Thanks Gadge,
That's the best way to regard it, I'd say - a learning experience!
My learning appreciates your experience!
Did a bit more today, pulled the carby off totally, exhaust off and had a look inside. Pics to come. To do next is more degreasing/cleaning, pull the flywheel and have a look at the ignition.
The torpedo-type exhaust looks good, feels solid and intact externally so might give it a brush down, lick of rust converter and paint. I assume it's meant to be hollow on the inside? Did shear off the rusted bolt from the fixing ring when trying to remove the nut which was rusted on pretty solidly though.
Had a look inside both the exhaust and carby ports (yesterday) and all looks OK- no major gouges, rings there. But it's actually my first look at an actual used piston/cylinder in-situ!
What I did find was the exhaust port is half-occluded with carbon, the piston will have to travel a considerable distance more (~1cm) to expose the exhaust as a result. I'll have to pull it to dremel/grind the carbon off, a screwdriver's not working, besides I'll damage the piston.
Oh, should the rings be able to move up-and-down in theoir grooves?
More like some neanderthal with a hammer has been at work. That isn't the correct cup for a 2-stroke, BTW - that's a Kirby 4-stroke type. And it doesn't engage the lugs on the top of the flywheel, as the correct one would.
Thanks for the info, I had just noticed that the lugs were incorrectly engaged today. But there are three of them and three matching notches so it could have been matched if they'd paid attention. This would also have altered the height of the cup/drum, so Neaderthal is about right. Doesn't bode well for further investigation underneath, does it?
Does the N-21 plug sound right, are they available and what would be the gap? (Small engine manual says: consult the dealer)
Yep, that looks right for that engine [north-south orientation 160cc], of that vintage. They are available, but I'd use the equivalent NGK B4ES - better quality, and possibly easier to get from Autobarn, Bursons, Repco etc. Gap 0.025".
Thanks, NGKs have been a favourite of mine for years too so good to know they exist in this size!
Pics to come later...
