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Golden Bee Troubles

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Golden Bee Troubles

Post  Sig Skyray on Mon Jun 08, 2015 1:26 pm

Just bought my first Golden Bee, used.  Geez, I was excited to crank it up but the excitement quickly waned.
I think I might have some serious troubles. I hope I didn't waste my money!!  Burning Cash

The components:
Nice shiny gold 8cc stunt tank and crankcase. Small brass round drive plate.
#1 stamped inside the exhaust port on cylinder. No cutout on top fin of cylinder for wrench.
Nice wide SPI gap.
Galbreath head.
Killer bee crank.
Steel reed.
5x3 prop. (Decided to include a picture of it below.)

The engine had a lot of compression but not excessive I thought and it all looked good but I noticed what seemed to me to be excessive play on the crankshaft rotation when the piston was moving through TDC or BDC.  Just seemed like the crank would turn too many degrees before the piston reversed direction.

Screwed it onto the test stand and it started right up.

It ran well for about 1 1/2 minutes before the prop flew off.  Luckily it neither me or my son.  The engine, to my surprise, kept running.  It took me about 5 seconds to turn the needle valve down to Kill it.  Before the prop let loose I clocked it at 15,300 RPM.

What I found was: 4 very loose engine mounting screws and a loose cylinder, ad obviously the prop screw backed all the way out.  I'm not sure what caused this but I do know the engine mount screws and the prop were tight.  I had the head off so that was tight but may not have checked the cylinder.  So which came loose first?

After checking over the parts I decided to give it another run.  The engine will now only run at a very low RPM regardless of what I do with the needle.  I have a video of it and can post if needed.  It does seem to have a good amount of play on the crank when pulled and pushed in and out of the case but I tried to tighten that up with no luck.  I'm wondering if it's sucking air through the front.

Anyway, the ball and socket play on the piston is still a lot but still shows good SPI gap at TDC.

Will these engines sustain damage if run without a prop?  Anybody have an idea of what's up?  
The drive plate is the smallest I've seen... does that indicate that it's older?
Greg

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Re: Golden Bee Troubles

Post  pkrankow on Mon Jun 08, 2015 1:40 pm

It is probably fine.  The engine reversed direction which is why the prop came off.  The mountings came loose first.  

The cylinder loosed from heating.  This is pretty normal.  Hand tighten it while warm.  The head is likely loose too.

Forward to back play is generally not an issue.  There are washers available that can go in between the drive plate and crank case to take up the play some if the play is really excessive.

The piston probably needs a reset as there is some extra play in the ball socket.

The drive plate is for a no-drag spring start.

Next time OPEN the needle.  Flooding is safer on the engine.  Yes running without a prop is bad on the engine.  It is an instant lean run.

Phil
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Re: Golden Bee Troubles

Post  Cribbs74 on Mon Jun 08, 2015 1:49 pm

Let me answer with a couple questions..Wink

Was it vibrating excessively when you ran it the first time? Was the prop balanced?

It is very possible it wasn't mounted hard enough. That said it looks like you have a Glo-bee head and not a Nelson. How many shims under the head? Don't be to concerened about in and out play, but be more concerned about side to side play.

Yes you can damage an engine with a shaft run, but I have never seen it happen with the shaft runs I have done myself.

Check to make sure the rod is not bent, crankpin is not bent and see it the crank is still true.

Post back and we can go from there.

