Duane PA 026

[ABarrick]

Appreciate the input.

I really think it’s a fuel issue. I have to check the tank vent as well.

It idled beautifully until it got hot. No issues on the high side.

I’m still out a full turn on the H needle, even with the jet drilled and the saw set at 15500.

Carb was new correct?

How sensitive are the adjustments? Does an 1/8 turn make a huge difference or is it negligible?

That's how my 260 acted with the HD34a (ms361) carb. Ran great cold, good idle, very snappy, good power. Make a few cuts and get it hot, then it would only idle for a few seconds then start to load up and die and/or have an off idle hesitation/bog. Not something I could tune out and find a happy medium hot vs cold. I assumed fuel pooling in intake but it idles fine with the 194 and nothing else was changed.

In my case, the HD was a parts bin carb I just put new diaphragms in. I wanted to try that particular carb as the Venturi is smaller and I thought it may be better suited to a 50cc saw. That model has an accelerator pump which I figured would help spool up. But, they are prone to problems and I ran out of patience with it so I shelved it til I find some more time to sort it out.

I have not been 100% satisfied with the overall manners of any of the 1121 saws I've swapped HD carbs onto but it really wakes them up in the cut so I keep going back down the rabbit hole.

 

[drf256]

I wanted to try an ms361 carb as well. I have an 039 carb here also. I’ve got 2 361 carbs en route.

Once hot, the idle got wonky. I could turn the L in and it would run better. Then I’d come out of a cut and the
L was too lean. Rinse/lather/repeat.

I tested the pop off with evaporated fuel in the bowl, so lots of oil on the seat. I’m postulating it gave me too good of a seal and therefore a higher than true pop off pressure.

I had to take more off the spring than common sense would dictate appropriate.

I actually did one thing at a time, for once. Taking this carb off is a bigger PITA than most.

What wasn’t videod was the saw with the stock #70 jet and just the pop off change. It didn’t change the screaming issue one drop. The jet opening did. #70 was .028 inch. The 68 is .030”. It still does the scream thing if you get too brave. It runs fine but fat at a 1.5 turns out H setting, it’s runable fat there, not slobbering.

My plan is too drill the jet to a 66, which is .032, and install another spring to restore popoff into the mid 20# range. I’m also gonna vac test the saw and check the plug while I’m at it. Why not.

The meteor has some of the typical meteor pin scratches on it. Machine marks still there. Compression still great.

The odd part is that the saw idled perfectly with no issues for a full 2 minutes before that vid with the L out 1 turn. . I’m guessing the carb got warm, the mix less viscous, and then the wet side overfilled and flooded the saw at idle.

 

[ABarrick]

Ms270 carb may be another option too. They use an HD with an accel pump. Not sure what model it is though.

 

[drf256]

A few more hours wasted. Same crap with more popoff and a bigger jet.

Saw runs perfect with a 194.

The idle issue has me stumped.

Gonna go through carb pile and see if i can find an HD with a smaller venturi.

 

[rattler]

A few more hours wasted. Same crap with more popoff and a bigger jet.

Saw runs perfect with a 194.

The idle issue has me stumped.

Gonna go through carb pile and see if i can find an HD with a smaller venturi.

Doc I got a hd17 if you need it

 

[Chainsaw Jim]

I'd set the v-stack and filter aside until you get the carb sorted out. It's an 046 carb, so there is enough fuel available. It isn't a stock appearing race saw so it doesn't even need a filter.
The main nozzle check valve, tank vent, or intake size in relation to the venturi should be the culprits here.

 

[Deets066]

Just put a nice ring of JB around the Venturi. The WJ 69 is pretty well mannered on the 024

 

[Deets066]

 

[drf256]

Had the carb out about 10X.

Too low popoff and likely bad seat. I polished seat with Qtip. Got it to hold. Ill add pics later.

Heres a way too long video before the idle issue sorted.

Heres the idle issue.

Heres the saw without the stumble, but still with the typical 026 bog.

 

[Onan18]

Had the carb out about 10X.

Too low popoff and likely bad seat. I polished seat with Qtip. Got it to hold. Ill add pics later.

Heres a way too long video before the idle issue sorted.

Heres the idle issue.

Heres the saw without the stumble, but still with the typical 026 bog.

Saw looks great bud!

Love the sig BTW.

 

[Wonkydonkey]

Love the vid titles, it says a lot of fiddling work gone into it.

 

[Duane(Pa)]

Chucky?

I think you just named your saw.

And when I hear Chucky, I think:
View attachment 124688

Awesome build thread Dr. Al.

Al was ready to "Chucky" him into the L.I. Sound

 

[Deets066]

It is aggravating, I can’t stand a bog when you grab the throttle

 

[Chainsaw Jim]

It sounds like you have some room left on the low circuit to get rid of the bog.

 

[Redfin]

What carb in the last vid?

 

[Wolverine]

Al was ready to "Chucky" him into the L.I. Sound

I'm currently working on an old Katana that is giving me fits. Wish I could chucky that sum beach!

This saw is starting to remind me of an old exotic Italian auto/motorcycle. Lots of fondling but when and if she runs, look out! Definitely the art of tinkering involved. I could live with an off idle bog if the top end is pure bliss

EDIT: My Ducati ('10) fuels like total crap below about 3,300rpm. Actually makes you look like a fool at times at low speed maneuvers. BUT, from 3,500 to 11k redline is like

It is what it is...

 

[Duane(Pa)]

What carb in the last vid?

All the same in those last three vids

 

[drf256]

What carb in the last vid?

Same. HD14

 

[ABarrick]

View attachment 126411 View attachment 126412 View attachment 126413

Videos?

 

[Deets066]

Videos?