I wiped out one of my cylinders with pistons in my new motor and not thinking I recoated it with assembly lube. Now realized that was a bad thing. I also turned it over a few times. How do I clean it all out? I know, stupid mistake

 

With piston at bottom of cylinder, use brake clean or intake cleaner (or a rag with acetone) to clean the cylinder wall the best you can. Apply a liberal layer of engine oil. Do this for both pistons that are at BDC. Turn crank 90 degrees, repeat with next cylinder pair. Turn 90 degrees, repeat, turn 90 degrees and repeat with last pair of cylinders.

Then turn 90 degrees and clean everything the rings pushed up and dumped at the top of the bore. Repeat the cleaning process one more time around. Second time, there's usually very little at the top of the bore except oil and you're as good as you're going to get.

 

Thank you. It�s only one cylinder. Not sure what the hell I was thinking

 

Then it's best to lube the other cylinder walls with motor oil before turning it, but the procedure is the same on that one cylinder. Clean, turn for a full cycle, clean.

 

It won't hurt anything unless you REALLY blobbed it up. Then it might foul the plug.

I personally prefer 2-stroke oil on rings, pistons, & cyl walls... burns MUCH cleaner than regular motor oil, and lubes just as well for the few seconds that's it's needed.

 

That is an EXCELLENT idea!! Terrific lubricant by reason of it working in spite of 50:1 gas dilution.
For the purpose here it would be perfect. Good thinking!

 

I use ATF on the rings and in the ring grooves, pretty liberally. I will use a little assembly lube on the piston skirts also. First startups, even with a primed oil system can use a little help, imo.

 

I used to use ATF too... worked fine as far as that goes, still use it on mains & rods when they're set up tight... but the 2-stroke oil seems better in the cyls

 

Never considered 2-stroke oil for cleaning and lubricating the cylinder walls but I'll have to do that on my next engine build.

Marvel Mystery Oil is like Frank's Red Hot to me. I put that - - - - on everything.

 

I usually use ATF as suggested by the machine shop I've gone to since I was 10 and messing around at my uncles shop next door. Over 40 years ago.

Used to dip the top of the pistons in it before installing.

But, the last engine I built I did use assembly lube on the cylinders and a little atf on the ring area of the piston, not nearly as much as I used to use.

What's supposed to happen by doing this? Runs great, burns no oil. Didn't foul plugs or O2 sensors.

And since two stroke oil is so popular, what about cooking oil? Two stroke builders used to use that. In fact some two stroke builders used to assemble the top end dry since it's not firing until it has fuel, which will provide the oil.

 

I think the 2-stroke oil is good here because it is engineered to burn relatively clean, plus I have a feeling its lubricity would be decent since it has to do its job in mixes as lean as 50:1.

 

I�ve built many 2 stokes as I toyed around with mx racing quads in the 80�s. I always assemble them dry. Did a lot of port mapping back then also to make the most of those dirty little engines.

 

Have you bolted the head on yet?