problem with OS 46 AX
 

I have been having problems with two 2 year old OS 46 AX engines. The first one will run until I give it three to four clicks up on throttle. Then it completely quits on me. The second one was in the air when I slowly began to lose power. I was at full throttle and I was only getting about a 1/4 of the power. I have changed glow plugs, tried setting the needle valve thinking it may be running rich or lean, and even tried different fuel. Nothing seems to make a difference. I have posted pictures of the engine that was flying at the time of losing power. Has anyone seen this and/or are there any ideas as to what may be causing my problems?

RE: problem with OS 46 AX
 

Insert ;),


This engine clearly seems to have a leak between the head and the sleeve...
It could be that the head, or the sleeve, is warped, or that the head shim is trashed.

Were the head bolts all tight before you removed them?


Try to evenly and gradually re-tighten them and to try starting the engine again.

Before you start it, open the main needle and the low-speed needle significantly from where they are now.

By blowing air through a piece of fuel-line connected to the carburettors nipple, also check if the the flow increases as the throttle is opened further (fuel metering) and at full-throttle, as the main needle is opened further.

The burnt-on castor suggests it has been running hot.

RE: problem with OS 46 AX
 

I don't know about the second engine...

It seems too new to be losing power significantly.

RE: problem with OS 46 AX
 

The headbolts were snug, I didn't have to wrench very hard to remove them. Should I clean all the black off first before putting it back together? I will post pictures of the other engine also. Thanks

RE: problem with OS 46 AX
 

Insert,


I suggest you clean the parts well before reassembly.

It has been said warm anti-freeze over-night will remove the castor gunk pretty well.


You're welcome. That is why we participate in this forum.

RE: problem with OS 46 AX
 

Looks like it may have had a life of running lean as well. DarZeelon is right, there's definitely a leak there.

Double check the fuel tank setup on the other engine. Very often an engine problem is actually a fuel tank problem.

RE: problem with OS 46 AX
 

You can clean with 0000 steel wool, or mothers metal polish, each will work fine.

I would check the rear bearing on each motor, O.S. has used several different bearings, and some of them don't hold up very well.

RE: problem with OS 46 AX
 

Dar is right on.

When you tighten up those head bolts, do one then the one on the opposite side. Criss cross the tightening process to prevent head warpage. Snug is not good enough but do not over do it either. They have to be tight. While you are at it, check the bolts on the back plate too. They need to be just as tight. When aluminum heats up, it expands. You want it to expand evenly as possible.

After your first run, retighten up all the bolts again paying attention to criss cross step by step tightening process. Check the back plate too.

The discoloration out side the engine is cosmetic. You can also try Dawns "Power Dissolver." You can get that at the Super Market, Wal-Mart, etc.. Follow the directions on the container, use an old tooth brush or something similar to scrub with. That too will help clean up the outer surface, but like said, it is cosmetic and has nothing to do with performance except to indicate you had a leak from the head.

Cheers,

Chip

RE: problem with OS 46 AX
 

Thanks! I'll start working on that engine. I pulled the other engine but it looks brand new. Nothing like the one I posted. This is the one after four to five clicks up on the throttle quits on me. Anyone have any ideas as to why it would do that?

RE: problem with OS 46 AX
 

Your going to haft to set your low speed needle ,which won't kill you. Your runing to lean and a HS rich setting won't make up for a too lean low end................

RE: problem with OS 46 AX
 

Thanks speedster 1919.

RE: problem with OS 46 AX
 

.

RE: problem with OS 46 AX
 

Adam,


This more or less says it all...

OS in [link=http://www.osengines.com/faq/product-faq.html#q2]their US dealer's Q&A[/link] and Morgan Fuels, the manufacturer of CruelPower in their web site, both tell you that for engines that have ABC/ABN/AAC piston+sleeve sets, all synthetic lube fuels are NOT recommended. Morgan recommends their own 'Omega' fuels for such engines.

Why can't people understand that!? What part of the clause 'not recommended' don't you understand?


In an effort to keep their planes just a bit less oily, people risk engine damage, inferior reliability, crashing, Etc..

RE: problem with OS 46 AX
 

I have to agree with DAR on this one.

Save the all synthetic fuels for Ringed 2 strokes, or 4 strokes.

RE: problem with OS 46 AX
 

Ditto. Stop using fuels labeled as "all synthetic" immediately. I've seen the innards of a few non-ringed engines that ran such fuel. Not pretty.

RE: problem with OS 46 AX
 

I run Omega with extra castor added for ringed, non ringed, 2 and 4 stroke engines.

If worried about messes, use synthetic car wax on Monokote or Ultracote. It makes wiping it clean an easy job. Waxes with organic compounds like carnuba work well too, but the carnuba breaks down much faster. Auri works really well, but I'm not sure if that is still on the market.

RE: problem with OS 46 AX
 

I never thought about car wax before

RE: problem with OS 46 AX
 

Adam,


I didn't mean to scare you to the point of removing 'the smoking gun'...:D

This time you had to learn from your own mistake.


I hope next time you let others make mistakes and learn from their experience...[8D].
Or better yet, prevent them too from making these mistakes.


A well designed model engine, using the correct fuel, should last 400 hours - not 4 hours...

Using the wrong fuel makes this hobby seem more expensive than it already is.


