I am getting ready to build my Primo. Was thinking of the OS .55 until I saw these. There was a revue on them in the glow engines forum. Seems positive, plus you can buy two JBA's and have change left for the price of the OS. Has anyone used one on a 3D plane yet?

I called Kange models and asked them about the JBA. They said it was ported more for small props/high rpm running and wouldn't make that great of a 3D engine. they recommened the SK50 for 3D since it was tuned more for lower rpm/larger props. Not sure how they run but the price is right.


Mike

I started the thread on the JBA .56. I also have 2 OS .55AXs and an SK 50.

The JBA does not respond to a Jett tuned muffler like the OS, so I do not think it is set for high rpm that much.

I have it on a Goldberg Wild Stik, but only have 1 flight. I have been under the weather with the bug that's going around. Before the JBA, I had the SK 50. I flew both on an APC 12.25x3.75 3D prop. The JBA gives more vertical. I did fly mostly at half throttle due to the large controls on the Wild Stik and got no loading up. Seems to be a good carb.

The OS is the sweetest running engine, but, as you said, it's pricey. If I was going to pick between getting another JBA or SK, I'd get the JBA 56.

Ed,

It was your post that got me thinking about the JBA .56. I have not owned a OS engine since the mid 80's, and thought I might try one again. I have heard many good comments about the OS .55AX, however, if the JBA runs as good for less than half the cost, I might just have to try one.

Tony

RT:

Try the thunder tiger 46. Its built better than the OS, true ABC construction and 6 bolts on the head. Have one on a mojo, 12 X 4, flys and hovers well. Price is right. You will probably have to change out the bearings after the first year just as you do with the OS and St's., but the TT chrome sleave gives it a longer service life. ENJOY

rmenke,

I have a Thunder Tiger .46 on a Hot Knife profile. Plane is beat to &$!# but the engine just gets better. The engine and plane are now two years old. I run a 12 X 4 wood prop because it spools up much faster than the APC. Original bearings!

I am looking for more punch, so to speak, than the TT for the Primo. I have a Saito .82 I could pull off my Funtana X50, but I kind of want to keep that flying.

I had a bad OS about 20years ago and have not run one since, but the reviews for the AX .55 are good. I have two TT .40 for pylon and two TT .46. One in the Hot Knife and one in a pattern practice plane. Great engines.

Just thought I might try something different. They are inexpensive and Ed's review sounds good.

???????

Tony

I'd steer clear of cheap Chinese motors -- in my experience the quality varies wildly from one sample to another so it's sometimes a bit of a lottery.

I've got an ASP52 in my Katana profile right now and it's got gobs of power but it's not fun to fly. Most of the time it's fine but every now and then when you come in and pop it into a hover at knee-height the engine will stumble and you'll end up busting the rudder (again).

This is an old airframe so i don't care -- but there's *no* way I'd risk a new bird (especially something like a Primo that you've got to build from a kit) to anything other than a Saito, TT46Pro or OS.

How much did your Primo kit cost? If your cheap Chinese motor dies at the wrong moment you could end up wasting that money by totalling your plane -- leaving you with nothing but a broken bird and a crappy motor. Even if the motor doesn't kill the plane, an inconsistent running motor takes all the fun out of trying to fly 3D because you end up having to fly defensively, always worried that a stumble or hesitation could result in a crash.

I learned a long, long time ago that cheap Chinese engines are a false economy. Unfortunately I lose a plane or two every now and then when I wonder if things have changed and take a chance on another.

The last bird I lost to a Cheap Chinese engine was my lovely Primus 50 clone that was lost to a crappy SK50 -- failure to transition properly. That same plane had flown for four years (first on a TT46Pro and then on a Saito 82) without a scratch -- but within three weeks of fitting the SK it was broken clean in half. I should have known this engine was a lemon when it came without any usable threads in the glowplug hole -- I had to tap them myself because the tooling they used was obviously so worn that the tap barely scratched the sides of the hole. I gather that SK and JBA are made in the same factories and share many castings/tooling setups.

Funny enough, the SK90 I also bought at the same time is *perfect* -- but I've heard from a few other SK90 owners that theirs are nothing but trouble. As I said -- the quality of these cheap Chinese engines just varies too much from one unit to another.

Not worth the risk (IMHO).

Should you buy a JBA you *might* get a good one, Ed obviously got a good one -- but there are very high odds that you might also get a dog -- which means you'll have wasted that money and still have no suitable engine for your Primo.

Remember that there's usually a *huge* difference between price and value :-)

Why not contact Paul @ Swaneyshouse.com and get a Webra 50, Cheaper then OS and very reliable more power then the TT

Paul Swaney now has the Webra .55. Thought about that too. I would hate to lose the Primo because I went cheap on the engine. It is a beautiful airplane and I should power it with something that is knowm to be rock solid reliable.

Actually also the TT is nickel plated, and not ABC (chrome). TT have however had 100% success with this, so has Webra. I think OS is the only brand using nickel with mixed success. Every time a peeled sleeve emerges it is a OS engine

IMHO a 55 is too much,, the Primo should be a rocket with a 50, And unless your into drag racing no more would be needed for 3d,
I just started a Primo a few min ago and I am thinking about a Saito 62.

This will be my 3rd and I have 2 82's (1 nib), but I'm pretty sure it will come out sub 4lbs with a 62 have pleanty of 3d power.


If you check Pauls prices they are very Low compared to OS and I've only heard good things about the little Webras

I bought my first Webra back in about 1970, they're great engines.

The only thing to watch is that you don't run too much nitro -- Webras come from a land where lots of people don't even use nitro so 5% is *plenty* and more than 10% will probably cause problems unless you add extra head shims (who's got those?)

Paul told me a couple of months ago that he was ordering them. 1 recent report form a Bro was that heli 30 was working in his Webra stock no shim[X(] Its got me wondering if it wasn't just rumor, did you try it Xjet ?