shims on os105hr-r

[Erutsyn]

HI. I had an os105hz-r (got it last year). I am using 30% wild cat Curtis.  I added a second .02mm shim. In the beginig I had to increase fuel flow by turning the  fuel scrue . After a wile it started. Then I was running it and even flying it with 2 1/4 main and 1 1/4 mid. It would fly well but on sum flyts it woud stall and I had to autorotate. I called hobyco and explained . they sad to send it. They abviously do not know a lot about the engine. I end up bying a new one from them (they coudnt warranty it). I still do not now what was wrong with it. When I get my new one  : how many shims should I put ? And if you have any thouts about my first engine.

[Kevin Dalrymple]

I run 20% nitro in my 105HZR. 30 seems to high. 15 to 20 percent seems to make plenary of power for this motor and the fuel is cheaper with lower nitro percentage.

[Chris Wall]

I am running Rotor Rage 22.5% and runs great with stock sims.  I agree with you in the Hobbico support, hard to get a good answer out of them...

[Erutsyn]

I have to run 30% fuel. I have about 35 cases still of Curtice.

[Jeff_Barrett]

You need both shims in that motor for 30% as directed by the manual.

I found the motor ran WAY better on 22.5% with the stock shim only in it though. Ran too hot on 30% IMHO.

I too have a lot of 30% so I just went and got some 15% to mix with it at 1:1: ratio.

[Erutsyn]

It's a good idea. But if you run 30 , do I need to have all 3 shims or just   2   .02 ones? I do not mind a hot engine as long it does not stall

[Jeff_Barrett]

You use 2x 0.2mm according to the manual. This is what I ran when on 30% ....

I found my motor runs smoother on 22.5% and actually made more power it felt like.

[Erutsyn]

I received the replacement os 105hz-r. I put 2 additional shims .02 and .01. In total .5.  I am using 30%. The engine stated from the first try. It runs perfect. I will start leaning it after a wile.