# MF35 3 cyl perkins combustoin caps blowby



## shrievy (Jun 10, 2009)

I have a MF 35 1960 3 cyl perkins I totally rebuilt, started up and engine sounds great. I am getting blowby on all three combustion chamber caps. The old cap gaskets were circular, and the ones I replaced are shaped like the cap (copper). I took them off and put on new cap gaskets (shaped like the cap) and this time sprayed the copper gasket spray like you use on the head gaskets. I made sure it was all clean on the caps and the head, (surface and inside the hole). Torqued it all up to specs again and started, after about 30 seconds I got blowby on one and within a minute all 3 caps were getting blowby. Can anyone help me with this one, frustrating? thanks, John


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## moray (Jun 29, 2009)

Did you check that the caps are still flat?

It could be that they've been overtightened at some point, and are no longer flat.


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## shrievy (Jun 10, 2009)

*Problem solved*

There were two suggestions, one that they are not flat and have them milled just a bit to flatten them (both the caps and side of head). The other which I followed through with is paint the caps and side of head where they mate with aluminum paint, not spray but roll on or brush on out of a can. After a few days wait fired it up and just a hint of pressure leak out of one cap and after running a few hours all is sealed up and running great. John


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