Ron

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Re: Golden Bee Troubles

Post  TDbandit on Mon Jun 08, 2015 2:00 pm

First of all Phil hit the nail right on the head with his advice. One thing I'm gonna add about the prop, if you get an engine with a prop on it always make sure it is tight before starting a lot of times it is on some what loose.
Another thing just learned something I've never heard of a cox reedie suffering a no load runaway that sucker must of hit serious rpm so like Phil stated always open the needle to flood it out when in a situation like this if you close the needle not only will the lean condition caused by the run away get worse but will increase rpm before it stops greatly increasing damage potential by opening the needle by opening the needle not only does it cool the engine and add lubercation which helps save parts but it slows the engine down before it stops which is what you want it to do. Again as Phil stated I would perform a piston reset too excessive play messes with port timing and check the case for egging which can accur in a runaway. (Bandit)
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Re: Golden Bee Troubles

Post  Sig Skyray on Tue Jun 09, 2015 8:51 am

Cribbs74 wrote:Let me answer with a couple questions..Wink
Was it vibrating excessively when you ran it the first time? Was the prop balanced?

It is very possible it wasn't mounted hard enough. That said it looks like you have a Glo-bee head and not a Nelson. How many shims under the head?  Don't be to concerened about in and out play, but be more concerned about side to side play.

Yes you can damage an engine with a shaft run, but I have never seen it happen with the shaft runs I have done myself.

Check to make sure the rod is not bent, crankpin is not bent and see it the crank is still true.
Post back and we can go from there.
Ron

Thanks Bandit, Phil & Ron.  What's case egging?  Everything looks round. Where will it egg?

Yes Phil, I did forget to say the engine was running backwards. Is it advised to shut those bench test runs down?
Phil, you say to hand-tighten the cylinder while it's warm. (I assume you mean with a wrench???)  That's good advice, and I just read in another thread to always use heat when disassembling.

Ron:  I used a new 5x3 prop and the balance seems fine but I don't own a balancer and have not researched the method yet.  It was not vibrating a lot but maybe slightly more than my other engines.
Yes, you're probably right that I needed stronger mount screws.  I'll make that change.

I would like to know what kind of head I have and have provided a picture.

There is one head gasket.

There's a decent amount of in and out play, not excessive, and very, very little side-to-side. Hardly detectable.

The rod looks straight, the crank looks true and the crank pin all seems fine.  I cannot detect any play between the crank pin and rod but the ball socket on the piston is way loose.  I just bought a reset tool from Bernie and have not used it yet.  People have mentioned mushrooming a few so I'm a bit apprehensive until I read up on that.

So what kind of head do I have, what the heck is "case egging" and what should I try before giving it another test run?  Should I use a 6x3 prop next time to slow it down a bit? I have a 5x4 too. The low RPM runs were odd.

Greg

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Re: Golden Bee Troubles

Post  TDbandit on Tue Jun 09, 2015 9:15 am

Case egging is caused by the up and down movement of the crankshaft it eggs out the crankcase easy way to check it is move the crankshaft up and down and left and right its normal to have a little but what you don't want is excessive.play.
(Bandit)
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Re: Golden Bee Troubles

Post  KariFS on Tue Jun 09, 2015 10:43 am

That's a Glo-Bee head, like Ron said. I have a couple of those new in bag, and it says "Glo-Bee" on them.

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Re: Golden Bee Troubles

Post  pkrankow on Tue Jun 09, 2015 1:02 pm

When I say hand tighten, I mean use your hand and tighten it. No wrench necessary, but it is hot so a rag is in order. If it is good and warm it will lock up when it cools, and stay tight enough when hot.

Use a wrench on the head only, this will also tighten the cylinder to case.

Egging is in the main bearing. Side to side play will increase. The main can be pretty far worn out and the engine still run well. The crank may have notable side play in all directions, but it usually develops more play in one direction than any other (typically in line with the cylinder). Don't expect peak performance out of it though if this happens.

Egging can be "fixed" by a machinist. The case is bored out, sleeved with bronze or brass, then the new metal is bored to tolerance. This is typically done by the owner as the cost of labor is very high compared to the cost of replacement parts. A small "hobby" engine lathe is capable of all operations, with some good measuring devices and basic knowledge of shrink fit. I do not recommend it as a first project, but it does qualify as a "student" level project.

