Head and Base Gaskets 95 RMX

[Masu]

Greetings all from Tokyo Japan!

I'm rebuilding the top end on my 95 RMX 250, (S model) it is a re-import from the USA.

I'm looking for the gaskets that Eric Gorr says Cometic makes for my bike. This would be a thinner head gasket (.25 mm, .010 inch) and a thicker cylinder base gasket (1 mm, .039 inch) Mr. Gorr talks about this mod in his Motocross and off road Performance Hand book, to increase the compression and change the port timing.

I cannot find an e-mail address on the Cometic site. The site has some gaskets listed for my RMX, the 2-cycle hi-comp top end gasket kit with a .012" base for the RMX is listed as #C7356. That gives me the Hi-comp head gasket I want, but not the thicker base gasket. I hope some one can provide me with part numbers so I can order these gaskets, as the bike is sitting in pieces now, and I really don't want to put it all back together without this last mod, as everything else is done to the bike, airbox, filter, carb, V-Force reeds, Chamber, silencer, suspension, 17" motard wheels, Oversized rotor etc. This is the last one to do, and everything Mr. Gorr has suggested has worked so well I want to take the opportunity of rebuilding the top end to do this last suggested mod. The guys in Japan have NO IDEA about what I'm talking about.

 

[placelast]

I e-mailed Cometic a year or so ago and did not get a reply. Perhaps the message did not get there but rest assured it should perform well with their complete top-end hiPer gasket kit as a set.

I do not have the text of his latest edition handy to comment upon.

I do remember talking with him about his verbiage and it needs some editing; I may someday volunteer to do so to help us commoners better understand the thoughs he is trying to convey.

This is what he told me: if you use the the kit then you'd essentially get similar results to his RMX head work. But if you go with his head work then do not use the Cometic hiPer gasket kit. I had him do the head work on mine (and mo-everywhere porting) because I did not know how long the kit would be offered. I couldn't be happier with the way it turned out.

He did not offer any thoughts on the base gasket, so I suggest you use the gasket that comes with the kit if that is what you are using elsewhere.

 

[Masu]

Thanks for the reply.

In the text Mr. Gorr says that the thinner head gasket and the thicker base gasket do wonders, the thicker base gasket changes the port timing, and the thinner head gasket, well it of course increases the comp.

I guess I'll just order the hi-comp set and see how it does.

I found out today from a local guy that there is two head gaskets offered for the RMX from Suzuki, the stock is 1.7 mm, then there is an optional 1.2 mm, but then he told me that there is a "Special" racing head gasket from Suzuki that is a 1 mm, I may go that route.

I also was wondering if using two base gaskets would do any harm?

Cheers!

 

[placelast]

No, the hot setup is the even thinner OEM '89 RM250 head gasket; all others being stock OEM RMX. The Cometic hiPer set mimics this at a minimum.

 

[DEANSFASTWAY]

Masu you ought to try calling Cometic a 800 752 9850 ask Katie to put you through to Jason in tech support and he will make just about any gasket you want he also makes them(basegaskets/headgaskets) in different metals with rubber lining (reuseable base gaskets) that wont slip or blow out with all different thicknesses. Theyll also make you alloy spacer plates and theyre really not expensive we have them make stuff all the time . Or email www.cometic.com. Good Luck and say Hello to GODZILLA for me .

 

[Masu]

Well the phone call would be kind of long distance, as I'm in Japan :)

That is why I wanted to go the e-mail route, I cannot find any e-mail addresses on the Cometic site, anyone have one? I guess I could try to fax them....

Cheers!

 

[SN22]

try scott@cometic.com or mscherer@cometic.com thanks

 

[Masu]

Thanks so much, I have yet to get any kind of response!

Cheers!

 

[Masu]

Jason got hold of me via e-mail after I faxed him. I'll be ordering my stuff soon, thanks guys!!

 

[DEANSFASTWAY]

Masu:does 1-800 #s work for you in Japan or is it only on the continent ? Just curious .

 

[Masu]

Dean, they do not work for me from here, they are only good for Canada and the US, I'm not sure about Mexico.

Cheers!

 

[Formula]

I run the 89RM head gasket. I also run the stock base gasket, what is the answer to using 2 stock base gaskets? My main concern is sealing things off. I have gasket material and could make my own but would rather buy 2 stockers. Only problem with stockers is that the base gaskets have a few small rubber beads on them for sealing certain areas, I worry that this could be a problem area when using 2.

Thanks.

 

[steve.emma]

i'm just wondering but can you use a rmx head gasket with the rm barrel? i know the rm seals witho rings but the surface of the head is flat so would it seal against the gasket? what im trying to achieve is a lower compression ratio on my rm to make it a bit more trail friendly.

 

[Masu]

The 89 RM was the last year with a "Head Gasket" after that they went to "O" rings. I think you would be better off having the head moded, change the squish band etc.

Cheers!

 

[Vincente]

I've got the cometic part #s for you.

1989 RM 250 C7063

1989 RM 250 hi-compression with .012" base gasket C7353

I used to have an RMX and I used the stock RM head gasket. That and the thinner base would have been even better I think.

Hope this helps........