RWJ4 Carb Settings on a stock 365 Special jug on an XTorq bottom end

[Moonshine]

Rebuilt a trashed bearings 372XTorq with an OE 365 Special 48mm top end. Saw starts easily, idles, accelerates great. Started at 1 1/4 L and 1 1/2 on the H. Have cut a about 3 cords of firewood with it and wanted to lean it out from the rich break in settings. Note I do not currently have a tach, tuning by ear only. The plug was black not oily or wet. Want to gradually lean it out so not too rich and create too much carbon on the piston top.
Today I moved the H in to 1 1/4. Saw came with the blue 13,300 limited coil. Cuts well, I'm hoping someone here is using this carb on an OE 365 special or 372 and can tell me if going to 1 1/8 on the H would be to lean with this saw. Appreciate any and all help.Thanks in advance.

 

[mdavlee]

Are you on the limiter yet?

 

[Moonshine]

Thanks MDavlee, not sure how to tell what happens when I hit the limiter without a tach.
Does it start cutting out or misfiring? Burrrying the 28 inch and skip chain in Big Leaf Maple 2 foot diameter with the H turned in from 1 1/2 a quarter turn t0 1 1/4, didn't notice any cutting out or misfire, saw revs good, and sounds smooth.

 

[mdavlee]

It will sound like 4 stroking sort of. It will be almost misfiring to get under the 13.3k

 

[Moonshine]

Just went out and pulled the plug, it is now a nice tan color.

 

[Moonshine]

Ok great then, if you were me would you leave well enough alone at 1 1/4 since plug is no longer carboned up and a nice tan, it is definately not white. There is a open box Hardline 8061-2 for $18, tempted to purchase it to confirm that I am not bouncing off the limiter or biting the bullet on the TT-20K, just wanted to see if I could do it by ear and plug color. My mix is 43:1 and non ethanol fuel.

 

[huskyboy]

Tune it in the wood, turn it rich till it burbles in the wood with light load then lean it till it stops burbling. That'll be tuned properly that way. If your plug is tan then your tune is probably good.

 

[Moonshine]

Thanks MDavlee and Huskyboy, my eyes aren't the best, but did feel that the plug was too black and I am going to use your inputs; got a little conservative and richened H out a bit to about 1 3/8 will cut some more wood and work on "tuning in the cut" as I think I am getting closer. Eventually CAD will put a tach in my hands to confirm and a non limited coil lol. It's just money after all. My ears can hear the saw 4 stroking (blurbles) while idling so should be able to start rich in the cut and clean it up with the H.

 

[mdavlee]

It won't 4 stroke at idle. Only wide open throttle out of wood.

 

[beaglebriar]

With the combo described in the original post I don't see how you could really find the proper tune without an unlimited coil or at least the higher limited coil from a 346. 13,300 isn't doing that saw justice.

 

[Moonshine]

Thanks for correcting my misunderstanding on idle, I am working on teaching myself the 4 stroking "sound" when unloaded in the cut. I have more to learn. Also appreciate the unlimited coil suggestion as well, my concern max rpm from Hisqvarna Workshop Manual was around 12.6.or 12.6 for the Special. I assume that with the unlimited coil, the saw could turn 13.5+ without being too lean.
.

 

[huskyboy]

Thanks for correcting my misunderstanding on idle, I am working on teaching myself the 4 stroking "sound" when unloaded in the cut. I have more to learn. Also appreciate the unlimited coil suggestion as well, my concern max rpm from Hisqvarna Workshop Manual was around 12.6.or 12.6 for the Special. I assume that with the unlimited coil, the saw could turn 13.5+ without being too lean.
.

My ported special liked 14k ish but stock they have restricted transfers compared to the 50mm 372. I'd tune it in the wood with either limited or unlimited and see where it likes it best. Is your muff opened up or stock?

 

[mdavlee]

365 will do 14k with a muffler mod only.

 

[Chainsaw Jim]

Here's an example of finding a safe tune. You can hear how the rpm went from too low on up way too high, and then back down to a good safe zone. The settings your are after will vary between different elevations, fuel mix ratios, and air conditions, so tuning by ear is usually the best way to go.

 

[Moonshine]

Ok, this is where saw is currently tuned.
I went ahead with the TT20K tach over the Hardline.
Idle 2800
High 12900-13100
At first I was hitting the limiter and gradually turned high speed out to get steady rpms.
Cleans up on the cut.

 

[huskyboy]

Ok, this is where saw is currently tuned.
I went ahead with the TT20K tach over the Hardline.
Idle 2800
High 12900-13100
At first I was hitting the limiter and gradually turned high speed out to get steady rpms.
Cleans up on the cut.

I would leave it there till you get a unlimited coil. Better safe and a bit rich than to play around with it. If it's cleaning up self feeding with a light load then your ok.

 

[Moonshine]

Thanks Huskyboy,
I have a stock 1998 350 that has a black unlimited coil as well as a Hutzl/Farmertec unlimited to interchange.
Pretty sure the 350 high spec is 12.5K max rpm.
Once the black coil is on what safe gains does that coil provide besides easier to tune at higher revs? Also easier to hear 4 stoking. Also want to put a 288 or similar outlet with screen on the side. One of my ongoing questions is why original max rpms were 12.5K on the 365 and on 372xp oe it was 13.5 since cases, bottom end same. Hoping to have that clarified.

 

[huskyboy]

Thanks Huskyboy,
I have a stock 1998 350 that has a black unlimited coil as well as a Hutzl/Farmertec unlimited to interchange.
Pretty sure the 350 high spec is 12.5K max rpm.
Once the black coil is on what safe gains does that coil provide besides easier to tune at higher revs? Also easier to hear 4 stoking. Also want to put a 288 or similar outlet with screen on the side. One of my ongoing questions is why original max rpms were 12.5K on the 365 and on 372xp oe it was 13.5 since cases, bottom end same. Hoping to have that clarified.

The black coil makes it easier to tune, not necessarily make the saw run better. My 350 with the 45mm topend and muffler mod/base gasket delete likes 13-13.5k. They don't rev as high as a 346 but they run good. If you look at the bottom of a 365 cylinder and a 50mm 372 side by side the transfers are smaller on the 365 cylinder. My ported one liked 14k but I don't have much experience with a stock one.

 

[Moonshine]

I know max rpms aren't everything but 4 stroking out of the cut is , if I go much richer on high side, I am 1 3/8 out from seated at the moment to keep it from dogging in the cut. Pretty sure it is close.
I am going to delete base gasket as that an easy mod with gains.

 

[beaglebriar]

With the limited coil it's hard to tell if it's actually four stroking or just hitting the limiter. I went to a 346 coil on my ported 372 xtorq for this reason also wanted to see if I could get a little more out of it of course. It's happy around 13'500, any higher would be a death sentence for the bottom end for sure.