Phil
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Re: Golden Bee Troubles

Post  RknRusty on Tue Jun 09, 2015 10:15 pm

That Glo Bee head should probably have at least 3 copper gaskets, never any less until it's old and severely losing compression. Start with 5 gaskets and work down till you get the best performance. They're good head/plug combos, just higher compression than Cox originals. I prefer the finned head clamps, also from Bernie and Merlin, especially in hot weather. I recommend prop screws that are long enough to go deep into the crankshaft, just short of bottoming out. It's more secure and also keeps the splined end from breaking off. The stud and barrel nut that Bernie and Matt sell will do the trick, and they will accept the plastic snap-on spinners. I also use black oxide hex head(allen) bolts.
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Re: Golden Bee Troubles

Post  Sig Skyray on Sun Jun 14, 2015 7:03 am

Alright, I got to working on this engine yesterday.
I thought I tightened the cylinder after the prop flew but maybe not.

I added 3 more head gaskets and tightened everything up and it runs well so the engine is not damaged. Oh, and I reset the piston, the rod had a lot of slop.

Here's the thing... the engine runs 30 seconds and quits. I've got an 8cc tank on it with the fuel line at 9 o'clock. It seems like it warms up and quits. I've tried different glow heads, changed the reed, tried 2 gaskets vs. 4 on the glo bee head...

Any ideas?
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Re: Golden Bee Troubles

Post  rogermharris on Sun Jun 14, 2015 7:18 am

Sig Skyray wrote:Alright, I got to working on this engine yesterday.
I thought I tightened the cylinder after the prop flew but maybe not.

I added 3 more head gaskets and tightened everything up and it runs well so the engine is not damaged.  Oh, and I reset the piston, the rod had a lot of slop.

Here's the thing... the engine runs 30 seconds and quits.  I've got an 8cc tank on it with the fuel line at 9 o'clock.  It seems like it warms up and quits.  I've tried different glow heads, changed the reed, tried 2 gaskets vs. 4 on the glo bee head...

Any ideas?

may bee a dumb question but are you holding it sideways?  it won't pick up all the fuel otherwise.

whats with the head gasket stacking?  i have never run a modified motor where the compression would bee an issue and i need to invest in one of those piston reset tools...
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Re: Golden Bee Troubles

Post  getback on Sun Jun 14, 2015 8:27 am

I hope you end play isn't like this one , All new stuff killer bee set up and I never got it to run Sad
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Re: Golden Bee Troubles

Post  Cribbs74 on Sun Jun 14, 2015 9:46 am

Sig Skyray wrote:Alright, I got to working on this engine yesterday.
I thought I tightened the cylinder after the prop flew but maybe not.

I added 3 more head gaskets and tightened everything up and it runs well so the engine is not damaged.  Oh, and I reset the piston, the rod had a lot of slop.

Here's the thing... the engine runs 30 seconds and quits.  I've got an 8cc tank on it with the fuel line at 9 o'clock.  It seems like it warms up and quits.  I've tried different glow heads, changed the reed, tried 2 gaskets vs. 4 on the glo bee head...

Any ideas?

The pickup being at 9 o'clock will only allow a short run until the fuel level reaches the pickup.

When bench running put the pickup at the 6 o'clock position. Glad you were able to sort things out. Time to mount it on something. If you plan on flying CL be sure to put the pickup back to 9.
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Re: Golden Bee Troubles

Post  roddie on Sun Jun 14, 2015 10:29 am

rogermharris wrote:
Sig Skyray wrote:Alright, I got to working on this engine yesterday.
I thought I tightened the cylinder after the prop flew but maybe not.

I added 3 more head gaskets and tightened everything up and it runs well so the engine is not damaged.  Oh, and I reset the piston, the rod had a lot of slop.

Here's the thing... the engine runs 30 seconds and quits.  I've got an 8cc tank on it with the fuel line at 9 o'clock.  It seems like it warms up and quits.  I've tried different glow heads, changed the reed, tried 2 gaskets vs. 4 on the glo bee head...

Any ideas?

may bee a dumb question but are you holding it sideways?  it won't pick up all the fuel otherwise.

whats with the head gasket stacking?  i have never run a modified motor where the compression would bee an issue and i need to invest in one of those piston reset tools...

Rog, I never knew about the multiple head gasket thing until joining CEF. Rusty mentioned (above reply) that the Glo-Bee head/plug combo, is of a higher-compression design than what would have come stock on a Bee-style engine.. and if you're trying one on a Bee that has a good cyl./piston fit... you'll likely need to back-off the compression with adding gaskets. On my next Cox parts order.. I'm planning on buying extra gaskets.. and some high-compression heads. Like Rusty mentioned; (and a great tip btw..) you may wake-up a tired old Bee by trying this.

Make sure if you obtain a rod-reset tool; that you glance through threads on the subject here on the forum. There are some "do's and don'ts".. but just a couple points I've taken; Follow the tools instructions.. and use "light-taps" with a small hammer while rotating the piston in the holder every tap or two; constantly checking for "play" in the joint. The tool's holder should be placed on a firm hard surface such as an anvil on a bench-vise. This gives you a better feedback-feel while resetting. Too tight of a joint-fit should be avoided. What "I" do is; de-gum the piston/rod with solvent, observe the slop in the ball-socket joint by gently flicking it around with my finger in between taps with the hammer. I don't use any oil on the ball/socket joint until I reassemble the engine. I try for a fit where the rod will only move from a position when physically shaken.. and doesn't drop with gravity when holding the piston horizontally. Maybe that's not tight-enough.. but it's the way I do it.

Greg, A couple of questions; does your fuel pick-up line have an internal spring? Some people feel that it's important to have it in place. Have you tried installing a fuel-tubing seal over the needle-shaft where it enters the back-plate? You could have a fuel-draw issue (an air-leak?) that doesn't present itself until the level in the tank drops a bit.
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Re: Golden Bee Troubles

Post  roddie on Sun Jun 14, 2015 10:34 am

Forgot to ask Greg.. does the engine gradually go "lean" before it quits?
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Re: Golden Bee Troubles

Post  Ken Cook on Sun Jun 14, 2015 2:51 pm

Have you tried a stock glow plug vs the Glo-Bee? There were a couple different versions of the Glo Bee, sport and racing and one more type. Appearance wise on the outside they look the same, but the combustion chamber is different. Yours appear to be a sport if memory serves me correctly. What nitro fuel are you using? I would certainly try and bump it up for a test if you have some. 35% minimum with that plug as it sounds like the plug is cooling off. A smaller prop like a 5x3 as well.  They can be notorious for taking a dump. I like them, but they're not very reliable. Even though the plug lights up, it can give you all kinds of funny business. I would re try using a standard Cox plug. Ken
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Re: Golden Bee Troubles

Post  Sig Skyray on Mon Jun 15, 2015 3:17 pm

rogermharris wrote:

may bee a dumb question but are you holding it sideways?  it won't pick up all the fuel otherwise.

whats with the head gasket stacking?  i have never run a modified motor where the compression would bee an issue and i need to invest in one of those piston reset tools...

Thank you Roger.  Well... no, I'm not holding it sideways.  I figured with that much fuel in the tank I should get more than 30 seconds.  If it cools a minute or two and I restart, without refueling, it runs 15 seconds and quits.  I suppose it could be foaming in the tank and sucking some air.  Further testing is needed.

Sharing another Rusty trick: add ArmorAll to the fuel to lessen or stop the foaming.  I just learned that, did not try yet.

On the multiple gaskets... it's to reduce compression when using a high comp head. With one gasket it has almost too much compression. The reset tool worked very well.

I'll report back.  Greg
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Re: Golden Bee Troubles

Post  Sig Skyray on Mon Jun 15, 2015 3:26 pm

roddie wrote:

Rog, I never knew about the multiple head gasket thing until joining CEF. Rusty mentioned (above reply) that the Glo-Bee head/plug combo, is of a higher-compression design than what would have come stock on a Bee-style engine.. and if you're trying one on a Bee that has a good cyl./piston fit... you'll likely need to back-off the compression with adding gaskets. On my next Cox parts order.. I'm planning on buying extra gaskets.. and some high-compression heads. Like Rusty mentioned; (and a great tip btw..) you may wake-up a tired old Bee by trying this.

Make sure if you obtain a rod-reset tool; that you glance through threads on the subject here on the forum. There are some "do's and don'ts".. but just a couple points I've taken; Follow the tools instructions.. and use "light-taps" with a small hammer while rotating the piston in the holder every tap or two; constantly checking for "play" in the joint. The tool's holder should be placed on a firm hard surface such as an anvil on a bench-vise. This gives you a better feedback-feel while resetting. Too tight of a joint-fit should be avoided. What "I" do is; de-gum the piston/rod with solvent, observe the slop in the ball-socket joint by gently flicking it around with my finger in between taps with the hammer. I don't use any oil on the ball/socket joint until I reassemble the engine. I try for a fit where the rod will only move from a position when physically shaken.. and doesn't drop with gravity when holding the piston horizontally. Maybe that's not tight-enough.. but it's the way I do it.

Greg, A couple of questions; does your fuel pick-up line have an internal spring? Some people feel that it's important to have it in place. Have you tried installing a fuel-tubing seal over the needle-shaft where it enters the back-plate? You could have a fuel-draw issue (an air-leak?) that doesn't present itself until the level in the tank drops a bit.

Thanks for the reset tool tips. I did what you said and used a couple blasts of throttle body cleaner to blow oil and gum out of the ball socket before resetting. I read the play should be .001" to.003". Tough to measure but I would venture to guess if your rod is not falling with gravity whilst being held horizontal, the joint has no play and is too tight.

I was very careful and patient while tapping. I use a recoil-less hammer which helps me feel what's going on at the business end.

Yes I am running a spring in my line and yes, I actually did install the tube and washer in place of the NV spring. Learned that here Very Happy

More testing needs to be done.
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Re: Golden Bee Troubles

Post  Sig Skyray on Mon Jun 15, 2015 3:28 pm

Ken Cook wrote:Have you tried a stock glow plug vs the Glo-Bee? There were a couple different versions of the Glo Bee, sport and racing and one more type. Appearance wise on the outside they look the same, but the combustion chamber is different. Yours appear to be a sport if memory serves me correctly. What nitro fuel are you using? I would certainly try and bump it up for a test if you have some. 35% minimum with that plug as it sounds like the plug is cooling off. A smaller prop like a 5x3 as well.   They can be notorious for taking a dump. I like them, but they're not very reliable. Even though the plug lights up, it can give you all kinds of funny business. I would re try using a standard Cox plug. Ken

I'm running Cox 25%. Okay. I'll use a stock plug and a 5x3 for further tests. Thanks Ken.
Greg
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Re: Golden Bee Troubles

Post  Sig Skyray on Mon Jun 15, 2015 3:30 pm

Oh, and I almost have my Skyray all painted so I'll be changing my Avatar from the Sig Deweybird shown to something that matches my user name :-)

Greg
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Re: Golden Bee Troubles

Post  Sig Skyray on Tue Jun 16, 2015 7:12 pm

roddie wrote:Forgot to ask Greg.. does the engine gradually go "lean" before it quits?
No it doesn't. I guess if something were heating up, expanding and drawing air it would lean out before quitting.
I usually only test ruin on the weekends but will try to get some test results before then. Hopefully it's a non-issue.
Greg
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Re: Golden Bee Troubles

Post  Sig Skyray on Tue Jun 16, 2015 7:16 pm

getback wrote:  I hope you end play isn't like this one , All new stuff killer bee set up and I never got it to run Sad

Nope. I was worried that it was a loose front end but it's not. :-)
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