So I bought a 91nx recently because there supposed to be amazingly light, according to Horizon Hobby they weigh in at 20 ounces with muffler.
This is a lie! This motor tips the scales at 26 ounces with muffler! Now I have heard horizon has a tendency to stretch the facts but I didn't think it was true.
Anybody else out there ever owned one of these motors? I know there runners, and the one I bought is in dam good condition and I only paid $90 for it, great compression, bearings look great and the piston has very little carbon on it.

They are supposed to be fairly good engines from what I've read here on RCU.

I watched a video of a guy flying a mojo 60 I think with the 91nx on the nose, it ran very nicely and hucked that plane around with plenty of authority

My Evo 46 turns 300 more RPMS than my other 46 engines on the same prop and fuel ( ST45-OS46SF ASP46 )
These engines are overlooked and cheep to aquire
I have an EVO 53 that has great power bought it new real cheep
They have true chrome linners
i am sure the 91 will be a good performer from my experience with other engines in the brand
Not sure how they would hold up for the long run as that is the true test of the great engines but with a true chrome linner they should hold up real well

Enjoy

I've learned the trick with evolution is to get rid of the needle adjustment limiter, the limiters are there to prevent less experienced pilots from messing up the needle adjustments, at the same time it limits those of us with the experience needed to fine tune a engine to run perfectly, once you get rid of those limiters these engines are gems that should last a very long time with that true chrome liner, I expect my 46nt and 91nx to outlast any of my OS engines that aren't ringed.

I've been around most of the Evolution 2 strokes and they all need hot plugs like the A3. OS 8 plugs are too cold.

Hmm that's good to know, sometimes my evo 46 is a little timid

.....

Do you dislike the cardboard box that OS send there engines in Tim ? Maybe the ink is too bright !

Pope don't get him going man, as entertaining as it is

.....

.....

You stand by your opinion and there is absolutely nothing wrong with that, I agree with you on a lot concerning OS, there is very little chance I'll buy a brand new OS ever again unless it's a ringed motor, I've torn down so many of there engines the last few months, so far I've seen peeling in 4 out of 10 engines.

as far as glow plugs are concerned, I've never experimented much with different brands, I'm quite ignorant when it comes to them.

.....

Thats the second time in 3 posts that u said u wont post anymore . With kiddies on the way your gonna need more self control !!

No panties in a bunch here . I dont wear any . Get that picture out of your head !

The only OS that I ever liked was the 50SX. It ran well and was ringed. I had a good friend who bought a couple of them.

not another one ! its like a tag team wrestling match

Guys all battles aside I have 2 Evo 91's and love them both. One is in an original GP patriot 40 size swinging 11x11- flies fantastic and because the Patriot design is so good it handles it no problem. Next is a VMAR mig 21-started by chicken stick first flip 14x8. Flawless out of the box. The weight issue may be secondary to the muffler which could easily add 6 ounces but honestly I have some 60's in the low 20 ounce range as well. The sad thing of course is the company no longer makes these and they are not exactly floating around eBay.

Semi or unrelated to the topic: I had an EVO 100 that was really hard to get reliable until it had many flight on it but that motor is very heavy. Personally I have had no issues with OS engines. I have an old os 91FSR which still hauls the mail. I have not done rpm comparisons however. The only motors I don't have generally good experiences are FOX which no one uses anyway. Some ran well some did not unless you went through some sort of machinations that were available- spray bar filings and shims and such. If you have the money to spend and need performance,simplicity and reliability nothing beats a Jett in my opinion. I have 3 of his 90 size- all scream, all easy to set and all long lived.

I just bought a 52 nx and want to get rid of the limiters how hard is it to remove the idle limiter... thanks Ken

IIRC, they are held on by a set screw.

Thanks Ken

Removing them helps the engine a lot.

whats the best plug to use on the 52nx ????