CMB 67 Goldhead question

[Chuck Sturgis]

Hi I am new to nitro. I have a 1/8 scale hydro I am building and I would like to know the difference between the Cmb 67 Goldhead and the Green head engine. Also what pipe works well with these motors. Thanks Chuck

 

[Hydro Junkie]

Not sure about what the difference is, but in the general forum there is a thread or two on the subject. I do remember reading that parts are hard to get for the gold head, so get the green head and an OS 9B carb for it. I've seen very few scales that don't have that set up in them now days. My boat has the same set up as well. I would talk to allrc here in the forum as he and his son are 1-2 in the R/C Unlimiteds points race. He can set you up with what you need as well as answer many of your questions

 

[poolschool]

Just interested, but what's the difference between the 9B and the CMB carb with the 3rd channel needle. I believe that both these are a 12mm bore?

 

[Hydro Junkie]

Just interested, but what's the difference between the 9B and the CMB carb with the 3rd channel needle. I believe that both these are a 12mm bore?

The 9B is much easier to find the right setting on compaired to the CMB. If I hadn't heard and seen that from several of the guys in R/C Unlimiteds, I wouldn't have shelled out the $93 for the OS. either. Must be something to it since all of the top boats run a CMB/9b setup

 

[randoon]

The greenhead has a different bore/stroke ratio and better fuel trnsfer to the ports which makes faster out of the box and you can't get the same out of the yellowhead. Add to that the availability of parts and it's a no-brainer. The OS9b is bullet proof and easy to get the right set up like Hydrojunkie said.