Going back inside the 041 super

[Chainsaw Jim]

I'm going to try a new recipe on this 041 I built last year. So far I've added a boost port to the cylinder that resembles the poulan 655bp and windowed the piston to let it work. I deleted the base gasket with no squish or base work. I enlarged the intake and exhaust, but did not raise any of the ports.



This time I'll be lowering the cylinder and changing the ports up a bit..along with a carb mod.
Here's a clip of how it runs at the moment:

If reconfiguring the ports and carb don't make it more ear friendly then I'm just going to pipe it.

 

[Mark71gtx]

How much different did it run once you completed the mods you have already done?

 

[Chainsaw Jim]

I think most of the gain came from disabling the flood limiter on the carb. Though it did gain on the throttle considerably with the other mods. But overall not a huge difference.

 

[Mark71gtx]

I had two. Technically I still do, but both are claimed at this point. One FB and one AV. They seemed like decent saws, but no wow factor.

 

[Chainsaw Jim]

They seemed like decent saws, but no wow factor.

That's exactly why I decided to do this and the 075 build.

 

[sawfun]

Good thread.

 

[Stump Shot]

Nice job on the saw there Chainsaw Jim, Another thing that hinders these old saws is the point style ignitions. I converted a Farm Boss to electronic ignition, unbeknown to me the rev limiter quit working before I repaired the ignition. Holy cow did that thing cut like mad. Impressed me so much I got an AV I had to running, and no wow factor as the rev limiter kicks in just when it starts rolling along pretty good. That saw is in pretty nice shape so I decided to leave it stock. I do have another trashed FB in the junk pile, hmmmm...

 

[sawfun]

My buddy has an 041 super and while it had good 70cc torque, it lacked rpm thus "wow factor" to me. Still it cuts wood great just slower than most other 70cc saws or its era.

 

[Chainsaw Jim]

The 041 super is listed at 3.7hp. It's a good example of a saw with high torque and low hp. The 372xp and 044 are both rated at 5.4hp and though they cut faster, the 041 can run a longer bar. I figure if I can bring the hp up to around 5 and keep the torque then it'll be one hell of a fun saw.

 

[Chainsaw Jim]

It took longer making the cutter than it did cutting the squish. Now it's base cutting time.

 

[Chainsaw Jim]

I had to take .067 off the base.

 

[drf256]

I strongly approve of this thread .

I love the way you think outside the box Jimbo. This is GOOD stuff.

I'm not sure how that boost port will help loop scavenging though. I'd keep the top entry angle really flat so it shoots up the "intake" wall.

 

[Chainsaw Jim]

All put back together now and was just finishing up with the carb until I had a peek at the time. It'll have to wait until tomorrow.

 

[Chainsaw Jim]

I think this thing is now better suited for the application.

 

[Chainsaw Jim]

Here's a run after initial rebuild. I still want to try another carb and a different muffler. There may as well be no muffler since for one..there they're so small, then the opening on this one is in line with the end of the tube for more of a straight non muffled pipe.
But the port timing and carb change did in fact change the tone and make it considerably more tolerable on my ears. It is no longer painfully ear bleeding loud and I didn't touch the muffler.
The oil tank ran bone dry a cut before the one in the clip. It wouldn't even make another cut after that with the chain starting to bind up on the bar. I would have refilled the tank to re record the video but I'm fresh out of bar oil.

 

[drf256]

Look damn good!

 

[Chainsaw Jim]

I tried to put a little run time on it before showing the video a few posts above and ended up showing it running with no bar oil. I just noticed I had a clip of the first couple cuts before it went dry so here's that...