250r head gasket

[ajd250r]

i have heard that the 01 yz 250 head gasket has the bolt pattern as the 250r head gasket just wondering if anyone has tried it

[Honda 250r 001]

any whats the point in doing this even if it does fit?

[ajd250r]

it is thinner then the stock trx head gasket

[dynofox]

Originally posted by ajd250r
it is thinner then the stock trx head gasket

Why not just use the cr gasket?

[ajd250r]

ive been reading a little bit and saw that some people have had trouble with the cr gasket leaking , i had a set of copped gaskets made and they will not seal to a changable dome i was just looking for another option

[machwon]

The CR gaskets work just fine as long as everything is up to par. The cylinder and head surfaces may need to be lapped on some granite. Otherwise the acorn nuts and copper washers help with the leaks around th cylinder studs.

[All250R]

I think YZ's have o-ring'd heads only.

[machwon]

Originally posted by All250R
I think YZ's have o-ring'd heads only.

I think you're right. They do have the same bolt pattern though.

[IcutMetl]

Just use the CR gasket or a thin portion from a TRX gasket. Coat the gasket in copper spray and let it tack up; assemble and torque to spec. If it leaks, you may have a flatness issue with cylinder or head- if this is the case, it should be an easy fix if it's only a little bit off. Remove the head, clean it well with carb cleaner. Cover the gasket surface with black permanent marker or Dykem bluing- use WD40, etc and 400 grit paper against a FLAT surface, and rub the gasket surface of the head with light pressure in a figure-8 pattern until the marker disappears. You can also do the same thing with the cylinder after removing the studs. If it requires any more than a few tries with light, even pressure, you may have to have the head/cylinder re-machined.

I scuffed up my head in exactly this manner, used a thin gasket with copper spray, and have had great luck.

[86 Quad R]

Originally posted by ajd250r
ive been reading a little bit and saw that some people have had trouble with the cr gasket leaking , i had a set of copped gaskets made and they will not seal to a changable dome i was just looking for another option

this may be your problem. with a head with removable dome that's designed for head gaskets, the dome surface is about .003" higher than the mating surface of the head and may be causing issues with sealing as a result. if i'm not mistaken, this type setup may require that you use the thicker oem gasket to compensate the differences in height. or you could machine the domes surface to get it closer to the heads surface. others that have had more experience with this may chime in.

[ajd250r]

so more or less i would be better off to just get a stock head milled down to what i want , i put a thin head gasket on it yesterday i put some blue permatex on it we will see how well that worked if it works at all

[86 Quad R]

what sort of compression are you after? what size dome are you currently using? it mat be possible to simply have the current dome milled a bit and go back with that using some three bond as a sealant. pm neil(C-LEIGH RACING
) here on the forums. he can set you straight on whats what with this. :cool:

[ajd250r]

when i had it built i was shooting for around 190 psi it has the flat top piston and an esr cool head with a 19 cc dome

[86 Quad R]

that sounds about right with that particular dome versus the flat top piston. yea! contact neil. he knows a lil bit of everything about all the different aftermarket heads thats been/come out over the years. he'll be a big help. :cool:

[ajd250r]

thanks cause this thing is about to drive me nuts

[machwon]

ajd250r, I do stock head rechmabering as well and have all the equipment to do any necessary machine work, boring, porting, etc. I fix the CT and ESR stuff to go faster as well. Let me know if I can help you out. Did ESR do the dome for a flat top piston or a crowned piston?

[ajd250r]

I have no idea who did the motor originally but whoever it was, was half a** because that had a stroker plate but not a stroker crank and the wrist pin backed out and scarred the cylinder walls so it had to be completely rebuild

[ajd250r]

Well I got it out and rode it yesterday after I put the thin gasket and permatex on it and I put the compression tester on it after I rode it , it came up to a 120 lbs either my gauge is broke or I have a serious problem

[86 Quad R]

have you previously been taking in coolant? that stuff will kill the rings and compression and doesnt waste its time doing it either.

[ajd250r]

Yes when I first got the motor back and got it broke in it started takin on water