Stihl 041 ignition questions

[JonCraig]

Was horse trading with a guy & got a pair of 041's not running. 1 is a parts saw, the other is complete but won't start. I've narrowed it down to it only getting spark at high RPMs. I have another 041 w/ the SEM ignition, and this one looks different. So I know it was originally either Bosch Electronic or points-type.

The previous owner installed one of those new modules, and I think that might be the issue. The saw DOES spark on my tester, but only at high rpms (my drill set to high speed). Higher than I could get pulling the rope by hand.

I'd like to know if he tried converting a Bosch Electronic ignition to a Nova module (which I've heard doesnt' work), or if it's actually a points system and maybe I can buy points & condenser and put this thing back together like it was from the factory.

So... the part number for the flywheel I have is: Bosch 0204 098 007. The part number on the coil is 2 204 211 052.

The stator plate (is that what it's called?) looks like it has spots for points, but I can't really see a nub on the crank where they would go. But maybe it's a small bump and I can't see it by eye?

Anyway... help a young pup try to get a saw older than I am up & running please. Here are two pics in case it sheds any light.

 

[alexcagle]

Was horse trading with a guy & got a pair of 041's not running. 1 is a parts saw, the other is complete but won't start. I've narrowed it down to it only getting spark at high RPMs. I have another 041 w/ the SEM ignition, and this one looks different. So I know it was originally either Bosch Electronic or points-type.

The previous owner installed one of those new modules, and I think that might be the issue. The saw DOES spark on my tester, but only at high rpms (my drill set to high speed). Higher than I could get pulling the rope by hand.

I'd like to know if he tried converting a Bosch Electronic ignition to a Nova module (which I've heard doesnt' work), or if it's actually a points system and maybe I can buy points & condenser and put this thing back together like it was from the factory.

So... the part number for the flywheel I have is: Bosch 0204 098 007. The part number on the coil is 2 204 211 052.

The stator plate (is that what it's called?) looks like it has spots for points, but I can't really see a nub on the crank where they would go. But maybe it's a small bump and I can't see it by eye?

Anyway... help a young pup try to get a saw older than I am up & running please. Here are two pics in case it sheds any light.

View attachment 517552 View attachment 517553

Strangely; sometimes reversing the Nova wires makes a difference. Might try that.

 

[hotshot]

So... the part number for the flywheel I have is: Bosch 0204 098 007. The part number on the coil is 2 204 211 052.

The stator plate (is that what it's called?) looks like it has spots for points, but I can't really see a nub on the crank where they would go. But maybe it's a small bump and I can't see it by eye?

Anyway... help a young pup try to get a saw older than I am up & running please.

The ground cam lobe is on the flwheel hub, just like the 031 & early 032 series.

 

[67L36Driver]

The 'electronic' ignitions produce a weak spark at cranking speed.
I normally get a 'no spark' condition by spinning the crank with my 1/2" drillmotor. 300 rpm.

IIWM (if it were me) I'd go back to points.

 

[JonCraig]

Thanks, guys. I'm leaning towards converting it back to points, too. So that plate that the coil screws to is definitely from a points setup? (The only other 041 I've worked on was an SEM solid state.) So all I need is the points themselves, condenser, and the cover, right? Am I forgetting anything?

Thanks!

 

[67L36Driver]

Thanks, guys. I'm leaning towards converting it back to points, too. So that plate that the coil screws to is definitely from a points setup? (The only other 041 I've worked on was an SEM solid state.) So all I need is the points themselves, condenser, and the cover, right? Am I forgetting anything?

Thanks!

It helps a LOT! if you can borrow the Stihl tool that fits over the crank and mimics the cam on the flywheel.

I borrowed one Mo.Jim has. He is my neighbor. Finest kind.

 

[JonCraig]

Well, turns out my flywheel was from a Bosch solid state setup, and the parts saw had a points flywheel on it. So I swapped 'em over and good spark at lower rpms. Put gas in tank and it ran.

Now to pressure/vac test, etc, but I think this one is gonna end well!

Thanks, guys!

 

[67L36Driver]

So, you have points or solid state on him?

 

[JonCraig]

Right now it's the nova module that he installed, but I put on the points flywheel (which, from my reading here, has a different magnet layout and is required for the nova to work right.). I'm guessing the prev owner just got the flywheels mixed up.

Still have to tune it in wood. If the timing feels off like many describe from using the nova modules, I'll switch it to points, but at this point I'll try it as is, seeing as I got the saws in trade so I'm $0.00 in them right now.

 

[JonCraig]

Got a loop of chain for the 18" Rollmatic ES bar and toyed with it tonight. Feels like it's running rich. Fires up easy, but lots of smoke & damp muffler, even with H adjust out only one turn. (I'm too chicken to go in any further.)

Could the timing being a hair off cause it to act like it's running rich? Feels like it should be revving higher, but then again it's old-school torque not new hi-revs.

Planning to take off the carb tomorrow and see where the metering lever is set.

 

[67L36Driver]

Open up the points a tiny bit. Wide = early, narrow = late spark.

Late spark is soggy, low power.

 

[JonCraig]

Still the Nova module. Might try advancing the timing as described in other threads.

If I get too pissed at it, I'll convert it to points.

 

[JT78]

Even after porting the one I just finished it only turns 10,800 and still four stroke. It runs really strong with the 20 inch bar buried in oak. So don't expect a whole lot of rpm. Just checking but did you rebuild the carb and check the metering valve ? That can cause a rich mixture.

 

[JonCraig]

I didn't; guy before me claims he did. (Yes, I can here you... that's why I'll do it today.)

 

[67L36Driver]

I have avoided using Nova modules as no one can say where the timing end up.

Removed a couple and hooked up the points after a polish.

 

[JonCraig]

Problem here is that the prev owner completely removed the points & condenser. :-/

Just took the carb off. Can someone smarter than me confirm that dude used the wrong diaphragm? The metering lever has the "hook", like where the diaphragm would slide into the arm. The diaphragm itself doesn't have the notch to accommodate.

He used the wrong carb kit, didn't he?

 

[JonCraig]

Follow up: Google search for the number on the carb was unfruitful. The only other number I see on the carb is a "2".

The metering cover says only Marvel-Schebler-Tillitson. Made in Ireland. R 1963.

 

[DND 9000]

Your carburetor is a Tillotson HS-138B. From the picture of the IPL, it seems to be the right diaphragm what you have, but I`m not exactly sure.

 

[JT78]

Not sure if it's the right one by pics but the rebuilt kit for it is a tillotson RK 21 you can also use the 23 and it will work also.

 

[JonCraig]

It had a 21 on it, I replaced w/ a 23 yesterday. It ran worse. (Only difference between the 21 and 23 is the different style metering diaphragm.)

I don't like chasing my tail, so I've bought the points & points cover to revert the saw back to points. From there, I'll be able to tell whether the problem is the timing or not. Will update when I get it all together.