I just bought an OS 56 alpha. Was using Cool Power 15% heli mix to break-in the engine. Noticed at full throttle, the temp at glow plug hit 276F. Is that too high? I tuned it to max power, then richen a bit. Should I be using 4stroke fuel instead? I also noticed at idle, there are alot of vibrations. Am I using the wrong fuel? Thanks for your replies.

You'll find differences of oppinions here but the way I see it, there are more moving parts in 4 strokes so I think the extra lube is needed especially if the engine is mounted upright and lube needs to travel up to the head. I also tend to run my Saito on the rich side. If it doesn't smoke a little in the air, it's too lean. I don't notice much vibration on mine since I got in the habit of balancing my props.

This is from Tower Hobbies on the OS .91 4-stroke page:

" NOTE: Certain four-cycle fuels cannot be used due to low oil content."

Some 4-strokes like a little more nitro but they all need good lubrication. Just choose a fuel that meets the recommendation in the owners manual and you will be fine. It does not have to say "4-stroke" on the label.

I add 1 oz/gallon of extra castor oil to my "regular" S&W 10% Nitro and use it in my OS 70II Surpass engines (and all my other glow engines, also).

I fly the same fuel on all of my planes, 2 stroke and 4 stroke, which is Cool Power 15%. You'll do fine using the same fuel on both.

Ken

Check out the manual or instruction sheet that comes with the engine. It will generally contain the fuel requirements for the engine. The fuel I use (S&W 12.5 % nitro and 20% lubricant) satisfies the requirements for both my 4 stroke and 2 stroke engines. Like RCKen, I use the same fuel for both.

DaveB

The cool power "4 stroke" and the regular fuel are the same thing. If you want it to purr like a kitten run 30 percent heli fuel but its getting awfully pricey.

When you say add castor oil, do you mean the same castor found at the local drug store? That is the only place that I find castor.

Thanks for all your replies. My manual says 5 to 20% nitro and minimum 18% lube. Cool Power 15% has only 17% lube. So am I in trouble?

Also my 13x6 prop is brand new, so I doubt it's unbalanced. And my engine is mounted sideways.

Cool Power MV has lubricant of 18%

You need to ignore all of the 'descriptive' terms on the fuel bottles and web sites. Most of that is intended to make you think one brand is vastly superior to another, or that it is something special for a certain type of engine. In general, that is just marketing hype.

You need to know the nitro percentage and the total oil percentage. It is also good to know if the oil is synthetic, castor, or a blend of both.

Compare this info to the fuel requirements listed in your engine's manual, and it's easy to tell if the fuel is ok no matter what the other words on the label might say.

For the OS 56 Alpha, Tower product notes says "Fuel: 5-20% nitro with 18% lubricant content." The manual probably has similar info.

Klotz Benol racing castor can often be found at motorcycle and go kart shops. If you do not have a local source, Omni and Tower sell it for $7.39 per pint.
http://www3.omnimodels.com/cgi-bin/w...I=KSFP1175&P=0
You can also buy castor from www.sigmfg.com
There has been plenty of arguing about using drug store castor. As long as it's pure, no sugar or other additives, it seems like it should be ok.

Thanks for the explanation.

Im not using Cool Power MV. This is what Im using:

http://www3.towerhobbies.com/cgi-bin...?&I=LXGHB4&P=0

17% lube ultra high viscosity. Does it matter if its ultra high viscosity or multi viscosity?

OS recomends 18% lube and 5-15% nitro for all there engines 2 and 4stroke the 1% is negledgable a little extra oil is not too bad for a 4st up to 20% is fine,heli fuel, 4st fuel,airplane fuel, there all basicly the same.
as long as there within the specs of the engine your running there fine for use fuel is labeled for marketing.
the basic components are the same, alcohol, nitro, and lube.
it wouldn't hurt to add a couple of oz. of oil to the fuel at 17% theres about 22 oz of oil in a gal of the Omega a couple more wouldnt hurt.

the engine your breaking in was set up for 15% nitro and 20% lube its the base levels for OS engines running less oil you should run it a little rich is all for the break in runs.

Ken, that's what I have been using for years in all of my 4-strokes (Most of which are OS)

It will be fine

The drugstore castor is at least, and probably more pure that the other types. I ask the drugest about this when I was looking for a small abount of additive oil. His comment was the to get the FDA approval, it had to be very pure. No additives. Big bucks though. I think a 4 0z bottle cost me $7.00. Last year, I bought out a guys collection and there is a jug of Sig Castor that is 3/4 full. Don't know what I'll use it for.

Don

I do what Ken does, I fly everything from 1/2 A to A 1.40 YS on Power Master 15% with 18% blended oil.