[CanajunFlyBoy]

I have a fairly new OS FX 1.60 which I broke in by running it very rich and all the normal stuff. When it came time to start leaning it out last year I did so but after two flights I noticed that the engine was really HOT. Upon discussion I learned that I needed a bigger air exit hole from the cowl (a CG Monster Pitts) which I promptly made. It made a huge difference in terms of coolness of the engine.

My concern is that I cooked something last year because this year I notice that after just two flights I can wiggle the prop at the front bearing a little bit. After it cools there is no free play but right after the second flight...well, there's free play.

Did I cook a bearing? If so, what can I do now? Send it in to OS?

Any comments or suggestions welcome.

Thanks,

CFB

[SJrcflyer]

Well some play is normal, but if you want take the engine apart. Have a look at the top of the piston, look for any pitting, if your really concerned about the bearings, change them. Its a 15min job.

[volksman]

thermal epansion is causing the end play if the bearings are smooth dont worry about it

[eduardo]

I'll continue with a somewhat similar issue. I have a low time (2 -3 jugs) O.S. 1.60 with a Bisson Pitts type muffler on a 73 in Extra 300. Ran like a swiss watch all summer, and then this past weekend I had four deadsticks in a row out of nowhere. All occurred within the first 2 -3 min of flight. I was able to recover three of them, but the last one was was low and far, and unfortunately I crashed the model cracking the fuselage. I'm not too concerned with the loss of the airframe as I am about the cause of the successive deadsticks. I tried all the logical things: new plug, fresh fuel, open the needle valve a click or two, but nothing. I haven't had a chance to inspect the fuel tank yet, but externally it appears that the clunk is still attached to the uptake tube. Has anyone ever experienced something similar? I refuse to give up on this engine just yet.

Eduardo

[JimMcIntyre]

Have you tried flushing the needle assembly?

i.e. remove the needle valve and pump some fuel through?

[AJCoholic]

Originally Posted by eduardo

I'll continue with a somewhat similar issue. I have a low time (2 -3 jugs) O.S. 1.60 with a Bisson Pitts type muffler on a 73 in Extra 300. Ran like a swiss watch all summer, and then this past weekend I had four deadsticks in a row out of nowhere. All occurred within the first 2 -3 min of flight. I was able to recover three of them, but the last one was was low and far, and unfortunately I crashed the model cracking the fuselage. I'm not too concerned with the loss of the airframe as I am about the cause of the successive deadsticks. I tried all the logical things: new plug, fresh fuel, open the needle valve a click or two, but nothing. I haven't had a chance to inspect the fuel tank yet, but externally it appears that the clunk is still attached to the uptake tube. Has anyone ever experienced something similar? I refuse to give up on this engine just yet.

Eduardo

Eduardo,
I had a similar situation a few years ago - and found the problem was the clunk pickup line had cracked just after the brass tank tube. It would suck fuel for a few minutes untill the fuel level fell below the tank bung then suck air and die. I replumbed the lines, fluched the carb, etc etc but not untill I finally took the tank apart and saw the line with a partial rip in the line did I figure out what was happening.

It may not be your problem but its worth a look.

AJC

[eduardo]

Jim and Andrew: Both of you make very valid points. I have actually flushed the needle valve assembly with a syringe and air does flow through it, apparently in a normal fashion. However I have not taken the tank apart, so until I do a post mortem on the tank I won't know what the problem is. I suppose if everything appears normal with the tank, the next step is to start looking at the engine internally, although I dread that possibility since I have no experience taking one apart. Hopefully it doesn't come down to that. Thanks again guys.

Eduardo

[eduardo]

Dear CFB: I forgot in all of this that I probably owe you an apology for unintentionally hijacking your thread. On second thought, I probably should have started an independent one. Therefore please accept my apologies.

Eduardo

[CanajunFlyBoy]

I had a similar problem once and it turned out to be a pinhole in the fuel line inside the fuel tank right where it goes onto the brass tubing. You could only see it if you flexed the tubing at that point.

Basically as soon as the fuel dropped to the tubing level she started suckin' air....

CFB

[CanajunFlyBoy]

Hi Eduardo,

Hey, no need to apologize. I noticed that Andrew mentioned the exact same issue as I mentioned.

Great minds think alike eh?

I hope it's your fuel pickup line becuase if it isn't then you've got a gremlin.

Cheers,

CFB