CR Head Gasket Jetting ???

[ERBE]

Putting a CR 250 Head Gasket on a 86 TRX 250R Stock Porting , FMF pipe, how many jets sizes should I go up?? change teh needle ond the go up the pilot.

[Scott-300ex]

Prolly stay the same, I did on mine and it runs great and the plug is the correct color.

If anything you'd go down on jets cuz it would be a smaller chamber and you would only go down like 1 size.

Now if you just added your pipe along with it, maybe up 1 size. But do some plug chops and I bet you'll be fine right where you are right now.

My advice, keep it the way it is.

[ERBE]

Originally posted by Scott-300ex
Prolly stay the same, I did on mine and it runs great and the plug is the correct color.

If anything you'd go down on jets cuz it would be a smaller chamber and you would only go down like 1 size.

Now if you just added your pipe along with it, maybe up 1 size. But do some plug chops and I bet you'll be fine right where you are right now.

My advice, keep it the way it is.

Were adding compression, you have to go up on the mainI was told from a builder just a bit ago, go up 3 sizes , go up 1 on the pilot, and check my needle may need to go 1 size richer, this is based on the CR compression is like adding an extra 20 lbs I thing stock is 155 to 160 jumping to close to 180

[fireburns99]

you'll need to go up at least one jet size on the pilot. The more compression the more power down low. As far as the main jet, i would think it should stay pretty close to the original jet size.

[Scott-300ex]

Originally posted by ERBE
Were adding compression, you have to go up on the mainI was told from a builder just a bit ago, go up 3 sizes , go up 1 on the pilot, and check my needle may need to go 1 size richer, this is based on the CR compression is like adding an extra 20 lbs I thing stock is 155 to 160 jumping to close to 180

Up 3 sizes?:huh

Good luck with that.

You don't add a CR head gasket then jet it to CR specs.