Rimfire123

Can anyone identify this engine. Has an odd shaped jug. It is for sale with plane on not so local craigslist. Looks 80's or 90 'era.
Thanks
Jack

Tailspin

That's an Evolution engine. Horizon used to sell them. They may still have parts.
Steve

GREG DOE

Can't tell for certain, but it could be a .40 or .46. A lot of them were put on ARF trainers, and they had a preset carburetor, where you could only make small adjustments to both the high, and low speed needle valves. The two odd looking blue "wheel collar" parts on that engine on the needle valves are the adjustment "limiters". Probably more of a bad idea, then a good idea! They were trying to provide a product that newbie couldn't mess up too bad. The engines themselves on average are fair. There was a batch that had bad carburetors. Evolution addressed the problem, but I don't know if there is any way to differentiate between the carbs. The .46 is one of the approved engines for AMA event Sport Quickie 500 Pylon (event 424), so I have three of them. Mine are definitely of average performance, but I've seen some that ran great. Most of us in the racing community have found that under the rigors of racing, they don't last very long. If it hasn't been abused, and the price is right, it could possibly give a good service. looking at the external corrosion, there is the distinct possibility that there could be internal rust, and the bearings may need to be replaced?

Rimfire123

Thank you fellows. I was not familiar with that one.

GREG DOE

The engine in the picture is an "NT", the earlier version. It is distinguishable by the outlet on the muffler, which is angled. The later version was the "NX" which has the muffler outlet coming straight out the rear of the muffler. This doesn't necessarily guarantee that it has "problem" carburetor. As I recall the bad carbs had air leaks, which made them difficult to tune. If you got it to run well wide open, it wouldn't idle. If you got it to idle, it would die wide open! I can't say for certain, but I believe all the parts for these engines are gone, but you can always check to be sure.

Rimfire123

I think I will pass on this one. And I had a K&B 40 that was sort of like that. Hard to tune to both idle and flying speed. So I just tuned it for flying. It never let me down though. Never had to deadstick it.

1200SportsterRider

That one appears to have the limiter on the HS needle that prevented a noob from running them too lean. Sometimes the limiter was too limiting and prevented peaking it.
A 46 with the limiter.

GREG DOE

Sportster Rider, The picture you posted is the NT. The NX (later version) has a blue anodized head.