Shindaiwa 500 run w/o oil.

[naturelover]

Hey all, first post! :msp_smile:

Have a 500 that was run without oil until seized.

Was looking to maybe fix it up, since it was the only one of the 4 the #($*$ thief didn't find..

Scored the piston and left some marks on the cylinder walls. Can't seem to get piston or cylinder new around here, but did get some rings for it. May look for used, but don't seem to have much luck buying off ebay.

I sanded with some 1500 grit to 3k grit sandpaper and got the cylinder smooth (used fingernail), but was afraid to take too much off the piston. Did get it pretty smooth though.

Has 90lb compression cold, runs until it gets hot, then it quits and can't get it started again. Checked compression right afterward, was down to 70lbs.

Here it is before teardown.

Cylinder and piston

Is the compression too low to run when hot?

Anything but a new piston and cylinder to fix it? I'd guess they are shot, but figured I'd ask anyway.

Anyone know of any good used ones, or a place to get parts if needed?

 

[naturelover]

Update!

Got it running again!!! :biggrin:

Still don't have any parts, and any parts I would possibly need are NLA (seals, piston, cylinder, exc.). Will have to spend some time looking around for those parts I suppose.

But while studying when playing around with it, got to looking at the ring gap..

Wrong size rings. :msp_blushing:

Thinking my new rings were the 451 rings.

Put the old ones back in, which looked okay after close inspection, and got it up to 120psi.

Runs good, but my homemade oiler gasket isn't thick enough, will have to order one. Got the carb adjusted till it was 4 stroking under load, (which was fun while pouring bar oil on the bar...) and went to lean it back and accidentally turned the L screw I spent some time at getting right. :msp_confused:

Speaking of... My couple of questions. :msp_tongue:

I put a carb kit in it a couple years ago, and was only run for a few minutes. Tore it back down and drained everything after thinking the compression was too low, but it seems that the L screw needs to be around 1/2-3/4 turn from seating to run right, is that okay?

I think the cylinder is okay, but still worried about the piston. Should I run it, or try and find a used one maybe?

Anyway, hoping it will make a nice compliment/backup saw for the 441. :msp_thumbup:

 

[alderman]

Specs say to start at 1 1/4 turns out on the low side, but if it revs and idles good I'd say good enough. Also might need to readjust when you get the motor good and warm.

If it runs good I'd probably run it, as your best bet for a cylinder or piston is somebody else's parts saw.

Check your rpms if you have a tach. These saws weren't built to be real speed demons and the old manual only calls for 12,000 rpms. I've run them a bit faster without any apparent ill effects.

I do run all my Shindaiwa's with a 32:1 mix. Whether this is good or bad, it has worked so far.

 

[naturelover]

Well Alderman, did just that. Decided to just go ahead and run it, though I did file on the piston some more.

Got an oil pump gasket, new fuel lines, circlips, and went to work on the cylinder.

As posted, got the cylinder looking good with some muriatic acid, and deglazed with some 400 grit sandpaper. I switched the rings from their respective grooves just to get them in different positions since they are the same rings.

Got it up to 130 psi.

Ended up buying a coil for it, but not sure if that was it or if I had the coil gap too close. It wasn't firing with the new coil either, contemplated and re-tested some things with a multimeter. Kept thinking it had to be grounding out or something, so for some reason tested resistance between the flywheel and coil legs, and wasn't getting much resistance. Noticed that as I pulled the coil away, got some more resistance, so I increased the gap to .01 instead of .006 and voila, had spark.

But I had it set at .006 when I ran it a few weeks ago, and it ran well. :msp_confused:

She did need some priming, but started and idled nicely. Cut some small bushes for a warm-up and noodled enough wood to get it tuned (am still gonna get a tach to test it just to see), but noticed it wasn't oiling very well, so back to the bench.

I thinned the oil (though it wasn't all that cold) and got it to dribble out the oil hole. Cleaned the bar groove, which was filled with gunk and reassembled. Still need to test it, but hopefully have that fixed. If not, will have to investigate some more.

So thanks to this site, now have a runner, and a nice backup for the 441. Am going to get a new 16" b/c for her (since I have the 441 running the 20"), and a new sprocket, though the old one doesn't look that bad. Will have to get a .325 file kit though, as I don't have anything that runs that.

Anyway, guess next on the bench is the old Wizard.

Here is some pics with it all nice and clean.

50 and 70cc saw plan!

And think I can now take the help icon off of my signature! Thanks again all!! :smile: