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What'd I do??

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Old 03-18-2003, 01:06 AM
  #1
Ragwing
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Default What'd I do??

Howdy,
Well I really did it this time, I was attempting to break in my brand new Cox Texaco, end result --> something is binding internally. Here's what I did:
When I got the engine I removed the spring starter, intending to use my Sullivan Hornet 1/2A starter-which I did use. Had everything set up properly (I think-second engine and first Cox ): I filled the tank (Powermaster 15%), I primed the cylinder with a drop of fuel and opened the needle valve 3-3.5 turns. I flicked the engine through by hand a couple of times, and then turned the engine back wards until it came up against the compression stroke. I connected the glow starter, then started to turn the engine over with the starter and nothing happened. I turned the engine over for about 10 seconds, then paused, disconnected the glow starter, turned the engine over by hand, hooked things up again and tried again. I must have done that a dozen times.
Frustrated, I took the head off to see if the cylinder was getting fuel, and to check the glow element. The cylinder didn't have any standing fuel, and the glow plug lit up fine. I increased the juice to the glow plug a bit, and added another drop of fuel to the cylinder. Put it back together and tried again-still nothing.
About this time I noticed little specks of silver/gray liquid around where the prop drive plate and the crankcase meet. I figured this was normal, it was break in after all and the presence of liquid indicated that fuel was getting in there and lubing everything. So I kept going, in 10 sec intervals.
All of the sudden-wham! The silicon insert flew out of the starter cone, and the prop stopped suddenly. I disconnected the glow clip, and tried to turn the thing over by hand, but there was a lot of resistance. Fearing hydraulic lock I took the head off, but it looked the same as it always had, just damp-a very light trace of fuel in the cylinder. With the head off the engine still wouldn't turn over without a lot of resistance-so I didn't turn it through very far-just enough to determine that the piston was connected to the crank still.
What did I do? Was I a flaming idiot to use the electric starter? I haven't torn the thing apart yet-but I can't see as how I'm going to get out of this mess without spending more money. It kinda seems to me that the bearing must have seized or something. But I don't know, what do you think? I know how to take the major assemblies apart, but how do you pull the crankshaft? If I bent a rod, how would I go about removing the rod from the ball joint? I've got a Baby Bombshell one week of devoted labor away from flying and this is the start of spring break-help me please! Thanks for the input guys!

Derek
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Old 03-18-2003, 01:25 AM
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Default Cox

You may have seized the crank from no lube getting to it you will have to take it apart to find out, if it is the Rod them you must replace the piston and rod set they don't come apart, with good glow and fuel being primed into the exhaust port I find it some what weird that it didn't at least fire and burn the primer
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Old 03-18-2003, 01:45 AM
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Default Arggg....

Sounds to me like you galled the crankcase/crank fit.

My suggestion would be to use the included wrenches to carefully remove the cylinder (you should find two 'flats' on top of the cylinder that the wrench will grab) and then, remove the tank.

Once you have this done, you can remove the piston/rod assembly and inspect it.
Next, inspect the reed holder area on the front of the tank. Look for scarring or abrasion.
Finally, you can carefully flip over the prop. If it is in fact binding, you have probably galled the crankcase.

If you want to remove the crank, do a search on this forum for 'crankcase' or 'crank removal', and you should find a good description by DickeyBird on removing the crank....

Good luck.
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Old 03-18-2003, 02:54 AM
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Default What'd I do??

Thanks guys, just removed everything that I could, rod is straight and with the cylnder off and piston out the crank still won't turn so I guess I galled it. I'll do the search and remove the crank tonite (hopefully). For the future: how can I avoid this? I'll inspect the reed, but as fastlash mentioned, I should have gotten some pop from the primer. Anything obvioulsly wrong with my methods? Thanks!
Derek
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Old 03-18-2003, 02:56 AM
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Default What'd I do??

I agree with matchless, check the crank. I did that on a norvel once. drove crank out, polished metal off the crank w/ 400# paper, reinstalled and it was fine. but now I always goop the crank up good before I spin 'em!
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Old 03-18-2003, 01:00 PM
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Default What'd I do??

Let the scribes duly note fastlash's honest and accurate answer to a Cox question. Admirable!
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Old 03-18-2003, 01:23 PM
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Default What'd I do??

hey ragwing, the only other thing I can think of is on the Norvel manual,, they say some fuels will coat and contaminate the glow wire so that it burns and looks fine but wont ignite the fuel ... byrons in particular. dont know about powermaster but it has to do with the additives........have you got a new glow plug you could try...or other fuel?...2fast4u is the resident norvel guru and dickeybird is the same for the cox engines.. unless your needle was closed all the way I dont see how you didnt get a run of a second or 2 with the prime, cox's usually pop pretty easily... Rog
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Old 03-18-2003, 01:46 PM
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Default What'd I do??

I would also check to see that fuel is able to follow the path to the head. (Make sure there are no manufacturing 'clogs' in the system) If fuel was hooked up, and head was primed, maybe the path is clogged up. Maybe the fuel line to the engine is kinked. I don't have a clue how this Cox engine gets its fuel, but I'm trying to help. If all else fails, get a Norvel!!! Sorry, I just had to....
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Old 03-18-2003, 02:06 PM
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Default What'd I do??

Sounds like you have indeed galled the crankshaft which can probably be fixed. As far as starting, an electric starter will many times increase starting difficulties on Coxes. I use one but I don't grind away on it for long periods. A spring starter is best until you're familiar with running your Cox engine.

If you're using a power panel to heat the glow plug and the starter shares the same battery, many times the voltage drop when the starter is engaged will cause the plug to cool down. I use a separate 5AH nicad to heat the plug and only use the inertia of the spinning starter to spin the engine, ie: hit the starter button away from the engine, release the button and hit the spinner with the "coasting" starter.

When you have your binding problem solved, try starting by hand. The worst that will happen (if you're careful) is that it will start backwards; at least it will be running. If you have a good hot glow, and a few drops of prime, it HAS to run in a short burst until you get the needle right! Use a balled up rag to stop it if it starts backward....please don't stick it in the dirt to stop it!

By the way 2fast, sounds like he got the Texaco to enter a Texaco event; no N..N..N..No..Nor..Norvels allowed!
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Old 03-18-2003, 04:55 PM
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Thanks for the help! I pulled the crank off last night and, as you all suspected, the front bearing was galled, so I sanded it down with 400 grit and a little bit of fine steel wool. Cleaned and lubed and put it back together, seems to turn fine now. Looked the whole engine over as I re-assembled it but there wasn't anything obviousl the matter with it. I'll see if I can't get out and try starting it again today. I'll turn it over by hand, and I'd use a different fuel but Powermaster is all that is sold in town so thats all I have. Thanks again, and I'll let ya know how it goes.

Derek
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Old 03-18-2003, 05:25 PM
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Default What'd I do??

Ragwing,
I have tons of cox crankcase/shafts in my parts box. If you want a NIP one (free) just email me.

If you can get one locally thats fine, but dont go and order one for outrageous prices. Let me help you out. Get that baby bombshell in the sky!

acoholic@nt.net

Andrew Coholic
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Old 03-18-2003, 10:20 PM
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All-right. It works, ran 5 tanks through it. Turned out I had to open the needle valve more, 5.5 turns plus primer seemed to do the trick. I'm not able to start it consistently with my gloved finger, it likes to flip flop, running forward then backward but never passing compression. Bumping the engine with the starter does the trick. I got a lot of gray oil and fuel coming out of the gap between the drive plate and the crankcase though. Somthings wearing. It seemed to get better as time went on though. Thanks for all your help guys, and Andrew thanks again for your generous offer!
Back to the building board.
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Old 03-19-2003, 03:38 AM
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Default What'd I do??

If it likes to flip flop, you might put another head shim in it to retard the timing a little. and a lot of times with a starter you will not know if it is running until you pull the starter off! bumping is best.
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Old 03-22-2003, 04:05 PM
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Hi there.I have been doing rc for about twenty year.I found when breaking in an engine or even if you have a tight engine like a norvel,I warm the head with a tiny torch before my initial start.At this time I am running a norvel 15,so I warm the head ,just luke warm,bring the fuel up to the carb,connect my glow starter and give it a flip.I rarely use a starter.By using a starter you are pushing the prop hub against the crank case.Running the starter for more then a couple seconds can quickly cause some serious heat and wear.So for you norvel guys reading this,it might I only said might solve alot of these problems we read about.
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Old 03-24-2003, 03:54 AM
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Derek,

All your problems stem from using an electric starter. All the Cox reed valve engines, as far as I know, do not have a washer between the prop drive washer and the crankcase. Using the starter, you are grinding soft aluminum against soft aluminum. This galls the case at the front. That's why you got the grey residue initially and why you are still getting it. Continuing to use the starter might cause further problems.

I have a supply of the steel washers as are used on Cox TD engines. Let me have your address and I'll get one out to you

Redneck is on the right track. However, all Norvels use a steel washer.
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Old 03-24-2003, 05:56 AM
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Default That makes sense.

Thanks for the help guys! Will the washer adversley affect the conrod and crank connection or the clearence between crank and the crankcase? I guess the driveplate just won't go onto the crankshaft quite as far. Thanks 1705493! I'll send you a pm.

While we're at it, is there a cheap substitute for a head gasket. Some relativley common washer? They're not on the Cox parts list, but I know I can get them from competitionma.com, I just don't really want to pay shipping--I'm cheap .

Derek
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Old 03-24-2003, 02:45 PM
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Derek,

I'll send you the steel washer along with a few spare glow washers.

The steel washer won't affect any clearances because it butts against the crankshaft and is pinched by the drive washer. You'll see when you get it. Going out today.
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