So I am doing a top end on a Ms 660 I have. The story goes, I got a 660 on eBay that looked like it was all OEM but it was OEM parts on a china case with a china top end. As expected, it failed. Crank bearing took a ****, so I bought an OEM bottom end off eBay. No crank play and pressure tested with old china cylinder and it passed, so crank seals are good. I got a meteor P/C kit for it, and I'm having a helluva time getting it to seal at the base. I'm using Permatex Motoseal since I deleted base gasket. Squish measured at about .025 after base gasket delete. That should be a safe clearance right? I have read you really don't want much less than .020. Anyways, I keep getting air leaks with this setup, even tried using a new stens gasket, but still it leaked. My question is, there is a sort of lip around the cylinder base. Is it advisable to get a piece of glass and sand this lip off? If I do, I think it being flat will help it seal better. Will recheck squish after that, may need to use a gasket again, depending on thickness. I just don't want to sand this off if it turns out its there for a reason. Attached are a couple pictures I took of it against a straight edge. Hopefully you all can see what I'm talking about...TIA
Meteor cylinder not sealing at crankcase
- Thread starter Tnarg
- Start date
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Your cylinder base or case base is not flat and or square probability
From the casting
river of smoak
ArboristSite Member
it almost seems as though you could snap an ear off that base with it like that . I would try to flatten the base somehow . did they miss a step at the factory ?
Let me know if you end up getting a free cylinder. I'd take that one off your hands for the right price....
quattro.pilot
ArboristSite Member
I'd get some glass, gradations of fine grit wet-dry automotive sandpaper, little bit of cutting oil, and I would be taking off that lip and squaring up the base.
The base of the cylinder looks as if it was not machined after casting, the base is not likely square to the bore either as the base is squared with the bore during the turning/truing of the base.
That is going to be literal hell trying to sand that. Meteor plating is about .015” thick and takes 20 passes with the lathe to remove it. Motoseal is what I use, but it’s one of the thinnest case sealants made. Dirko red would seal that up no problem
T27_Scrench
ArboristSite Lurker
Yep. Dirko red is what you seek. I have used a belt sander like automotive machine shops use to re-face exhaust manifolds to shave down or true up cylinder jugs. You have to be careful and use gentle pressure. Measure the cylinder height before grinding and after. Use a gasket to make up the lost deck height. IIRC, there were two different gaskets used on 064/066 cylinders. A thick one and a thin one. Thick one was 1mm thick and thin one was 0.5mm. Use Dirko red, brakleen the mating surfaces, and let it cure a day before you run it.
any machine shop can deck that cylinder , just tell them how much can be cut off and use the base gasket.
Someone else had the same ring on the same cylinder not to long ago
Already done. Took me a about an hour and 3 pieces of 220 grit. And one piece of 500 grit. Lit up a bowl and sanded away. Coated with sealer and waiting to cure to pressure test.
Pressure/vacuum test passed. If I'm remembering correctly, I had about .035 squish. Could be tighter, but I'm not going to bother sanding more off that cylinder. Time to get some work done. Also, I should add that my eBay seller is sending me a new P/C kit to replace the unmachined one...nice. if anyone is interested in buying it or trading for a 372 xp P/C kit, send me a message. No farmertec junk please. Meteor or even Hyway will be a good trade in my eyes.
