CR or TRX rad valve?

[Allison#51]

Can anyone tell just from the pictures if this is a cr or trx rad valve?




I'm guessing it's the cr because it has a pretty sharp angle and it's short just need someone to confirm that. It doesn't match up to my carb very well..

[rk88r]

Looks like a cr to me. I think the cr number is 0-2a and the trx is o-4a something like that. Is that a smart carb?

[dlunn]

It looks like a CR.

[2ndmoto]

Definitely a cr style. Trx has a longer neck. Boyesen made a 02A and a 02B for the CR. If I recall correctly, it is stamped on the side of the cage, in between the reeds, so you would need to remove the cage from the cylinder to see it.

The CR rad valves were designed for 38mm carbs while th TRX rad valves were designed for 34mm carbs. CR style definitely works better on modded trx cylinders

A 3/8" reed spacer will correct the alignment problem you are having.

Best regards
-Jason

[Allison#51]

Alright thanks guys! Another instance where I bought something that was listed incorrectly.. Lol Yeah it's a smartcarb rk88r. I guess I'll pull the reeds off and get a reed spacer I didn't wanna have to run one but I do wanna run the cr valve if they were designed for the 38mm carbs, I never realized they were that different other then the length and angle of the neck. I also need the boot to go from the reeds to the bigger carb. Maybe I could just get a radiator hose that's the correct size and make it a little longer..

[2ndmoto]

You can buy the boot from boyesen. They fit nicely into the grooves on the rad valve and carb.

http://www.boyesen.com/rad-valve-replacement-boots-10.html


Best regards
-Jason

[udontknowme]

spacer might not be  a bad idea. some them rad valves sit so far in i think they hinder the boyesen ports

[JesseA420]

i know for a fact stock cr intake is at such a sharp angle it runs the carb straight into the frame rail. if this has the same angle, it will take more than just an intake spacer to make the carb point to in between the frame rails. i just sold it and got the correct trx intake.

[Allison#51]

i know for a fact stock cr intake is at such a sharp angle it runs the carb straight into the frame rail. if this has the same angle, it will take more than just an intake spacer to make the carb point to in between the frame rails. i just sold it and got the correct trx intake.

Yeah I think your right. I wish we had more options for carb to airbox boots and it wouldn't be as difficult to get everything to line up.

[2ndmoto]

I ran the rad-02b with a 3/8 spacer into a 38mm pwk on both an OEM and prox cylinder. This was on stock frame using an 89 airboot and stock air box. Didn't have a problem with alignment.

I have never tried running the OEM CR250R intake manifold, which is what I think Jesse is referring to.

Best regards
-Jason

[Allison#51]

I ran the rad-02b with a 3/8 spacer into a 38mm pwk on both an OEM and prox cylinder. This was on stock frame using an 89 airboot and stock air box. Didn't have a problem with alignment.

I have never tried running the OEM CR250R intake manifold, which is what I think Jesse is referring to.

Best regards
-Jason

Did the airboot rub on the frame though? Thanks

[2ndmoto]

It was years ago and the only thing I have left of the setup is the airboot. I can look an see if it is worn from rubbing on the frame...however that will have to wait until this weekend. I dont recall that ever being an issue.

But, thinking more about it, I am pretty sure it was a 1/2" reed spacer



Best regards
-Jason

[2ndmoto]

Found the airboot. I don't see any wear marks on it. Ran a few seasons with this setup. I think you are good.

Best regards
-Jason

[Allison#51]

Found a trx rad valve (04A) so I did some comparisons with my cr valve (02). Hopefully this will clear some things up

[Allison#51]