Posts Tagged ‘os91hz’

OS91HZ-R (Regulated) Almost Ready

February 8th, 2010 2 comments

First production is scheduled to complete early March.

It looks like O.S. is getting very close to releasing the new 91 HZ-R engine, which is basically a stock 91 HZ that will ship with the new regulator system that I have been testing since June of last year. This regulator works with crankcase pressure and delivers a very consistent run from beginning to end, it also improves performance as well as mid range response. It is unknown exactly when it will be released in the US, but I am guessing sometime in the Spring. It will of course be available in Asia first and Iā€™m sure a lot of people will order it directly from an Asian shop

It is also unknown at this time, but apparently O.S. will sell the carb by itself, so that it can be installed on any O.S. 91 HZ motor or even on an Align H motor. More info about this system here:



  • This is a main fuel tank pressurized regulator system integrated version of the 91HZ.
  • Newly designed 61E Carburetor integrated with a regulator surely regulates pressurized fuel. As with other 91HZ engines, it features twin needles which can adjust hovering and high speed flight independently.
  • Regulator is located at a place where heat does not suffer and access is easier.
  • The system ensures stable fuel supply irrespective of rapid model attitude and G changes.
  • The system does not use muffler pressurized fuel system which requires needle adjustment according to the change of
    muffler pressure.


  • Displacement : 14.95cc (
  • Bore : 27.7mm (1.091in)
  • Stroke : 24.8mm (0.976in)
  • Weight : 625g (22.05oz)
  • Output : 3.4ps/15,000r.p.m.

OS Regulated Carb

OS91HZ Manual

July 13th, 2009 No comments

…because I couldn’t find one anywhere on the net, here’s a scanned copy šŸ˜›
OS 91HZ Manual

Categories: General Discussion Tags: , , , ,