Alright time to ask...OS 91SZ-H PS-Hyper

[Greg Alderman]

OK you engine experts...I have tried every thing you all have told me to try and I am at my wits end with this motor...

Running Hattori SB-18, Magnum 30%, and .020" in shims (although I have tried everything between .008 and .024) and the motor is running so rough that I can't keep my backup Magnum in the air as it is breaking parts due to vibration and violent tail jerks...

I have roughly 15 tanks through it now and it is not getting any better...

Run-out on fan is less that .002"...(before anyone asks) so I would think that would alleviate a mis-aligned fan or bent crank...

This is my first OS and I am ready to put a YS 91 back in and write this off as a lesson learned and stay with the motors I know...

HELP!

[Rodney]

You go ahead and safe yourself some greif. YS all the way for us that want to fly, fly, fly.

[Clintstone]

Greg I told you what I thought.....................but I refuse to say I told you so :noteworthy

[DebianDog]

But Rodney... Greg got a REALLY good deal on it! He was like a proud father talking about his new motor a few months back. :lol:

Sorry Greg, just too funny.

[Ivan]

Did you check the bearings? OS seems to like to shell bearings.

Other than that, I would have to agree that YS is the way to go. I wish I had waited for a YS instead of taking my CSpec as a consolation. :arggg:

[Greg Alderman]

You are such an Ass Dog! :D Go ahead and say "I told you so" no biggy...should have stayed with my YS's!

alright...walking out the door to drive to XFC...later all...

[cdrking]

Greg,

I'm considering a OS but have run the YS for a while now and really like it. With all the problems I see people having with the OS I may wait until they/you get it all worked out. :)

Questions everyone seems to be having with this new motor:

OS:
What shimming?
To vent the tank or run muffler pressure?
Dual plug Viper head?
What fuel works best with a particular shim?
Header tank or not?
Do I have to have an OMI carb mod?

YS:
Put fuel in and fly!

But it's the quest for more and more power.

It seems to me that it's not a plug and play engine at all. I for one don't have the time to mess around with all that.

Jeff

[JohnSSN700]

Wow, I haven't seen that many people having problems with this engine besides figuring out how to set the needles. Mine runs like a top, starts on the first try EVERY single time. I'm no pro but I love mine. I have been running 15% CP but will switch to 30% this weekend. For the 30% I just added the second #2 shim, hope this does it. I have the Hatori SB-17.
Where are you needles set? Mine are/were as follows:
High- 21 clicks out
Med- 6 clicks out
Low- just a hair past 1 o'clock

Even with the mid just six clicks out mine was still running a tad rich but making alot of power, and this was on 15%. :dontknow

[JohnSSN700]

Wait, whoaaa, I just read your profile! You still on boats? Your not working/attending National Defense University/ICAF are you? Any relations to Lance Alderman?? Any of these names ring a bell??

Edit: names removed...........

[SteveL]

I have heard of Charlie Brown :idea:

[JohnSSN700]

Oh nooo Steve, you didn't look at those names did ya?? :arggg: