Those numbers are tuned for max rpms. I'm getting 26 pounds of thrust though. So how can that be? Bob at dlusa said that my motor is running a little low but the thrust is right so he said fly it and see what happens when I go to synthetic.

No, your engine is not crap. The Xoar is a high load, high thrust prop, mine would only turn a JXF 22x8 6900 the first time I tached it. I thought the same thing, but it pulled 23 pounds of thrust for a 14 pound plane and I thought. "that should be alright" and it was! and it just keeps getting better. I do a poor job keeping track of my fuel as I mix a half gallon at a time and have not kept track. I would guess I'm aroung the 4-5 gallon mark and I switched to amsoil sabre at 80:1. The PT carbon turned 7100+ the same day it turned the JXF 6900. The next time I tached the PT 7300+, the time before last, 7560 I'm like holy crap batman, and now 7900, it really was screaming. I'm going to recheck it. I don't think the baro will be as high but I will check by this weekend at the latest. When I see a number that high I let off immediatley, just seems like too much for a 50cc.

If it fails and I have to buy a new one, I will. I love this engine and I would replace it immediatly (or whenever the next shipment came in)
I don't expect it to be a problem, more likely to hurt it in an accident than for it to hurt itself.

Scott

I think I'll try the 22x10 maybe I'll like it.

Disclaimer, thrust measurement taken with unused 50 pound spring fish scale. Accuracy unknown.

Buddy, if you're getting 26 pounds of thrust I wouldn't care what the rpms are! If you want to 3D then thrust is the number you want to look at. The more you have the better it is and if you can get to a 2:1 thrust to weight ratio you are awesome!!! Doesn't matter if you're turning 5000rpm as long as that thrust number is up there and it spools up fast!! BTW Don't load the engine too much trying to get there. Bad thing!! I'd say you're just about right with that Xoar at those rpms.

My mate got 7900 on a Chip Hyde 22x8 and Chip Hyde quiet pipe and that was checked with 2 different tachs. This was a new engine and boy did it rip in the air! He has now changed to a Menz 23x8 and getting 7200, sounds a little quieter on the air but still great vertical etc.

Let's address a couple of things here.

Props: I've been testing many props over the years and one thing I noticed is there is no such thing as the perfect prop for any two setups. What I mean is you can have 2 of the exact same setups in two different areas which might be close to the same altitude, etc. but get two different results. I've tested Mezjlik, Vess, Xoar, Bambula, NX, Belia, ZM, 3W, PT models, TBM and a host of others. The only good way to test is to try others. I've seen planes not like one prop brand and love another. My Ultimate is a good example. It hates the PT models, the Xoar and the Belia, but absolutely loved the Vess. All props were 22X8 and in the Vess case, the 22A. All others would barely hover the thing but I'd get great vertical. The Vess hovered it with ease but I lost a bit of vertical and the plane was definitely louder on ALL of the wood props with the Xoar being the worse. Downline braking on all the wood props, but the Bambula, left me worrying about the speed the plane was gaining on the way down where the CF props had great braking effect and were way more manageable, speed wise.

RPM: Max rpm is NOT what you need, thrust is everything. You can certainly have an engine turning 6500 but putting out more thrust than one turning 7500. Thrust is everything and the best way to get that is to prop the engine so that it is at the top of it's torque band, not rpm range. Most engines stop making torque at about 80% the max rpm. You can actually see this and hear this if you are paying attention.

Just be careful about too much load until the engine is completely broken in

I agree completely. Some folks get caught up in the whole "mine turns 10,000 rpm with a 37x16 prop" blah blah blah.

Thrust is where it's at.

I'm just posting my numbers to show how they can increase as the engine breaks in. I thought because my JXF would only turn 6900 that my engine was not as good as others. But now I'm the one with the RPM's to die for

I could not get 7900 today but I think it's close enough to verify it DID turn 7900 last night, no bull.

The one pic is of the tach under the lights here at work to verify it's reading right.

Once I make sure the 22x10 JXF is balance I will try it on there.

Man, that is a lot of RPM's...[X(] I think I'd want to slow that puppy down. I know clearnace will be an issue on that plane but I think a 23x8 would be better. The 22x10 is gonna give you more landing speed than a 23x8 would unles of course you can idle really low

Stick bender that is unreal! I hope my motor pulls that hard after a couple of gallons.

Tonight I got my yak out to see about this taching thing. 50 degrees out it ran 6900rpm but on the pull scale it was 25 pounds. So it must be my xoar prop, it loads it down alot. O, also my j-tec muffler was loose. Good thing I got out my plane. That would've made me real mad at the field. How do you guys keep that pipe tight? I tried blue lock tight last time.


And to all about the temp of the motor running at 2500rpm for about 15min. It wouldn't go above 139 degrees.

paul, bill stated that he used the red (high heat) gasket permetex on the bolts. I agree with him that I never had a problem.

Paul,
My engine is the first type, thin mounting lugs on case. The engine mounts were version 2 and the ignition is version 2. Serial number 166

It sounds like your engine is running fine, if you want to impress yourself with static rpm get a 22x8 zinger pro. I bet you could spin one of them 7400+ but they are not even close to the prop a Xoar is. I have a zinger pro 22x8 I bought as a backup but I have not broken either of my good 22x8's so the Zinger has never even been drilled to fit.

