Ronie's 361 kit saw

[huskihl]

*frenching slacker

Yes

 

[srcarr52]

I leaned the saw out to 14,850 WOT and it was a hair bit quicker but now it's doing that burbaling thing after the cut like my 660 clone did, but even more.

@srcarr52 would you mind listening to it and tell me if you think this one has the same problem as the other saw with the pop off or do you think it's something else?

It seems to be just a tad lean there. It slowly returns to idle as the carb and intake cool off.

 

[Ronie]

I’ll cut your other one today. Just been busy

I'm in no hurry, I've got this other cylinder to try first.

 

[Ronie]

I started back on the 361 this afternoon and decided to go straight to the OEM cylinder. I got it tore down, base cut and started laying out the ports, I'll start grinding on it tomorrow. The exhaust ended up at 103 after the base cut, wish it was lower but that's where it's at with .018 squish. Intake will just be squared up and widened, the transfers staggered. After I get the cylinder done I'm going to put an OEM 440 oiler and an OEM 390 carb on it.

 

[Ronie]

Forgot to add that huskihl took, .045 out of the band for me, I didn't want to risk messing up the cylinder.

 

[huskihl]

Shiny band and walls

Scotchbrite ftw

 

[LoneOak]

What is the purpose of the little hole under the intake?

 

[Ronie]

What is the purpose of the little hole under the intake?

I read somewhere that it's to let pooled fuel drain into the crankcase but I'm not sure.

 

[LoneOak]

with the shape of the opening in the intake, I could see why that would be necessary.
I was assuming that it was to provide additional lube for the piston skirt.

 

[Ronie]

Got the cylinder finished up and just need to wash it and put it on. I screwed up a little trying to get the corner of one of the transfers next to the exhaust and went to far but I think it will be ok.




.

 

[Ronie]

I got to give it a try this morning, no wow factor but it runs good for a 60cc saw. This after noon I'll put a sharp chain on it and see if I speed it up a little. First video is oak and the second is yellow pine.

 

[Ronie]

Retuned it and put a sharp chain on it, ended up at 14,100 WOT RPMs. So that's it for this one.

 

[Maintenance Chief]

So you have a bigger carb on it?

 

[Ronie]

So you have a bigger carb on it?

I put an OEM 390 carb and a 440 intake on it.

 

[Maintenance Chief]

Do you think you might get better torque and a stronger fuel signal from the factory sized carburetor? Maybe at the cost of some vroooms.

 

[Ronie]

I was just comparing this cylinder times with the aftermarket one and the aftermarket one was 4 seconds faster. I'm going to try leaning it out some more and see if it get's any quicker.

 

[Ronie]

Do you think you might get better torque and a stronger fuel signal from the factory sized carburetor? Maybe at the cost of some vroooms.

Maybe, I'm not sure.

 

[Maintenance Chief]

Maybe, I'm not sure.

I've used a smaller carb to draw a stronger fuel charge on other motors so just an idea.
Even a McCulloch sp125 uses an sdc style carburetor even though you could probably get away with a HT syle 880 carb.

 

[Ronie]

Thanks for the tip, I lean it out and I'm uploading a video to youtube now.

 

[Ronie]

So the quickest time leaned out was around 12 seconds, about 3 or 4 seconds quicker. I need to work on the tune some more.
Just wanted to add that it started out at 14,950 WOT in the video.