Timing Check

[RES]

One of my 020AVs has an aftermarket ignition module that replaces the points and condenser. I am not convinced that it is firing at the right time. Is there a simple way to check timing staticly?

 

[HiOctane]

I dont think you could do it static.

 

[havvey]

ignition

check the gap between it and the flywheel if it could be put back to points that would solve it. i got in to a similiar mess on mcculloch years ago. You might be able to degree wheel it wish i could help you more (at that time all we got was hours of fustration) went back to points and had a nice mac 55 :yoyo: umpkin2:

 

[Simonizer]

One of my 020AVs has an aftermarket ignition module that replaces the points and condenser. I am not convinced that it is firing at the right time. Is there a simple way to check timing staticly?

Do a dynamic test. Mark TDC on flywheel and crankcase with a white paint marker, remove sparkplug so it is easy to turn over, hook up a timing light to 12V battery, turn the saw over with a drill with a 1/2" chuck at about 300 rpm. If you don't have a degree wheel, divide 360 degrees by the number of cooling vanes on the flywheel fan. You will know how many degrees are between each vane and be able to make a close guess. Should fire about 12-14 degrees BTDC. Cheers.

 

[ShoerFast]

Do a dynamic test. Mark TDC on flywheel and crankcase with a white paint marker, remove sparkplug so it is easy to turn over, hook up a timing light to 12V battery, turn the saw over with a drill with a 1/2" chuck at about 300 rpm. If you don't have a degree wheel, divide 360 degrees by the number of cooling vanes on the flywheel fan. You will know how many degrees are between each vane and be able to make a close guess. Should fire about 12-14 degrees BTDC. Cheers.

What a Dufis

If there is a choice, and your going throught the trouble, why not set the saw up to run?

My Grandma would like 14 degs of advance , that saw will pull throught (start with) a lot more timing then that and rev and run better.

Set your marks and run it while testing the timing. If you run it at all speeds settings your would see if the timing / pick-up coil are braking down and bouncing the timing all over the place. You will find a lot more power at the higher settings,(watching for heat deposits on the plug),,running too hot or bucking the rope while the saw is hot is too far, but setting up the timing is the second cheepest way to get power after freeing up the muffler.

Kevin

I don't make the saws you use, I don't make the saws you use,... any better, I just make this up as I go.

 

[Simonizer]

What a Dufis

If there is a choice, and your going throught the trouble, why not set the saw up to run?

My Grandma would like 14 degs of advance , that saw will pull throught (start with) a lot more timing then that and rev and run better.

Set your marks and run it while testing the timing. If you run it at all speeds settings your would see if the timing / pick-up coil are braking down and bouncing the timing all over the place. You will find a lot more power at the higher settings,(watching for heat deposits on the plug),,running too hot or bucking the rope while the saw is hot is too far, but setting up the timing is the second cheepest way to get power after freeing up the muffler.

Kevin

I don't make the saws you use, I don't make the saws you use,... any better, I just make this up as I go.

He asked how to check the timing, peckerhead. I gave him an answer.

 

[RES]

Thanks guys for the info. I think the power drill method will work best for me since I can do it with the case off and the flywheel exposed. I can attach the drill to the clutch shaft.

 

[Lakeside53]

Thanks guys for the info. I think the power drill method will work best for me since I can do it with the case off and the flywheel exposed. I can attach the drill to the clutch shaft.

Be sure to take the plug out, but leave it connected and the body grounded. Obviously make sure you have no gas around. The is will make it a lot easier for your drill to turn the saw, and you can can turn it at higher speeds. Many saws with electronic triggers will barely, if at all, spark at 300rpm, Leaving the plug on makes sure the spark voltage is limited by the spark plug, and doesn't have to discharge internal to the coil.

 

[RES]

Thanks Andy. Awhile back I made myself a spark tester by soldering a wire with an aligator clip to the body of an old spark plug.

 

[Lakeside53]

Thanks Andy. Awhile back I made myself a spark tester by soldering a wire with an aligator clip to the body of an old spark plug.

That what I use, unless I going a running test, then I use the Stihl ZAT4.

The sparkplug/wire works the best.. but I grind off the grounding electrode and use a plug with the ceramic not protruding. Much easier to evaluate the spark as you are forcing it to generate a higher voltage to bridge the gap. You could just bend up the ground electrode vertical. Why? Ability to spark is dependent (amongst other things) on voltage and pressure... It take a lot less voltage at 1 atmosphere of pressure than 10 (which is why magnetos are pressurized on aircraft above about 15,000 feet, but that another story...) so, forcing a higher voltage at bench test is more realistic evaluation of ability to spark inside a combustion chamber.

 

[Simonizer]

That what I use, unless I going a running test, then I use the Stihl ZAT4.

The sparkplug/wire works the best.. but I grind off the grounding electrode and use a plug with the ceramic not protruding. Much easier to evaluate the spark as you are forcing it to generate a higher voltage to bridge the gap. You could just bend up the ground electrode vertical. Why? Ability to spark is dependent (amongst other things) on voltage and pressure... It take a lot less voltage at 1 atmosphere of pressure than 10 (which is why magnetos are pressurized on aircraft above about 15,000 feet, but that another story...) so, forcing a higher voltage at bench test is more realistic evaluation of ability to spark inside a combustion chamber.

Excellent Lakeside. You are in the top ten of intelligent people I have run across on this forum. Cheers.

 

[Lakeside53]

Excellent Lakeside. You are in the top ten of intelligent people I have run across on this forum. Cheers.

name the other 9 ...

o.k. 8, I forgot about you

 

[Mr.]

What weiner saw runs at that timing figure. Maybe one that was designed for leaded gas.

What timing figure do you set your 372 to?

Fred

 

[Simonizer]

What weiner saw runs at that timing figure. Maybe one that was designed for leaded gas.

What timing figure do you set your 372 to?

Fred

I don't know. I just kinda slap things together and hope it even runs. I don't really know stuff about things:greenchainsaw:

 

[04ultra]

I don't know. I just kinda slap things together and hope it even runs. I don't really know stuff about things:greenchainsaw:

WOW Simon that tell's us what we wanted to hear..You finally admitted what your all about..

 

[Simonizer]

WOW Simon that tell's us what we wanted to hear..You finally admitted what your all about..

Yup, grade 3 education, tools I bought from a pawn shop, scraping by on minimum wage,...things are tough. Do I fit in now? Do you think I will be popular on AS? You know, this is my only real concern in life.

 

[Mr.]

I don't know. I just kinda slap things together and hope it even runs. I don't really know stuff about things:greenchainsaw:

I fancy myself a romantic in a world of barbarians. So, noone's response surprises me, but....

If you knew what the figure was off the top of your head, I beleive you would have given it.

Fred

 

[04ultra]

Yup, grade 3 education, tools I bought from a pawn shop, scraping by on minimum wage,...things are tough. Do I fit in now? Do you think I will be popular on AS? You know, this is my only real concern in life.

Sorry to hear your story Simon.. Take a deep breath and relax you'll be ok...
Does that pawn shop give good deals on tools..

 

[Mr.]

Please correct my typos as I am too lazy to edit my post.

Fred

 

[Simonizer]

I fancy myself a romantic in a world of barbarians. So, noone's response surprises me, but....

If you knew what the figure was off the top of your head, I beleive you would have given it.

Fred

With porting dimensions too I suppose?