031 Won't Rev with Nova II Ignition

I just completely went through a Stihl 031. Compression is decent at 145 PSI. The carb is clean.

Here's the deal. The saw starts and runs great, but it just won't make any revs. It will only turn around 9000 RPMs. Plus, it doesn't have enough power to even make a cut. I'm thinking this must have something to do with the Nova II ignition I just put on it. I've read that it has to be wired on this model saw with the polarity reversed. So that's how I initially installed it. All it would do was idle. It wouldn't rev at all, none. I then reversed the polarity and it runs great, but it just won't rev over 9K and has no power. Could it be that I have the wrong flywheel? This saw had points ignition, so it's my understanding either the Nova II or brown Atom should be good to go on it. What gives?

When doing this type change over I have had to move the timing of the flywheel. I think I have turned it a little to counter clockwise. No for sure. Been a while but I do remember changing the timing.

lcso10 said:

When doing this type change over I have had to move the timing of the flywheel. I think I have turned it a little to counter clockwise. No for sure. Been a while but I do remember changing the timing.

Click to expand...

That's the first I've read of that. I thought they were supposed to be plug and play.

Some I have done was plug and play. Same with the 032. But some of both I have had to change the timing.

lcso10 said:

Some I have done was plug and play. Same with the 032. But some of both I have had to change the timing.

Click to expand...

Have you put them an a 031 specifically? I know the one time that I played with advanced timing, the saw lost lots of RPMs if you went too far. Counter-clockwise would advance it even further.

I did this with an 031, I changed out the flywheel to a electronic ignition version and reversed the polarity - works fine. I am thinking the solid state flywheel has the timing change already (different keyway location?)

sawjo said:

I did this with an 031, I changed out the flywheel to a electronic ignition version and reversed the polarity - works fine. I am thinking the solid state flywheel has the timing change already (different keyway location?)

Click to expand...

I thought the points flywheel was required. No? So you're saying I need a 031 electronic flywheel, PN 1113 400 1201? If that's the case, it would sure explain the problem.

One thing to think about--when the Atom module was used for the 031, you had to flip the wires--i.e. almost all saws had the blue wire to ground, but the 031 had the white wire to ground. I don't know if such a switch is possible with the Nova module.

Chris B.

cbfarmall said:

One thing to think about--when the Atom was used for the 031, you had to flip the wires--i.e. almost all saws had the blue wire to ground, but the 031 had the white wire to ground. I don't know if such a switch is possible with the Nova module.

Chris B.

Click to expand...

So which flywheel was used on the 031 with the brown Atom? Points or Electronic?

lcso10 said:

When doing this type change over I have had to move the timing of the flywheel. I think I have turned it a little to counter clockwise. No for sure. Been a while but I do remember changing the timing.

Click to expand...

+1, My dealer has been there, done that.

PM Rookie1, he is one of the best guy here when it comes to tinkering with 031's. He might have some info for ya.

blsnelling said:

I thought the points flywheel was required. No? So you're saying I need a 031 electronic flywheel, PN 1113 400 1201? If that's the case, it would sure explain the problem.

Click to expand...

Brad, I did this a few years ago and remember some senior members on this board saying (Andy) that I needed the solid state F/W. I just sourced it before I started and never tried the points F/W. Check the search, I seem to remember there being alot of info (and different opinions) on this subject.

Thanks for all the replies guys. It sounds like the points flywheel will work if you're willing to run keyless and index the timing manually. Otherwise, the electronic flywheel can be used with the key.

I have always used the points flywheel with out the key. 031 electronics were very rare around these parts. 031 points type still keep coming out of the wood works.

lcso10 said:

I have always used the points flywheel with out the key. 031 electronics were very rare around these parts. 031 points type still keep coming out of the wood works.

Click to expand...

I hate running without a key, but I think I'll play with it a little just to make sure that's what it is. Do you have any idea how far you moved it? 1/2 key width or what?

anybody with both F/Ws?
match 'em to determine the offset

I went out and did a little experimenting. I started by advincing the flywheel counter-clockwise about 1 key width. It was obvious I was onto something. I advanced it another 1/2 key. More improvements. I then went another 1/2 key to 2 full key widths advanced. This time it didn't get any faster and actually felt "wierd". So I backed it up to 1 1/2 key widths advanced. Before this, the saw would only turn 9,000-9,500 RPMs. Now it'll turn 13,400 leaned all the way out. I've got it set at 12,500.

This little experiment shows you just how much difference dialing your timing in can make. BTW, significant carb changes were required for each setting. This saw should now run great in the wood. If this were a work saw, I'd probably buy the electronic flywheel and use a key. But the flywheel seems to be holding well is only a collector piece for me anyway.

Thanks for all the input guys!

This is some good useful information in this thread.

Brad, thanks for sharing the solution. I've got some old saws in the que waiting to be rebuilt and I plan to eliminate the points on them. This thread might help me out; it is stuff like this that I come to the chainsaw forum for.



Mr. HE

Hddnis said:

This is some good useful information in this thread.

Brad, thanks for sharing the solution. I've got some old saws in the que waiting to be rebuilt and I plan to eliminate the points on them. This thread might help me out; it is stuff like this that I come to the chainsaw forum for.



Mr. HE

Click to expand...

You're quite welcome. I researched this before buying the Noava II and don't recall these timing issues. So it's definately good info to know.

Brad I headed out to the shop in a few, I'll look at this 031 and holler back at you.

I tried the Nova module. It sent quite a backfire out of both ends. Not fun. I went back to points because the spark was quite a bit hotter. I replaced the condenser with a low dissipation factor, high voltage (630V), around 0.1uF cap.

I think this is what I used:

WIMA
MKS4 series 630 V 0.1 uf 10 % L.S. = 15 mm

http://www.futureelectronics.com/en...0-4294918317-4294927021,Ny:True,Ro:0,Nea:True

better link:
http://www.mouser.com/ProductDetail...=sGAEpiMZZMvOcEq4GH1AAhexF5Ptk22/AogD0VKT928=

They are 48 cents each. You have to solder wires to them.


Brad. I have an 031AVE flywheel if you want it. You helped me out with my 031AV p&p experiment (still running strong), so I will mail it to you for free if you want.