OLYMPIC 251 POINTS

[SMOWC]

DOES ANYONE KNOW HOW TO SET THE POINTS ON A OLYMPIC 251 CHAINSAW I CHANGED CRANK SEALS, PUT SOME NEW RINGS ON THE PISTON AND NOW I CAN'T GET THE SAW STARTED ANYMORE THE SAW USED TO RUN BEFORE I DID ALL THIS, IT'S REALLY MAKING ME MAD

 

[Vintage Engine Repairs]

Hi, what makes you think the points are the issue?

 

[MacAttack]

Generally about .018" gap at the max opening is a good starting point.

 

[SMOWC]

Generally about .018" gap at the max opening is a good starting point.

Okay thanks I'll try that, what about the plate that screws in to the case it's slotted like you could advance or retard the timing

 

[SMOWC]

Hi, what makes you think the points are the issue?

I don't know what else it could be

 

[Vintage Engine Repairs]

I don't know what else it could be

Have you reset the carb? If the seals leak and the carb was tuned to compensate, it will now be way too rich with new seals.

Either way - setting points:

Turn the flywheel until the piston is at TDC where the points are open theirnfullest, adjust their gap between 0.3mm - 0.4mm

Then adjust the armature plate so that the points first break when the mark on the flywheel aligns with the mark on the case.

If you have a feeler gauge, use the thinnest one and insert it into the points gap, turn the engine over ajd the feeler gauge should slip out when the timing marks align.

That’s a “close enough” to get it to run. Ideally you’ll use a multimeter to fine tune when the points break and a dial indicator to set the timing.

See how you go

 

[SMOWC]

Have you reset the carb? If the seals leak and the carb was tuned to compensate, it will now be way too rich with new seals.

Either way - setting points:

Turn the flywheel until the piston is at TDC where the points are open theirnfullest, adjust their gap between 0.3mm - 0.4mm

Then adjust the armature plate so that the points first break when the mark on the flywheel aligns with the mark on the case.

If you have a feeler gauge, use the thinnest one and insert it into the points gap, turn the engine over ajd the feeler gauge should slip out when the timing marks align.

That’s a “close enough” to get it to run. Ideally you’ll use a multimeter to fine tune when the points break and a dial indicator to set the timing.

See how you go

Thanks I'm going to try that, i have no experience with points so this is my first try hope it works

 

[unknwn]

You cannot just depend on point gap for ignition of a magneto 2-stroke. The timing is likely -wildly- off.
Another aspect of the points that needs to be scrutinized is wear to the rubbing block that contacts the cam.
If you don't have degrees/thousandths-mm BTDC spec, and skill with the proper tools you will NEVER get the timing close enough to operate, not to mention flirting with overheating/detonation sorts of difficulties.
Many years in the motorcycle trade in those early years before electronic ignition took hold is where I source this wisdom.
If there is any carryover between points & electronic versions, and the models involved, I'm looking to find a new home for a 254 Olympic that is marked "electronic" on one of the engine covers.
It was dismantled due to a soft-seizure, and seems just about complete? So I'd figure it was running when relegated to a workshop's diagnostic bench.
I figured to see what it will bring in the "for sale/trade" pages of this forum before going the eBay way.
The whole thing would just need (have to!) to be worth my while to send it along to it's next owner.