Have a Webra 32 in my Outlaw with mouse can pipe APC 8x7 prop. Cool Power 10% fuel OS#8 plug. Engine ran good but would burn glow plugs after a couple of flights (I thought it was due to the 10%nitro ). Plane stored 18 months while we moved and built a home. Dispite the motor being well lubed she was gummed up and would not run. So took it apart and cleaned it well and replaced all the O rings and placed a .2mm shim to decrease compression. Since Horizon shorted me the O ring to the high end needle. I just got a new needle with the O ring on it.

Got her on the stand today Same 10% fuel, Prop tried an OS#3 plug as I thought a colder plug would hold up better. Set the needles per Webra both high and low needles out 2.5 turns. The engine wouldn't start. Seemed like it was flooding and it was. Changed to a Fox Miracle plug Leaning the high needle got the engine running rough 4 cycle about one turn out. Leaning the engine and it was just "getting on the pipe" when I completely screwed in the needle. Still ran with lots of smoke and not overheating. I believe one or two more clicks lean and she would have been fine if I could have. Didn't touch the low end and check idle as I want to settle this issue first.

Is the spraybar bad???? Ideas?

Pete

G'day Mate
First off, if the oil content was Coolpower with no Castor, it would not be gummed up, so I suspect Castor in there somewhere, & what % oil are we talking.
2, did you run the motor dry after last use, & put after run oil in it?, I think not!
3, 10% nitro will not need a colder plug, only when you get to 20 or 30%.
4, a OS A3 is a hotter plug than a #8.
http://www.os-engines.co.jp/english/...g/pluindex.htm
5, you probably have been running the motor too lean, causing very high temps, which will destroy plugs, or you have an issue inside the motor, ie, bearings failing, causing plugs to fail.
6, Is it possible that your fuel could be contaminated?
You stated that it had been 18 months since last use.
Try some new FRESH fuel & see if that helps.

Alan,

Did run motor dry and used lots of after run oil. When it would not run before rebuild I assumed it was gummed or blocked or an air leak from dried out O rings, etc. Same thing happened on my RCV 90 in storage, Took it apart cleaned it and it ran like a top. My bad on the A3 I used it because it was hotter than the #8 sry. The inside of the engine is perfect nothing scorched the bearings smooth. Had not wanted to have different types of fuel as my other engines love the Cool Power 10% nitro. I thouhgt adding the shim would fix that issue.

Pics of the stand. needles and spraybar assembly

Pete

Well besides carb is on bass-ak-words. Pipes tend to burn out plugs faster with your HS needle in too far tells me your LS needle is still a little rich. With the pipe and 10% on a webra a miricle plug is too hot. Try a Fox RCLONG or Standard LONG or stay with OS 8.

It's hard to see but it looks like your HS needle spring clip is there. If it isn't some needles self adjust while running. And if your prop is such a load and you barely get on pipe staticly on the ground and in the air you really unload and get on pipe more your going to burn more plugs without being richer.

The mousse can pipe will not burn out plugs. Webra HS and LS needles interact a lot, and my opinion is your low end is very rich. Try the McCoy MC9 plug. It's a tough plug that I've used in my Webra and OS engines for years.

Dr.1

PS Turn the carb around the right way, too.

Thanks for all the responses.

The carb was turned around because on an Outlaw it's side mounted and this puts the needle on the proper side.

Played with it some more with the same fuel it's good. Needle clip is there. Leaned better this time got 15750 rpms with the 8x7 prop. Pinched the line and it it died backed off 3 clicks and pinch test was good. Then set the low end Waaaay to rich. Didn't get a good idle and decent transition until for well over 1 1/3 turn in. Nothing really changed from earlier can't explain the improvement.

It's good enough to mount and test fly. Even when she ran her best it would take a second or two to unload on the pipe. The sweet spot must be really narrow between rich and lean with this setup. I continue to use the 8x7 because of the good pull you get when tossing the Outlaw for launch.

Pete

Hi!
I think you use too much nitro and set the engine too lean! And how about the lengy of that exhaust tube...seems very long too me.

Try 80/20 fuel and a Rossi 3,4,5 or 6 glowplug and see what happens.The Rossi glowplugs are some of the best plugs available (Webra use the Rossi 3 as standard plug on their Webra .40GT engines but call it a Webra plug... ).
Rossi 6 was the plug of choice over here when we flew Sport 40 pylon in the nineties using MVVS , Irvine and Webra engines. Props used were APC 9x7, 9x6,5 and 9x6...we also tried some of the APC 8" pylonracing props with no better performance. My MVVS Q-500 6,5cc engine running a Rossi 6 plug, 80/20 fuel turned a 9x7 at around 17000-175000rpm and a 9x6 APC at 18500 on the same plug.

Are you sure the webra engines are set up to run on 10% nitro? An OS 8 plug is definitely too hot when running on a pipe! Try a MVVS minipipe( short or long).40pipe and see if that will improve things.

When I raced those engines (MVVS and Irvine) I had a fairly broad range and setting them were no problem (we used 6oz Tettra "bubbleless" tanks).
Using the pinch metod isn't the best metode of setting a racing engine...don't know any racer that uses that metode.
Best way is to learn setting engines by ear!

Jaka,

Thanks for the tips. It's been my understanding that Webra's don't need lot's of nitro to run well due to their high compression. I added the shim to see to see if she will run as well without burning out plugs. On the stand pinch testing is good way to see if your too lean. Also use a tach and ears.

Been windy and cold may be awhile before she's in the air.

Pete

This is stepping into oil territory, but if I'm not mistaken Webra specifies that only castor be used in the fuel. Webras are built with really tight pistons due to them being a high compression motor built primarily for non-nitro use. Could it be that its simply overheating with the lack of castor oil in the fuel? Or is the can muffler providing not enough exhaust gasses to escape causing too much backpressure and heat?

I was thinking along these lines and that's why I added the 0.2mm shim.


Jaka,

Was able to get some #5 Rossi glow plugs and will try them out.


Pete