P500 Serious Major Screw-up during valve check!!!

FuzzyGrub

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Doing maintenance on my P500. With nearly 5500 miles on her, thought I would at least check what the valve gaps were. They have never been checked from new. My idle has been slightly erratic and thought that might have been a possible cause/contributer. Instead of using a straw to find TDC, was using a 3/8" diameter wooden dowel. With a small bump in 5th gear, I heard the dowel rod crack. A very sickening noise!!! It broke off with a piece in the spark plug threads. It is about 2-3" long. Many attempts to fish it out, but couldn't get it oriented right. It has now rolled out of view! :(

Looking at the service manual I can't tell for sure if I could get the head cover off and then the head, without removing the engine. To me, the chassis would be in the way of getting the head off. Even if it clears, it is not going to be a "fun" job. Has anyone done or tried to do this while in the chassis?

I am going to start to look at all the work it is going take to remove the engine. :(
 
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If you look in the front of the cylinder head/valves section there will be a paragraph about whether that particular part can serviced in the frame or not.

I've never done any top end engine repair on a 500 ao I can't say for sure.
 
FuzzyGrub

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I couldn't find anything in section 10 Cylinder head/Valve, but in section 11 Cylinder/Piston, it says that both can be serviced with the engine in the frme. So, the head should be doable. A little positive news.

Guess what the first step is? Rotate engine to TDC on the compression stroke! Don't think it is going to rotate past TDC, just don't know what stroke it is on.
 
DRZRon1

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rule #7, no good deed goes unpunished - damn.......

have to ask, have u tried one of those small claw flexible material grabbers, they have saved my butt many times but have to admit not down a spark plug hole


any chance to wiggle it back in view an stab it with a pin on the end of something and try fishing it back out
 
Red500

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Man that sucks. I don't know if it would help but I think I would try looking at it with a bore scope to see if you can find it in the cylinder and then try fishing it out. Good luck with it.
 
FuzzyGrub

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I had tried to use a coat hanger with a small "L" bend that could fit through the spark plug hole, to sweep into view, but no luck. I use to have one of those claws but can't find it when you need it.

Thx bore scope idea. I do have one and was able to see it before the battery died. It is recharging now. If I could somehow fish it out, that would save me an extreme amount of work. My fingers and toes are crossed.
 
DG Rider

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The little claw might get it. That's what I'd try.

If that fails and you have compressed air, try and see if you can rotate enough to get the intake or exhaust valves open and blow air in through them. Really depends on where you were when it broke. If you were close to tdc, you should be able to rotate it backwards (yes, I know) and get the intake open. It's amazing how a blast of air can tumble things into coming out.

Also: there is a cover with three bolts on the rear of the engine. Under it is a nice bolt on the crank so you can rotate in a nice, controlled manner. The whole "rotate it in gear" thing is very sloppy for this sort of thing.
 
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906UP

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You can do the head/cyl in the vehicle, its not hard but time consuming. You need to unbolt the entire seat frame, that will give you room to remove the head
 
906UP

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This is what it will look like with the seat frame out. I had to do this on a neighbors buggy after he swamped it, have to remove the seat frame to get the exhaust out also
 
FuzzyGrub

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OK, here is where I'm at:

Prior to seeing the last few sets of posts, I tried to see if I could turn it over via the 5th gear approach. Ie was going to start the head cover removal procedure. It was able too, and did it it numerous times. The bore scope revealed just small pieces. So grounded the high tension lead and turned it over with key for a numer of short bursts. Pieces flew out. Bore scope showed only a few pieces. Did it a few more times.

Then the very risky decission to try to start it. It did start, but only ran it for 30 seconds. Let it sit, and did it a few more times. I'm going to do this a few more times with inspections between. The bore scope is not able to manuver to every knick and cranny. Maybe not the smartest thing I've done, but right now it is looking promising.

PS; If good, not going forward with the valve clearance check, today! ;)
 
Smitty335

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OK, here is where I'm at:

Prior to seeing the last few sets of posts, I tried to see if I could turn it over via the 5th gear approach. Ie was going to start the head cover removal procedure. It was able too, and did it it numerous times. The bore scope revealed just small pieces. So grounded the high tension lead and turned it over with key for a numer of short bursts. Pieces flew out. Bore scope showed only a few pieces. Did it a few more times.

Then the very risky decission to try to start it. It did start, but only ran it for 30 seconds. Let it sit, and did it a few more times. I'm going to do this a few more times with inspections between. The bore scope is not able to manuver to every knick and cranny. Maybe not the smartest thing I've done, but right now it is looking promising.

PS; If good, not going forward with the valve clearance check, today! ;)
Do you have a nest of termites some where?
 
FuzzyGrub

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The dowl rod is soft pine, and just the cycling in 5th gear broke it into tiny pieces. That 1st revolution was as slow as I could move it, such that if it did jam, wouldn't have been enough force to bend rod or break piston. Before starting it, could not find any pieces left big enough for a gripper. Did it a few more times to see if it was just out of reach/sight, but still didn't see it.

Yes, very risky, and don't recommend it for others. If I did not have the bore scope, would be dis-assembling by now. As of now, not seeing any trace of pieces. A few morre cycles, then will start reving it vs idle. As it is, the idle sounds normal.

If something bad happens, I will post it.
 
DG Rider

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OK, here is where I'm at:

Prior to seeing the last few sets of posts, I tried to see if I could turn it over via the 5th gear approach. Ie was going to start the head cover removal procedure. It was able too, and did it it numerous times. The bore scope revealed just small pieces. So grounded the high tension lead and turned it over with key for a numer of short bursts. Pieces flew out. Bore scope showed only a few pieces. Did it a few more times.

Then the very risky decission to try to start it. It did start, but only ran it for 30 seconds. Let it sit, and did it a few more times. I'm going to do this a few more times with inspections between. The bore scope is not able to manuver to every knick and cranny. Maybe not the smartest thing I've done, but right now it is looking promising.

PS; If good, not going forward with the valve clearance check, today! ;)
Meh...if there were truly only small pieces left, I don't know that I wouldn't have done the same thing with the plug out.
 
FuzzyGrub

FuzzyGrub

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At that point it seems you could use a piece of tubing small enough to go thru the plug hole -hook it up to your shop vac and clean it out...
I didn't think of that and probably could have come up with some sort of reducer. It probably would have been "safer" than the turning engine over and blowing it out the spark plug hole. At some point, you have to still make the decision if you think you got most/all of it. Choice is then to start it or tear it down.

If I had waited for the responses before going further with the 5th gear, the borescope and claw might have worked.

This won't happen again.
 
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