Stihl 361 Junkyard Zombie Mutant

[bogieboy]

Am i reading the thread right that this is basically a 440 crank, 460 top end in a 361 case after a bunch of work? Seems a bit slow if thats the case... not trying to be a naysayer, i am just curious, because i have an 044 that i slapped a new piston in, and did some very mild porting to that seems way faster... also what length bar you running, and how sharp is the chain? It sounds kinda lean too...

My 044 is wearing a 20" in this vid, with fresh stihl square grind.

 

[drf256]

How’s that chain?

 

[Ketchup]

Am i reading the thread right that this is basically a 440 crank, 460 top end in a 361 case after a bunch of work? Seems a bit slow if thats the case... not trying to be a naysayer, i am just curious, because i have an 044 that i slapped a new piston in, and did some very mild porting to that seems way faster... also what length bar you running, and how sharp is the chain? It sounds kinda lean too...

My 044 is wearing a 20" in this vid, with fresh stihl square grind.

Definitely could be slow. That’s just some random chain I put a round file on. 25”, I think. But it’s dry knotty ash. It doesn’t cut fast.

Also could be lean. I just tweaked it by ear and put it in wood. It’s kind of a miracle it cuts at all.

FWIW. It should be somewhat lighter than an 044.

 

[farminkarman]

Definitely could be slow. That’s just some random chain I put a round file on. 25”, I think. But it’s dry knotty ash. It doesn’t cut fast.

Also could be lean. I just tweaked it by ear and put it in wood. It’s kind of a miracle it cuts at all.

FWIW. It should be somewhat lighter than an 044.

Ash definitely does not cut fast. It cuts terrible with an average chain, and so-so with a good square grind. Only chain I have in my arsenal that laughs at ash is Stihl RSP.

 

[bogieboy]

Ash definitely does not cut fast. It cuts terrible with an average chain, and so-so with a good square grind. Only chain I have in my arsenal that laughs at ash is Stihl RSP.

My muffler modded and timing advanced 194t doesnt mind burying the bar in dry ash... LOL stihl full chisel picco with a nasty hook ground in, in a dry nasty ash log...

 

[bogieboy]

Definitely could be slow. That’s just some random chain I put a round file on. 25”, I think. But it’s dry knotty ash. It doesn’t cut fast.

Also could be lean. I just tweaked it by ear and put it in wood. It’s kind of a miracle it cuts at all.

FWIW. It should be somewhat lighter than an 044.

I am thinking its lean by the bog after you started it..., also could be the chain needs a bit of help... i totally get the lighter than an 044, as i am eying up a scrap pile 029 right now to throw a 390 top end in... LOL but... would i need another saw in the 50-70cc range? Already have an ms280, a macullough mac 1-10, and the ported 044... with possibility of also doing a top end on an ms261cmb sitting in the pile too... not sure which one i want to build, if either of them

 

[Loony661]

I’m a little nervous to run this thing. It’s making a LOT of heat.

Keeping the top cover on should actually keep the cylinder cooler - keeping the air from the flywheel moving across the fins and out the other side. The fins trying to shed heat in stagnant air will actually reverse what you’re trying to do, IMO.

 

[Ketchup]

I am thinking its lean by the bog after you started it..., also could be the chain needs a bit of help... i totally get the lighter than an 044, as i am eying up a scrap pile 029 right now to throw a 390 top end in... LOL but... would i need another saw in the 50-70cc range? Already have an ms280, a macullough mac 1-10, and the ported 044... with possibility of also doing a top end on an ms261cmb sitting in the pile too... not sure which one i want to build, if either of them

That bog interests me. It’s more of a stumble. I did a cut before the video and after the cut it stumbled even harder. I thought it might be a death gasp, so I shut it off. It was nearly identical to running a saw out of fuel. I checked the tank. 3/4 full. I started it again and it idled fine. Then I shut it off again and pulled the top cover because the mount screw came loose and the cover was flopping around. That’s when I took the video. That throttle up was similar to the earlier symptoms, but more throttle cleared it and then it ran normally. Notice after the cut the way it chugs hard back down into idle. Could be tune, but felt more like a fuel supply or intake boot issue.

More cuts required.

 

[farminkarman]

My muffler modded and timing advanced 194t doesnt mind burying the bar in dry ash... LOL stihl full chisel picco with a nasty hook ground in, in a dry nasty ash log...

