I have one of these and can't seem to get the power or rpm out of it I hear others are getting. The engine is new and has about a 1/4 of a gallon thru it, I had a 22x10 on it as the manual says that is the prop for break in and could only get 5800 rpm. I then put a Vess 23A on it and now can get 6100-6200 rpm out of it but I hear others are getting 6500-7K even when new? I have played with the adjustments and they seem correct, I also was using 25:1 oil as thats what the manual calls for but now have moved to around 35:1.
Other than not enough power/rpm it seems to run OK.
Any suggestions?

25% oil? eh....you sure about that? The numbers posted that I have seen, around 7000, are with a 22x8 prop.

25:1 is what the manual says.

I figured that's what you meant....just playin 25:1 is quite a bit different than 25%

I'm sure he means 25 to 1.

If your engine is new then you got the new muffler which is a drag on power. 3mm changed the muffler design a few months ago and put on a smaller outlet pipe which drags power down at least 400 rpm.

Since then I only sell the engine to people who plan to use a canister or who understand and accept the reduced power with the stock muffler. I'll resume promoting them when 3MM goes back to the original design.

You want a muffler with minimum 7/8" OD outlet.

TF

I also forgot to add that I am not using the stock muffler. I am using the K+S canister.

I believe the manual gives a range in ratios, not percentages. At 25 to 30% you are running a lot of oil!! Try a new mix of 32-1. That's 4 ounces of oil to 1 gallon of gas. I'm certain that if you are using a 25-30% ratio it's a very large part of your problem.

Next is carb tuning. It has to be done every time you change oil ratios and prop sizes. I think you might like a 22-8 a little better. My personal preferences do not include Xoar or Vess. For a good baseline prop try Menz or NX.

Using a 32-1 ratio your engine will take a few gallons (about 5 hours of running time) of fuel before it has fully broken in.

Im not using 25%, it was a typo, please reread above

My manual specifically says 25:1 oil mix.

25-1 is still too much oil but it would not account for that much loss of power.

Where did you get the header you are using? What type is it?

Have you tested the engine with the muffler that came with it?

I've seen a couple engines that had not-so-good piston rings in them. They perked right up when the rings were replaced, but it's impossible to tell if that is the problem from here.

TF

I bought the header from you. I have not tried the stock muffler. I was told to send in the engine to have them check it out (Cermark) but would like to avoid that if possible, if not I will have to do it.

I'd try 32:1, fresh gas, a good 22x8 prop, (my favorite lately is NX)...check and/or clean/replace your plug as needed, tune the engine properly...and report back. If the exhaust is a question here, run it again with what you had on it, run it with the muffler that came with it originally, and run it with no muffler at all....again, report back. Could just be a combo of oil ratio, mixture settings, prop choice, and exhaust. All things that can considerably contribute.

I have done all of the above already, cept instead of using a 22x8 I used a 23a. The engine is new, plug is new only has about 6 flights on it so not broken in, but should be seeing higher numbers from what I have read. I never had any other exhaust on it, only been run with the canister.
I am using the same combo I have read others getting 6800 or 7K with, I was just hoping there might be some other easy fix but probably not

How is that engine running now....just curious! Capt,n

It runs fine, just not enough power for a 18 pound plane Takes around 10 flips to get it running when warm.

Iflyit,

I have a very similar experience as you regarding my TOC 53MM. I have run a couple of gallons through mine now and I have setup on 40:1 using a Xoar 22 x 8. The best numbers I've seen to date have been 6350 RPM. Not nearly the RPM's that others are seeing using the Wildhare hop-up kit and old style mufflers. Mine does have one of the newer mufflers on it and I am running just the stock muffler on my setup.

The throttle range is O.K. on mine, idles great, full-throttle is solid, but lots of burble at just about 3/4 range. I have tried working the needles to remove this but have yet to succeed in getting a smooth transition. I also have mine mounted in a 17.5 lb. airplane and at this point I am near full-throttle through most of my flight (mixed 3D/precision). Hovering requires near full-throttle as well and there is absolutely no way I would bring this airplane for any kind of DOD flying with the rpm's that I am currently getting on this setup.

This motor was acquired from Cermark as well.

Just for a little comparison, I could only get 6680 rpm and that's with a Vess 22A on a well broken in and great running Brison 3.2. With a Menz 22/8 I can get about 7300 rpm on the same engine. In- air performance is barely noticable with the slight edge going to the Vess (vertical). My engine just seems/sounds and feels happier with the Menz though.

Which is why I suggested a change in props. With a Taurus I couldn't obtain decent performance with a Vess or Xoar but a switch to a Menz and NX 22-8 made all the performance difference in the world.

Good to see you back P.R. Between you and Ralph maybe we can restore some order around here!!