Carburetors for the hr 80 in a hydro

[Bill Eilers]

Any good somewhat bigger carbs for the 80 hr. Must have low speed needel

 

[RaceMechaniX]

The best carb with a low speed needle for the 67/80 hr is an OS 9B closely followed by a stock hr carb.. If you want to flow a little more machine a bell mouth for the inlet of the 9B. See second picutre.

 

[longballlumber]

Tyler,

Where did you get the bell mouth for the 9B? Nice!

 

[RaceMechaniX]

Mike that is from an OS 105 HZ-R heli motor. They were sold separately as a replacement part. I just machined a thin plastic tube to shim to the correct diameter and fit perfectly.

Looks like Tower has them in stock: Tower hobbies

You can also 3D print these fairly easily too.

 

[Bill Eilers]

Thank you for the reply!! That picture comparison is what I need to make a decision. I've got two off an o.s. 70 helicopter eng.