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031av won't do...anything

RED-85-Z51

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It kicked on a prime last week after sitting over a decade, ive put on new impulse line, fuel line, new carb, new boot, scuffed the cylinder...

Has 125psi, which isn't ideal...but it should start.

Filed points, good, painful spark.

Cant pressure test because I loaned it to a friend for a few days, but, cylinder gasket is good, mag side seal is clean..dry. the clutch side...looks different.

It wont do anything, im just trying to get it to pop off spraying mix into the carb like i did before. Impulse is tight, boot is tight, can anyone verify this seal/bearing looks okay
55d7b780fd114094bd79ab5a1bd243dc.jpg


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Gaudaost

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It ran, or randomly burped? If the points are worn, doesn’t matter if you gap them correctly you’ll be running retarded. Spark too late means no combustion. Add to that low compression and possibly air leak all equates to a saw that isn’t in your favour for starting.
 

RED-85-Z51

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Might be onto something, its impossible to watch the carb while starting it, so i chucked a driver into my drill and turned the engine over...and it was spitting out the carb...bad. like not a misfire spit, but like...the compression was getting into the case.

I knew the top end was hurt, not, whatvi thought was bad, i scotchbrite scuffed it, felt good, looked good.

I took the top end back off and looked in with my phones camera and light and it showed me alot of imperfections i missed.

I ran it back thru with 400grit then 800...looks much better but I may be looking at some coin being dropped on a top end

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RED-85-Z51

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It ran, or randomly burped? If the points are worn, doesn’t matter if you gap them correctly you’ll be running retarded. Spark too late means no combustion. Add to that low compression and possibly air leak all equates to a saw that isn’t in your favour for starting.
Ran...for like 3 seconds.

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Gaudaost

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You asked what could be the cause of the saw not running, but you don’t even know when the saw is sparking.. I’d suggest that test the timing. You have nothing to lose and everything to gain. Once that’s ruled out that’s 5/6 things you’ve already done.

timing
Compression test
points gap
Fuel delivery
Spark

Air leak

Did you put straight oil down the intake to oil the internals? Or just 2 stroke fuel mix?
 

RED-85-Z51

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You asked what could be the cause of the saw not running, but you don’t even know when the saw is sparking.. I’d suggest that test the timing. You have nothing to lose and everything to gain. Once that’s ruled out that’s 5/6 things you’ve already done.

timing
Compression test
points gap
Fuel delivery
Spark

Air leak

Did you put straight oil down the intake to oil the internals? Or just 2 stroke fuel mix?
It was assembled with 2 stroke oil, then tried to start on 2 stroke mix gas.

The last saw with points was made years before i was born, ive worked on saws for 17 years and never had one with points. I doubt i even have the tools to test for it. 4 strokes with points are easy...this thing, the lobe is on the flywheel...

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Gaudaost

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All good, you may find that the assembly oil you used gave you a false reading of the saws compression. It may very well be 10-20 psi lower than what you got. Could be your running issue and the reason it burped originally (due to oil allowing for higher compression temporarily)

If you have a multimeter and want to check timing, let me know. I can run you through it.
 
RED-85-Z51

RED-85-Z51

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Back together, clean cylinder, new rings...140psi compression.

Its not spitting anymore.

Still not even trying to do anything, no smoke out the exhaust, nothing.

So, how do you check ignition timing, its got a heck of a good spark, now good compression, seals intact, new boot, line, a bit of sealer on the cylinder gasket just to be sure...and it shows me no signs of life...

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Gaudaost

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Seeing as the cam is on the flywheel it should have windows. Disconnect the points wire from the capacitor. Align the two timing lines (1 is on the outside of flywheel and the other is next to it on the case )
Feed the points wire through one of the windows.
Set miltmeter (mm) to resistance.
Connect one mm probe to points wire, other mm wire to ground. Gently rotate flywheel backwards until you get 0.01ohms (+/- .01) then forward until that turns to OL. That’s when your points are opening and the two markings should align. If not, adjust the ignition plate to correct the timing (normally held by 2 screws)

Also worth noting, a spark requires way less energy at atmospheric pressure. When it’s under compression is requires a heck more. If you have a bad coil, it may show spark via the plug when you ground it, but under compression, if there is a fault, it may not - set up an inline spark tester in this case :)
 
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