OS .91HZ-R

[@DashzRight]

I love people that have all this equipment and seems to know what they are doing. Without sarcasm.

[@drummerdeacan]

Great video Bill. I enjoyed it. Love your test stand.

[@tjuan7]

Nice break-in bench set up.

[@makolemos]

Boa tarde amigos, tenho um motor os max 91 sx ,cabeçote com duas velas, qual combustível posso usar ?

[@Bob-d3s]

William did you get it to run correctly with that center glide bearing, os 105 was given to me with center glide I ended up installing a new 105 with regular ball bearings, and the 105 with the center glide I removed the center glide bearings in the oven at 400F and slamming it on a cutting board, I had alot of vibration with the center glide, your engine seems to run well on bench.

[@wjvail]

Most of my helicopter motors have a Center Glide Bearing and I have not noticed an unusual amount of vibration. That is at least 5, OS 1.05s, an OS .91, an OS .55 and an OS .37. I suppose anything is possible but, vibration induced by the CGB seems unlikely. Over the years, particularly when the CGB was first introduced, people reported some shortcomings but vibration wasn't one of them... Do you know how much time was on the engine given to you? Is it possible the CGB bushing was unusually warn? These bushings are know to run a very long time but circumstances could have caused it to wear prematurely.

[@Bob-d3s]

@wjvail well it took a dunk in brackish water so maybe the thermal shock had something to do with it

[@Bob-d3s]

@wjvail I'm not sure of the run time I think it was fairly new though, it was given to me around 2014 and that was about the time I stopped flying, and only recently I we t through the whole trex 700 nitro and replaced all the bearings and balanced everything, and with the new engine runs very well now, one more tank and I'll start leaning, have you seen tim jones tuning videos?

[@wjvail]

Thanks. I'm going to try and post more of these vid's as I make them and hopefully get better at production and learn something about video editing as I go. I have a friend who's son is in the steel fabrication business and he welded it up for me. There are some massive steel plates that go between the rails at the bottom for larger engines.

[@maxiescudero189]

hola que muffler tiene puesto?

[@metalwizard23]

I have an 91sx I did the same thing...poweebox muffler to put it on a airplane.... Runs good. But man it pukes out some oil. Does yours?

[@tommee10533]

Hello, I have the same engine. Could you tell me where you got the thumb knobs for the needle adjustments...Thanks

[@wjvail]

www.quickuk.eu/products/37/webshop_categories/nitro_power/engine_control/needle_valve_adjusters_h2502.html QuickUK makes them. I'm uncertain where your are writing from so I can't tell where your most convenient retailer might be. I've found them to be out of stock at most US shops so the last set I just ordered direct from QuiickUK. They are nice aren't they? Cheers, Bill

[@labperck]

Hello, wich propeller are you using?

[@김동명-i2j]

Is drive washer compatible with o.s 105hz?

[@wjvail]

김동명 Howdy Mate. Your question is not as simple as it would seem. If I remember correctly the prop drive washer in this video was from an OS .91 four stroke and it would work on an OS 105 if the OS 105 had a slot for a woodruff key. The .91HZ and the OS 105 do not come with a key slot and this prop drive washer requires one. The helicopter I was using this 91HZ engine in uses a woodruff key to key the fan to the engine so I had to mill a key slot in the crank. I had done this some time in the past so when it come time to make this video and put a prop drive washer on the engine, that little job was already done. Sorry. I know that doesn't help you much. Bill

[@schmittbros2]

What prop drive washer are you using?

[@wjvail]

Hey.... Thanks for looking. Err... Remembering back to March should be easier shouldn't it? I'm nearly certain it was from an OS .91FS Surpass II I own. The Surpass uses a woodruff key on the prop drive washer and the .91 HZ-R does not. There is no keyway in the HZ-R crank. The engine in this video has had a slot milled in the crank for a key for the cooling fan I am using on my helicopter..