Cheers.

RE: problem with OS 46 AX
 

Dar,

I wasn't scared, I was annoyed. Nobody here seems to have read my post in it's entirety, so I deleted it. This is a common problem here on RCU, and is the reason why the number next to my name is not very high. Most of the time, I don't want to waste my time.

I appreciate the concern you guys have about running castor oil in engines. It's good insurance. I'm well aware of the ramnifications of running all synthetic fuels, and I chose to accept that risk. Reading the cool power website, they indeed recommend that Omega fuels are run in the ABC/ABN engines, but also they post several testimonials of successful use by people who know how to set their engines up PROPERLY. Just because it's not recommended doesn't mean it can't or shouldn't be done. I've been running CRUEL POWER for years without incident, after switching away from Omega.

If you had thoroughly read my last post, instead of fixating on COOL POWER, you would have seen that I've ran many gallons of this fuel without problem. I also checked all the bolts for tightness, and the COMPRESSION IS NORMAL. I disassembled the engine, and found NO VISIBLE SIGNS OF SCORING OR WEAR. I also indicated that I run the engine 5-6 clicks (minimum) rich of peak.

Today, I cleaned the carb out and reassembled the engine. Re-installed the engine in the airframe, and verified the travel on the carburetor arm. I fired it up, and it's back to normal, maybe even better than before. I suspect that there was either dirt in the carb, or the throttle wasn't completely opening (I had done some radio work recently, but didn't suspect this because the engine was running fine for the first 5 minutes of flying.

The only thing I've confirmed (not so much learned) from this particular forum is that I shouldn't bother to ask if anyone has had similar problems, but that I should just fix it and move on.

I apologize if I sound like a jerk here, but this isn't the first time someone has scolded/flamed/discounted me without bothering to even read what I've written or verify the accuracy of what I've said.

Time and time again on these forums, "experts" take each others word as gospel, without bothering to stop and check what was said for accuracy. Other instances, like here, the "expert" fixates on something they disagree with and starts flaming.

The definition of "expert" on RCU seems to be anyone with more than 1000 posts or so to their credit. I'll never be an RCU "expert" because I generally spend more time flying and less time blowing smoke, and for the reason stated in the beginning of this post... Nobody reads this crap anyway.

You have my permission to quote or even take out of context as much of that as you see fit.

Best Regards,

Adam

RE: problem with OS 46 AX
 

Hi!
Your'e right! Over here in Europe most people do run all their engines on just 10-15% oil...and all synthetich at that!

No one in our club (Around 100 members) does use castor oil anymore and this is not a new "thing" in Europe. We have run our engines this way for decades. So please don't say anymore that 20% castor oil is necessary in a modern engine...becasue it isn't!
32 years in this wonderful hobby!;)

Regards!
Jan Karlsson
Sweden

RE: problem with OS 46 AX
 

I don't recall anyone mentioning running all castor for lube oil in their fuel. I would never think about flying FAI because of that rule for FAI fuel.

RE: problem with OS 46 AX
 

Adam,


To some more experienced people in this forum, seeing a certain statement in a post, does make its remainder 'illegible'; as did the 'Cruel Power' statement in yours.

It seems to be a tendency to blame the first mistake one sees for the entire problem.


As Jan Karlsson (JAKA) wrote, there are synthetic oils out there that CAN be used in non-ring engines.
Jan is talking about Motul Micro, Sachs Aerosynth II/III and Sachs Aerosave, which have lubricity that even exceeds that of castor oil.

These oils are not marketed in the USA and those that are, like CoolPower and Klotz, are inferior to castor oil by their own admission (read the tech notes).


The only US available lube which does excel is [link=http://www.cooperfuels.com/airfuel_2.htm]Cooper Fuels[/link] ester base synthetic.


But all those synthetics I mentioned still have a flash-point which is much lower than castor oil, which means even with their great lubricity, they will offer less hot protection.


Good old degummed castor oil is still the only lubricant for extreme conditions.

RE: problem with OS 46 AX
 

What's called FAI fuel is only necessary in a couple of FAI events where absolute power is a determining factor. In CL this is for 2.5cc speed, in RC this is for Pylon and I believe one event in free flight. The sole purpose is to level the playing field as far as possible so that secret and probably dangerous fuels can't be used to gain an advantage. For all other events you run what you brung :). OK, I think CL combat is now limited to a max of 10% nitro but basically in anything except those 3 events I mentioned there's no limitation on fuels.

Personally I'm glad I don't have to fly CL stunt using the rather silly AMA rules :D.

RE: problem with OS 46 AX
 

Adam I never got a chance to read your post. The testimonials you quote are guys that are factory sponcered and and or change engines every year and often.............I mix my own fuel and I get static because I come to the field with different colors and only run 5% nitro. I checked into european oils here in the USA but at 3-4 times the price plus shipping ,they are not cost effective. There are 2 members at my club that push their cruel power 15% on everybody and the dirty little secret is they have lots of bad bearing engines at home. But they swear by Cool Power to the death.

RE: problem with OS 46 AX
 

Downunder- I was trying to point out the extreme ends of the castor oil debate in hopes of ending it in this thread.

The problem looks like a head gasket leak which is probably not related to a brand of fuel, or claims of what is being used in other countries. I'm interested now in how the engine will run after a new gasket.