And for everyone, lets not forget that no 2 props are the same. You can get 2 props, same mfg., same size... and be 300 rpm different static. Don't get caught up in static rpm, fly the prop that works for your combo and the way you fly.

But good props will give you the best chance at happiness.

Beila, Xoar, Skorepa, Menz, Mejzlic, NX, JXF, 3W, Evolution, BME these are the ones I can think of. You could get a prop that doesn't work for your application, but you wont get very many "bad props" if you stick with these. Remind me if I missed some.

Scott

Paul, I actually use JB weld on the threads of my muffler bolts to hold them in. If you heat it up a bit with a small butane torch it will release so you can get them out but red Locktite will probably work just as good.

Scott Do yourself a favor and use that Zinger Pro to stir the next can of paint you open. There's a reason they spin so high and it's not a good one. That Xoar is stiff and gives good thrust. If you really want to change it out for more thrust Paul put a Vess 22 or 23B on there and don't sweat the rpms. Get yourself a Berkley digital fish scale and start measuring your thrust. Check the rpms against the 80% rule Bubbagates told you about and see if you aren't getting really high thrust with the right rpm numbers to make your engine last.

I check my rpms at 80% of 9000 should be 7200 I'm just a couple of tanks of fuel away from that. Thanks for the input guys.

Lou I put my pipe back on tonight and I used red locktite. I will try the JB weld next time if it comes loose again. Does the JB weld come apart if you want it to? Have you ever tried red locktite?

If you heat the JB Weld with a small pencil butane torch it will come free. Red Locktite works well also. Just don't use lock washers on the stock muffler. If you do it won't seal around the bolt heads. I like Bubbagates idea with the Permatex. May try that next time.

Do any of you guys run JXF props I broke my xoar today and have to get a new prop. Also my J-tec muffler is going to be returned because I can't keep it tight. I went back to the stock muffler so I'm gonna order a new cowl, and the place I ordered my plane from has JXF props. So new prop and cowl together will save some shipping costs. But I want to know if the JXF ok.

Hey Paul, how many flights you got on that bird yet?

I got a tip from Ralph at RC Ignitions to use Permatex Ultra Copper. It is about 8 or so bucks a tube but will last for many engines.
Throw the exhaust gasket away, put a bead on the muffler flange and on the bolts and don't fly it for how ever many hours it says on the tube. I just took the exhaust apart on my (other brand) engine after 37 hours of flight and nothing came loose until I put the wrench on it.

Richard

Yea that stuff works great--they make it in gray too--looks better than copper

reply to all, have a patty w great planes arf, wont what i cant afford a da 50 700.00 $,but will the dl work and mount, the plane had a da 50 got the air frame and some servos will be fun if the engine will perform , have read a lot but seems like the muffler is the only problem[&:] thanks frank

If a DA 50 came out a DL-50 will go right in.

My understanding is JXF is the OEM manufacturer of many of the popular prop brands on the market now, as well as ultralight props. They work well for me and should work for you too.

What size are you buying? I have a 22x8 but I want to try a 23x8 also.

Terry I have to have a 22x8. I broke my xoar on a stick. I'm still breaking in.

I put my JXF 22x8 back on to slow the engine a little (or so I thought) The JXF (and Xoar) are really high load props. I have not tached it but the static rpm is WAY down. The sound at wot on the ground is dramatically different. I have not tached it but I lost a lot of rpm. So if your looking for high static tach numbers don't get a JXF or a Xoar. But the prop is awesome. It seems to have a higher effective pitch than the PT Planes 22x8n. The plane doesn't slow to a crawl for landings with the JXF but it's slow enough, just different than the PT.

Contrary to what I would think, the JXF actually punches out of a hover better than the PT did. This makes no sense to me as the PT obviously spools up faster. I guess the JXF just produces so much more thrust at low rpm, the thrust is right there when you hit it, no need to spool up. So you have to fly a prop and see how it works. Static rpm just tells you if your prop is too little load, or too much load. But too much load for my combo would be under 6600 static. a 20 pound plane would want something in the low to mid 7's

Here is a video of mine with the PT (and no wheel pants at the time, they are on now)

It's not the worst RC video I've seen, but it's not the best either.

http://rcuvideos.com/item/CVS3MDX5X4QLBWYG

http://video.google.com/videoplay?do...54916657265025

Most of the flying is idle to 2/5 throttle(minus 20% expo), I stab it once on takoff about 3/4 and back off in the turn, and I go wot on one upline where I go in slow, wait till it stops climbing, then hammer it.

Scott Gaines

I realy liked my xoar the pull was way down low. It uses the torque of the dl-50 to pull the plane. Its awesome. I found an RCU forum about xoar. It said that JXF and xoar are sister companies. So I'm gonna order a JXF prop and a cowl from the place I ordered my plane from. Hopefully J-tec will take that pice of crap muffler back.

Here's a prop comparison posted on one of the other threads by Pat Roy. Note that the Vess is the only 23" prop.

A quick prop comparison.

Vess 23A: Lot's of pull but lot's of load. Lower rpm.
MSC 22-8: A 150-200 more rpm than the Vess. Lot's of pull with less load on the engine.
Bunny/BME/Xoar/NX 22-8: High rpm but less pull.
Menz "S" 22-8: Around 7,500 rpm but good pull with a Taurus 52.
TBM 22-8: Spittin' image of the Menz, but thicker through the blade. Haven't run it yet but should land between the Menz and MSC.