361 Builds (one oddball)

[drf256]

It’s doing weird things.

I have nearly zero experience with limited coils.

I’m the first one to assume I did something wrong, but this tuning on the open port saw is just different.

 

[qurotro]

Hmmm. Dealer got a few new 361s here. Seems I should avoid them from all the difference between the good ole one and the new one.

 

[huskyboy]

Time to put the coil off the other 361’s on the 341 and see what’s up... interesting stuff doc.

 

[drf256]

Time to put the coil off the other 361’s on the 341 and see what’s up... interesting stuff doc.

That’s next, after the carb.

 

[Onan18]

Sounds like a bad main nozzle check valve in the 044 carb to me.

 

[drf256]

Sounds like a bad main nozzle check valve in the 044 carb to me.

Not sure bud.

A main nozzle check valve stops the metering diaphragm from pulling air instead of fuel into the wet side on idle from the venturi.

Shouldn't it be wide open at WOT?

Carb holds pressure.

 

[Onan18]

If the main nozzle check valve is bad it will allow the carb to pull way too much fuel amd load up. The thing to remember about most of these carbs is there is a certain amount of the high speed circut that is fixed. Even with the needle fully seated there is still a path for fuel to be pulled through and atomized. Part of the main nozzle check valve job is to regulate this bypass function. If it is defective then you basically have a flood limited carb.

 

[redline4]

@drf256 which of the saws is newer, the open or the closed port?

 

[qurotro]

@drf256 which of the saws is newer, the open or the closed port?

The newer ones. I went to dealer and see the 2017 361 with that open port cylinder. You can see the fin is different.

 

[huskihl]

Unfortunately, after all that work I can’t get the carb to lean out. The H screw is bottomed out. Had to throw in the towel for the day.

The carb was gone through and was pressure tested. It held over 30 psi without popping off. I have to pull it and play with it later.

With the H all the way in, and the L set at 1 turn out, the most I could get was 10,500. It’s fat as hell, unlike the other limited saw. The sound is unmistakable.

Doc,
Does the carb have an auxiliary main jet like the HD50 from a 461? If so, it could be too big. If you soldered it closed, the screws themselves may pass enough fuel. If not, you could could re-drill it a few sizes smaller

 

[huskihl]

^If in fact it's the fuel/air delivery that's the issue.

 

[Lightning Performance]

You found one odd duck. Maybe it was built from parts.

It has extended adjustment screws with cylindrical limiters that stopped on a cast boss that came out between them.

The walbro has the cast shroud with the recessed screws.

I didn’t catch the make of the 361 carb as it was going back in anyway.

If the coil isn’t limited it must be my tach. It’s still 4 stroking, but there is no way that’s 11500 to my ears at least.

I found one of those odd long adjustment screw carbs. Just the carb no saw to mate it with. Numbers said it was 341. I never messed with one. I have no interest in the 341.

Non of my 361's are limited. All are closed port.
My 362 must be tuned on the limiter or above or it just has no top end zing. It does get that lean idol-down after long cuts. A ported 046 did it yesterday. Easy to tune that out but it is now two turns out on the H.
I assume the small 361-2 crank gets hot and vaporized the fuel. I can live with that. It would burn down on my mill if not dealt with. Runs fine for tree cutting and bucking.

What is that odd little notch in that intake boot? AM part?

 

[drf256]

Well,

I confirmed a saw cant be leaned out if the choke flap is closed. The linkage got wonky.

That was the issue, but of course i didnt figure it out until i swapped out the main jet with a smaller one.

She is popping in the cut. I didnt advance the timing, but i need to confirm the prior owner didnt.

Also gotta put the damn bigger jet back in. Im 2 turns out.

Highest it saw was 15200

 

[RI Chevy]

Nice job Al!

 

[drf256]

Coil on 44 carbed saw.

 

[drf256]

New Open chamber coil.

 

[drf256]

 

[drf256]

Here it is with the 1300 coil. Hit 14500.

The coil in it was limited.

 

[RI Chevy]

Nothing wrong with that! Held nice RPMs. You could see saw breaking in each cut. Nice job.

 

[trooney]

Good job Al! See what a moment of clarity in your dementia can do!!! Thats the Al we know and love...