I got an OS 10 LA in my House of Balsa SpaceWalker. I can get the engine to about 10,000 RPM on an 8x4 or 7x6 prop. Is this a good RPM for this engine, the RCFAQ rpm index doesn't have any data on the 10 LA. Well anyways it's running erratically. When I have it set real rich it runs slow but runs, if I try to lean it out it dies at the top end. When I do get it to a decent top end speed, it has a really slow transition from idle to full RPM. Is there any trick to these little engines. I'm runing 15% Omega fuel, and it has had about 10, 3oz tanks run through it. Does it take a long time to break in?
Help running an OS 10 LA
Aug 01, 2003
12 Replies
I run 7x4 props on my .15's, so to me it sounds as though it is over propped. But what do I know?
Ed Cregger
It started to rain today, so I ran out of time. But I will give a 7x4 a try. I found on Tower Hobbies website that the 10LA rpm range is from
2500-18000. So it sounds like I should be getting a lot more rpm. Is the A3 plug OK for 15% nitro?That same web page suggests a 7x4 or 7x5. Ed hit the nail on the head. I guess the engine comes with an A3 plug. If I recall correctly, that is a long reach plug. Personally, I would use an OS 8 plug. JR
I'm at a loss on the glow plug, Norm. I could never afford OS plugs back when I was messing with the smaller engines. The smaller engines are lots of fun.
Ed Cregger
The engine won't develop much power at 10,000 RPM. Try a smaller prop...one that turns at least 14,000 RPM on the ground. You will be surprised by the difference in power you get (plus it will be easier to adjust).
Ed Cregger
will give a 7x4 a
range is from
more rpm. Is the
though it is over
can get the
good RPM for this
LA. Well anyways
runs slow but
do get it to a
idle to full RPM.
15% Omega fuel, andtake a long time to
Get a short plug too, just in case. Those smaller engines don't have much head space and a long plug may be "too" long.
Don
Well I tried an OS 8 and a 7x5 prop, the fastest rpm I could get it to was
12000 rpm. Changing between an A3 and OS8 didn't change the rpm. I also don't get any additional rpm if I leave the glow driver on it. There is no airbleed screw on the 10LA, so the only adjustment I have is the needle valve.
3.95oz for the 10la and according to the specs it will turn almost the same prop as the Thunder Tiger 15. But obviously not my 10la.
Most of the .15 size engines I have encountered use short glow plugs, but there were a couple that used a long glow plug. I guess you have to check the engine out to be sure.
I ordered a card of K&B 1L glowplugs from National Hobby Supply when they were still selling airplane equipment. I failed to check the card when it arrived. Some time later I went to get a plug from the card and it turned out that they had screwed up the order. They sent me a card of K&B idle bar equipped long glow plugs. Argh! The point being, if anyone needs any long K&B plugs with idle bars, keep me in mind.
Ed Cregger
Don't believe specs. The TT is a pretty good engine, and has 50% more displacement. For the .10, a 7x3 or 7x4 would seem plenty prop to me. More than that, and you bog down the engine way too much.
The fox long reach with idle bar does not fit in the 10LA.
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