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Anyone had a set of CMI's with any age on them? I have a friend who was thinking of buying some, but we were told by a guy they have a bad habit of cracking...He said even the new ones with the cool callar crack? Thanks!:confused: :confused:

first i'm hearing of that I though it was really old stellings you stay away from?

I know the navy uses the CMI tube tops for the SEAL boats so i would think they are pretty tough.

Never heard a problem with CMI's. I had a set for 5yrs. Like Haveit said, the worst problem was that rope gasket.

When I sold the boat they still looked great.

I have heard of problems with Stellings and Bassett however.

DAVE

I bought a set of older CMI's for installation over the offseason.

Who knows what the BEST material is for the rope seals?

I hear folks mention fiberglass rope. What about some of the new teflon impregnated shaft log packing material? I guess its gotta be pyrex or some other heat resistant stuff, eh?

Comments?

My CMIs are 8 years old, with 300+ hours. No problem except that I can't keep the silent choice working.

I've never had good luck with the fiberglass rope seals, they always leaked after a few hours. I think it is the heat. I found some graphite rope at MSC, one day I'll give that a try.

I've already tried the graphite rope. The only thing it does is cause the engine compartment to turn black and put a "dust" all over everything when they start to leak.

Just my experiance.

DAVE

CMI will sell you the ropes, give them a call.

baja bailey,
I aquired several sets of the Navy Seal Tube tops. Some had pin hole leaks and I had them welded up. I cut the uppper tubes to make them fit my 25' Convincer with narrow exhaust outlets.. Since then I have reused the bottoms and bought new uppers for my 28' Checkmate.

As for the rope seals, I have had very good luck with the furnace door type of packing. I use a smaller dia of rope.. about 3/8" and the trick is to wrap the rope about the pipe several times and pack it into the clamp.. I did this the last time and I have no leaks.. the ones they sell need to be sealed at the ends. If you wrap four or five times.. there are no ends to seal...

I would buy CMI's again in a heart beat. You are advised to psi check them for any type of leaks before paying for them..

good luck

dick

I have all you guys beat!!!

6 years on my CMI headers
610 hours
3 sets of rope seals
no cracks

gotta love'em
would absolutely buy them!!!

Dan