I was trying to give a vote of confidence that his chain could be making the saw appear to cut slow. It definitely seemed like the chain wasn’t biting well.

 

[Ketchup]

Keeping the top cover on should actually keep the cylinder cooler - keeping the air from the flywheel moving across the fins and out the other side. The fins trying to shed heat in stagnant air will actually reverse what you’re trying to do, IMO.

It definitely should. I worry that the 036 FW doesn’t move air as well as the 361 FW. In this situation I just removed the cover because it came loose. Then that I discovered the heat. The cover was near melting and I almost burned my fingers getting the plug wire off. That’s not right.

 

[Loony661]

It definitely should. I worry that the 036 FW doesn’t move air as well as the 361 FW. In this situation I just removed the cover because it came loose. Then that I discovered the heat. The cover was near melting and I almost burned my fingers getting the plug wire off. That’s not right.

Yeah that’s alarming hot.

 

[drf256]

Could just be lean. Chain looks like it’s not cutting vs saw rpm.

Was it the HD50 you converted? I haven’t had much luck with that carb personally.

Great build Caleb. Very nice. You’ll get it tuned in I am sure.

Anyway to weld up the 361 flywheel and recut the taper?

 

[bogieboy]

I was trying to give a vote of confidence that his chain could be making the saw appear to cut slow. It definitely seemed like the chain wasn’t biting well.

I wouldnt disagree with that....LOL a good sharp chain can make a huge difference, thats why i posted the vid of my 194... with a good chain ash can be cut fairly fast... wish i had videos of my 044 in that pile of ash, maybe if its still at my buddies lot later this week i can get out there and cut again...

@Ketchup i would take a real good look at the chain, and at the plug... hot enough to start melting the top cover is something wrong, wether its fueling, or a dull chain, or an ignition timing issue causing excess heat... if i remember right you are using an aftermarket coil? That could be part of the bog, and the heat, if the timing map is wonky...

 

[bogieboy]

440 crank is actually smaller diameter than 361. There may be seals out there that fit the difference but I just made some brass bushings. Kind of like the top hat on a 372.

View attachment 417807View attachment 417808View attachment 417809

Looking back thru at the build, with the bog, i would double check that your crank sleeves are still in place...i dont see any mention of retaining compound, and maybe a double check of seal diameter tolerances? The bog kinda sounds like an air leak a bit, i might be wrong though...

 

[Loony661]

Looking back thru at the build, with the bog, i would double check that your crank sleeves are still in place...i dont see any mention of retaining compound, and maybe a double check of seal diameter tolerances? The bog kinda sounds like an air leak a bit, i might be wrong though...

You might be on to something…

With the bog, and the excess heat, my opinion is that you’re also running a bit lean. Whether it’s an air leak, or just the carb tune.

 

[Ketchup]

Looking back thru at the build, with the bog, i would double check that your crank sleeves are still in place...i dont see any mention of retaining compound, and maybe a double check of seal diameter tolerances? The bog kinda sounds like an air leak a bit, i might be wrong though...

That’s the Green Mayonnaise.

The bushings aren’t perfect but I checked pressure/vac many times. I certainly will again. Hopefully I can fiddle more today. The chain is not dull, but a little raker adjustment might be the ticket.

 

[bogieboy]

That’s the Green Mayonnaise.

The bushings aren’t perfect but I checked pressure/vac many times. I certainly will again. Hopefully I can fiddle more today. The chain is not dull, but a little raker adjustment might be the ticket.

Gotcha...LOL i am used to seeing it in the bottle, not a mayo jar

 

[Ketchup]

Plug

Chips

Juice?


I cut some more today. It cuts strong but not fast. The saw started with the idle all wrong, so maybe there is a leak. I think my oiler is junk and maybe the exhaust should go up. I haven’t done a pressure test but that needs done. Working up to a list of things to do when I open it back up.

 

[Ketchup]

 

[Mastermind]

Plug
View attachment 421196
Chips
View attachment 421195
Juice?
View attachment 421197

I cut some more today. It cuts strong but not fast. The saw started with the idle all wrong, so maybe there is a leak. I think my oiler is junk and maybe the exhaust should go up. I haven’t done a pressure test but that needs done. Working up to a list of things to do when I open it back up.

What are the port timing numbers? And have you put a timing light on it to check ignition timing?