Question about crank case seals during reassembly after splitting a case - Dolmar 6421

[sevensandeights]

Can I just manually hold the decomp in the "out" position?

Anyone know the thread size for a Dolmar decomp valve or have a link to the proper plug? All I've ever read about it is that they cause problems so I have no issues blocking it off.

 

[hacskaroly]

Can I just manually hold the decomp in the "out" position?

Yes, you should be able to do that, if it still leaks, then there might be something (carbon) between the decomp and its socket that needs to be cleaned out.

 

[huskihl]

I have actually never done a vacuum test where I couldn’t hold out on the dcomp and not be able to seal it up. I could see where carbon could get in there though and make it not seal. I’d think the carbon could be cleaned up well enough by running it through an ultrasonic cleaner or soaking it in carburetor cleaner for a while and working it in and out in a twisting motion.

Any standard decomp plug will work