K&B Stallion 35 R/C #9042

I have one of these engines in perfect condition. I would like to convert it back to control line use. If I remember correctly, it was not usable for r/c because it would not run in 2 cycle. Even after a gallon of fuel it would get hot and stop if it was leaned out. I think it would look really cool on a Viking. Is it too heavy for this plane? Does anyone know what venturi, NVA, fuel, prop, muffler,
etc?

Thanks for any help!

It will run in a two, certainly. In fact, its run characteristics are somewhat like its forebearer, the Greenhead series. But it is more like a Wet Two. I would put the Stallion somewhere on a continuum between a Greenhead/OS Max Steel Fin on the one end, and a Fox/McCoy (Redhead) on the other, run characteristics-wise.

Who stated that this motor would not run in a two cycle, even a leanish one? News to me. Is this one of those "typical" RC-flyer statements regarding a non-broken in engine?

I have one on a Smoothie, and Wet Two it is. Don't have the motor in front of me to provide venturi specs, but a standard 10-6 seems to work well.

Re-reading your post JR, I didn't realise that it is your own Stallion that you are referring to, so no offense intended. Still, your motor is not typical, if it is still "hot" even after all that breakin. Perhaps, a bit more breakin...

Thanks man- none taken! I put this engine away in 1975, so I'm a little fuzzy on the details. I have no way of knowing what kind of fuel I was using. Am I correct in assuming that this engine needs all castor? I grenaded the rod on my Fox 35S by not paying attention to this detail, don't want to make the same mistake again. I can't get all castor fuel at my LHS. I hate to pay $100.00+ to get a case of fuel shipped but I may have to if I want to run these older engines.

Thanks!

>I can't get all castor fuel at
>my LHS. I hate to pay $100.00+ to get a case of fuel shipped
>but I may have to if I want to run these older engines.

You may not have to pay $100.00 for what you need. You should be able to buy a separate bottle of Castor oil from you LHS. If they don’t stock it they should be able to order it for you in small quantities. Then you can do like I do. Buy the pink R/C fuel and add castor accordingly. Go with a bit higher Nitro content to compensate for the added castor Adding additional Castor will lower the Nitro percentage a few points. In the end you will have the Castor fuel that you want.

I use a 25% mix of castor and synthetic, majority castor, in these older non-ABC engines. They seem to hold up well with this fuel. They don't gum up nearly as quickly, either. Currell

Adding oil to the fuel won't actually change the nitro content. The "fuel" is just the methanol/nitro and as far as the needle valve is concerned the oil is just along for the ride. Adding any amount of oil leaves the methanol/nitro ratio just the same but the needle may have to be opened a little more to get back the same flow rate of "fuel".

I was confused about the oil issue with these older engines. I was afraid they wouldn't tolerate ANY synthetic. I have a supply of castor from Sig, so I'll give it a try.

Thanks guys!

I've got one of the R/C versions, and two of the CL versions. They definitely don't like low oil content or synthetic. The R/C seems to run hotter than the CL version, maybe because of the restriction with the throttle.
Seems to me, (I'm at work, don't have them with me) that K&B cut the intake venturi down to provide mounting for the R/C carb, so you would probably have to make your own venturi to suit.
I used to fly one of the CL versions in a SAM OT R/C plane using a shut-off for timed runs. With the plastic insert removed,and a Dubro Muffleaire II, I could tach an 11-5 Wood prop at 12600. This engine is currently in a Goldberg Shoestring. Starting to loose compression, though.