Timing Advance s- When \ When Not To Do - Questions

[Stump Shot]

Guys, tell Santa you would like one of these come Christmas.

https://www.boschdiagnostics.com/diy/products/digital-timing-light

 

[Big_6]

Guys, tell Santa you would like one of these come Christmas.

https://www.boschdiagnostics.com/diy/products/digital-timing-light

$86.98 beans tyd

Sent from my SM-G900V using Tapatalk

 

[Terry Syd]

I mentioned Blair's work on two-strokes. Here is a link to his book -

http://www.dragonfly75.com/motorbike/2StrokeDesign.pdf

You can find a lot more than ignition timing in that book. Don't worry about understanding all the mathematics. The math is used to create new designs and applications. The meat of the information (which is what you want) is contained in the graphs and discussion of the tests.

Pay close attention to the information on 'loop saw', that is the results from a Stihl chainsaw.

 

[Dave pulsifer]

Example #2. @Greenthorn this is for you. As a rule of thumb a little timing advance always helps. Well I find this not to be the case on a 6100 dolmar. I built the 2 in the build thread on AS. I noted I didn't see any gains but both saws were brand new so some run time was required. I took one of them to hedgefest. I just didn't like how it sounded. I can't explain it but @WKEND LUMBERJAK knows what I be talking about. I swiped some of Matts tools and took the 5° advance I had put in it back out. Not only did it sound better it ran better as well. So I guess I'm saying it's a lot of trial and error. Lol.

The Makita ea6100 does not benefit from small timing advance?

 

[5155]

Wish I had found this post when dickering with fly wheel and coils the other week.

 

[Johnmn]

The Makita ea6100 does not benefit from small timing advance?

Try it, I have tried it on a few some like it some don't. But do a small advance

 

[Miller Mod Saws]

The Makita ea6100 does not benefit from small timing advance?

I’ll word it like this. On my ported saws. If you advance the ignition timing. The saw will start popping.

 

[CR888]

In my experience the timing is something you need to dial in and fine tune. Every saw is slightly different even the same models as there is a little play in flywheel keys etc. On some saws I've gained power, throttle response and max rpm by retarding timing a few degrees. Taking another's advice of advancing timing say 5° on said saw is only good if your saw timing is exactly identical to the guy who is offering the advice. Keys often have a few degrees play in them so my advice is TEST. Make small changes, see whats happening on the tach, throttle response etc. No one wants to 'retard' their saw...the word is hardly as exiting as 'advance' but its no different to rich/lean on carb adjustment screws.

 

[Dave pulsifer]

Thanks for the reply! Guys

 

[MustangMike]

So many variablies, may be slight differences in coils, your port timing and size and shape of your ports, ditto muffler mods and changes to the intake filters.

I also recently pulled a saw apart and found a "cocked key", so the saw did not have the timing advance I thought it had, and I assembled it real carefully (the fit of some of these Asian saws is not always perfect).

Timing can make a big difference. I did a muffler mod to my brother's 460 and the saw did not respond favorably at all. Then I advanced the timing by taking .020 off the key, and the saw woke right up.

Most Stihl saws seem to benefit from timing advances, but that is not true of many other brands or models (from what I have heard).

 

[Dave pulsifer]

So many variable, may be slight differences in coils, your port timing and size and shape of your ports, ditto muffler mods and changes to the intake filters.

I also recently pulled a saw apart and found a "cocked key", so the saw did not have the timing advance I thought it had, and I assembled it real carefully (the fit of some of these Asian saws is not always perfect).

Timing can make a big difference. I did a muffler mod to my brother's 460 and the saw did not respond favorably at all. Then I advanced the timing by taking .020 off the key, and the saw woke right up.

Most Stihl saws seem to benefit from timing advances, but that is not true of many other brands or models (from what I have heard).

I advanced timing on my ms261cm and it responded well.thought about trying it on my Makita 6100 but the buzz im hearing on hear is it dont respond! Well maybe it's time i try to port on it?

 

[huskyboy]

If it pops in the cut under a good load, good tune and good chain... you went too far and you don’t want to run it too long like that. You just have to know what to listen for, a crackling noise like static on a tv. Easy to back off the flywheel to stock. It can be a real bugger to do the cast in keys. A small file or a very small carbide burr in a dremel with care works for me. You want to try not to file on the flywheel taper itself, only the “key”. 1/4 (roughly .015 - .020) the key is a good spot to start. The cast in keys are usually larger than separate ones.

 

[huskyboy]

Advance isn’t always the answer though. I had a ported 361 here that popped in the cut with no advance. Stock timing. The saw has aggressive timing from the factory and when compression and heat was added... it actually needed slight “retarding”. I achieved this by gapping the coil a bit further with a slightly thicker business card. Popping gone. I feel like advancing timing is something that is trial and error. No generic answer.