot start issues if I shut them down right after a WOT run, I think it is due to vapor lock of the carb.

 

[mettee]

How could you tell that from the video?

It's got a squelch in the - 20 dB octave

 

[mettee]

Yes tank sees pressure

 

[mettee]

Dan ran a hd12 instead if the zama he's not telling you the truths yet.

Or was that a secret Dan?

@PA Dan

 

[Rob Stafari]

Mine will get finicky if I shut them right down after a hard run as well. I have learned to let them idle for a bit before shutting them off. Nate @fordf150 also sent me different metering springs with the rebuild kits for my 6421 carcass carbs to curb some flooding issues if I remember correctly. Although that won't apply if he has swapped carbs out.

 

[Wilhelm]

Same here!
Let the saw idle for a while after a WOT run before shutting down and she'll start back up without issues.
If I run out of fuel mid cut I quickly refuel and immediately start the saw back up to let her idle and cool.

It is not such a big issue when You get used to a shut down routine and/or have a couple more saws at hand.

If the vapor lock issue happens the saw will only start unwillingly with the trigger at WOT no choke and it will take numerous pulls.
Venting the tank or pulling the plug doesn't do anything positive IMHO.

 

[chipper1]

If anything I found the tank vents on these saws to be better than what stihl or husky have on there saws. The only ones that suck were on the very early saws with the soft foam “breather”. I swap that for the later sintered breather. That said, haven’t seen a faulty tank vent on any of the 7 different 64/73/79xx I’ve had here.

I had one that was shipped to me wouldn't run for crap, pulled the cover and for some reason pulled the fuel line off, she sprayed all over and in the house . I had called the guy and asked if he ever had a problem, prior to pulling the fuel line, he said never always fired right up and ran perfect. That was the only time the saw ever did it, I popped the gas cap a few times and no pressure at all .
I sort of like problems like that, but at the same time I don't.

 

[huskyboy]

Never had to do anything special to any, even the ported 7910 with the 460 piston swap didn’t have problems in 95 degrees logging with her. I’ve had problems with vapor lock and the tank over pressuring and overriding the carb spring on a 441 and 661 though. So I do know vapor lock/flooding problems can be aggravating. I had to increase the spring pressure in the carb because the tank vents built too much pressure in hot weather on them.

 

[chipper1]

Never had to do anything special to any, even the ported 7910 with the 460 piston swap didn’t have problems in 95 degrees logging with her. I’ve had problems with vapor lock and the tank over pressuring and overriding the carb spring on a 441 and 661 though. So I do know vapor lock/flooding problems can be aggravating. I had to increase the spring pressure in the carb because the tank vents built too much pressure in hot weather on them.

My 261cm v2 was acting up the other day after refueling, the 346 had no problems, sure my 2016 550 would have been fine too lol.

 

[Simondo]

Same bar and chain, maple logs and better tune!

Dan.
With the posts talking of running issues now.....
You say in this caption for the second vid that the saw has a "better tune" to the first vid.
What did you change ? as it seems to be "running on" a little coming down to idle in comparison to the first state of tune in the first cuts vid.

 

[PA Dan]

Yep I did notice that when I watched the video. I will check that out this evening. I didn't see it as much in the small log but it's hard to tell.

 

[Simondo]

Yep I did notice that when I watched the video. I will check that out this evening. I didn't see it as much in the small log but it's hard to tell.

I only mention it as I have experienced this on some of the Dolmar/Makita saws when tuning the L and H to get top RPM.
The L side seems to need to be ..Juuuust rich enough to help with a good snap back from high rpm and then the H side can be brought back a little for top end tune. A "mean to lean" ..ish L seems to not be to helpful from my findings. This info is based on standard and or , exhaust modded saws mostly.

 

[PA Dan]

I only mention it as I have experienced this on some of the Dolmar/Makita saws when tuning the L and H to get top RPM.
The L side seems to need to be ..Juuuust rich enough to help with a good snap back from high rpm and then the H side can be brought back a little for top end tune. A "mean to lean" ..ish L seems to not be to helpful from my findings. This info is based on standard and or , exhaust modded saws mostly.

Thanks my friend! I will try and correct as this saw will get a good bit of run time in the coming weeks!

 

[Simondo]

@PA Dan
In case it helps having the factory spec.....