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Postby Chappy » Sun May 29, 2005 12:07 am

Mark,

I've owned and worked on 2 stroke engines for over forty years, and owed Lazairs for 25. I agree 100 % with what Shannon has told you concerning mixtures, oils, and especially honing (as in very, very little) in his previous posts to you. Go back and read them again so I don't have to write it all down here too!

Actually, I would like to add one thing. If you can't see the cross hatched hone marks and you do lightly hone the cylinder, finish up by washing ALL the left over grit left behind by the hone in the cylinder using hot water and detergent. Dry it, and then lightly oil to keep from rusting until you reassemble the engine. If you don't properly clean the cylinders, the left over abrasives can get all through your freshly rebuilt engine and cause severe, premature wear to seals, bearings, pistons and rings. What a waste!

Chappy
Chappy
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Postby lazflyn » Wed Jun 01, 2005 2:21 am

Thanks Chappy.

I flushed the cylinder with starting fluid at high pressure. Then I wiped the cylinder walls with a clean rag. Then I flushed again and set to dry. Then I lightly oiled the cylinder walls, piston, and rings. Then I reassembled the engine. Seemed to work out fine.

I did have an engine failure though yesterday. Everything worked out fine in that I was almost at the airport when it happened and had more than enough altitude. I could have shut the running engine off and glided down easily (thankfully). When I got my Laz back to the hanger I pulled the engine off. I thought the worst in that I thought it was rings seized or piston scuffing. I pulled off the exhaust and looked at the piston. Looked good so I then turned the prop over again. It would rotate freely, then lock up, then rotate freely, then lock up, etc. These intervals were probably at 30 degrees or so of rotation. Seemed like something was going on at the backend, so I pulled the flywheel. It was then that I discovered the problem: The four plates on the magnet (the ones spaced at 90 degrees apart from each other) had come off?!! I don't know why or how, but all four fell out as I pulled the flywheel off. Looks like I need a new flywheel which is fine (till I find out how much they cost $$), but not knowing why this happened is a little unsettling. Have you ever seen or heard of this happening before? I can't see any scaring or any other damage other than they just simply came loose from the magnet. Weird.

MarkDJ.
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Postby gdewsbury » Wed Jun 01, 2005 7:12 am

After having to tear down one of my engines twice in one season to make repairs because of damage caused by a decompression valve and finding the lower ring was seezed I decided to experiment with another oil to see if this could be rectified. Checked the other engine at the same time and found stuck ring. Seezed lower ring seamed to be the norm with the oil I was using. Ran the rest of the season on AMSOIL Synthetic. Over the winter I tore down the first engine to replace main bearings and seals since they had run since the rebuild in 2000. No sign of ring sticking or unusual wear. Opened up the second engine the other day to replace seals and bearings and this one looks great. Even after being stored for the winter there was still a light film of oil through out the inside. There is some carbon build up on the piston and head and exhaust port just like you would expect. Rings in this engine were replaced 2 years ago since I broke the stuck one trying to get it free. At that time I did a light honing to make sure new rings would seat well. I can still see the honing marks hardly changed from when this was done. Ring clearance is still within the tolerance specified for new ones after one and a half seasons. Not looking to bad for running 80:1 oil mixture.
P.S. No dark streaks across the wing and over the tail feathers.
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Postby Guest » Wed Jun 01, 2005 12:32 pm

Mark,

Contact RayJB60 as he recently replaced both his flywheels with the new ones required for the CDI units. He may cut you a deal on one AND save you some dollars.

George
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Postby Synthetics » Thu Jun 02, 2005 9:06 am

Glen,

I not a big fan of synthetics unless you use them prety well daily or a few times a week. synthetics do not seem to have the same moisture protecting properties that mineral oils do.

I never used Amsol products but have heard mised feelings on it .

I know a fellow in Chatham that sells Amsol and used to swear by it untill he had to rebuild his 582 to have it puke 50 hours later AGAIN !!

But with 2 strokes alot of difficulties are developed from the operator i have found.

80 : 1 mix -- good luck on 185s but i won't do it .

oil injected 2 strokes run about 50 to 80 to 1 on average and seem to be ok. But 185s is pre mix only. What oils brand did you have sticking rings with?

If it works for you --- keep up the good work. !!

Shorty

A great oil article
Synthetics
 

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