12254-KS7-881 head gasket

[dynofox]

I've had some conflicting reports as to which head gasket the 12254-KS7-881 is from. Some say it is a CR gasket but I found this part number by looking up the '86 ATC 250r on Service Honda's parts finder. Is this gasket a 3-piece design? How much would it raise my compression? Currently have 170lbs with a stock trx gasket. I am looking to bump the compression slightly to increase low end but can't go too high as no place locally sells race fuel so I'm stuck with using 91-94 octane unfortunately.Thanks!

[addictedtomud]

Yes, this is the 86 ATC head gasket - it is pretty thick, definately not a cr type thin gasket. In fact, it may even be lower compression than a stock TRX, but I am not sure about that. Others on here will know...

[zedicus00]

if it is truly an atc gasket it will be a bit thinner then the trx gasket but not much. honestly if you can get 94 octane you chould be safe to 200 psi. try cutting it up. you could run the 2 thin pieces together to get you a little bit more spacing.

dont run it hard and do some testing, make sure you not knocking or pinging but that should get you a good power increase.

[Rich250RRacer]

It may be the correct gasket from an ATC, but that's only because it was superseded from the original ATC part number. The KS7 in the part number indicates it is CR in origin. The 86-88 CR250 model ID is KS7. The first few years of the HPP (power port) motor used a thicker gasket, later HPP motors used the single layer thin gasket.

[dynofox]

Originally posted by Rich250RRacer
It may be the correct gasket from an ATC, but that's only because it was superseded from the original ATC part number. The KS7 in the part number indicates it is CR in origin. The 86-88 CR250 model ID is KS7. The first few years of the HPP (power port) motor used a thicker gasket, later HPP motors used the single layer thin gasket.

Thanks for the reply. :)

[bloodswet&gears]

i bought a 12254-ks7-881. looked it up for an 86 cr250r. thought that it would be thinner than the one in my trx gasket set, but they were both 3 piece. they were the same thickness. i wanted to use something thinner but i bolted one on anyways.

[2-330s]

you need the 88 cr 250 gasket