Update To Rocker Failure

Husadawg · Apr 13, 2005

Finally got a chance to pull the rocker cover last night to inspect the failure. What I found was a bit of a surprise. The rockers are in excellent condition with no detectable wear. The noise that I assumed was one or more failed rollers turns out to be a water pump impeller that I took out in several pieces. I replaced this part with a new one when I rebuilt the rockers about 100hrs back.

Anyone else seen something like this? It's almost as if something jammed the impeller and it sheared off the locking pin on the cam. Of course that's just an assumption based on some very small pieces available for inspection. I am glad I shut the engine down as soon as I heard the noise. It would obviously have overheated very quickly.

One other question, what is the expected life of the cam chain and sprocket?

Thanks,
Husadawg 8)

dsducati · Apr 13, 2005

Assuming the bike is an old motor with the impeller on the cam. Isn't the impeller plastic or possibly aluminum if an aftermarket impeller? Not sure how they would shear the steel drive pin. Have had the plastic impellers split before and the drive pin would be laying in the bottom of the impeller housing unhurt.
Dan

Husadawg · Apr 13, 2005

It's a 00 model year with a plastic impeller. Sorry I didn't explain it very clearly but the steel pin didn't shear. It looks as if the plastic impeller jammed for some reasons and then the cam with the steel pin sticking out simply ripped the impeller apart. Again, that's just speculation.

berger · Apr 13, 2005

Have you checked the cam bearings and camshaft end play?.

Husadawg · Apr 13, 2005

Haven't checked them yet but the bearings were new 100 hrs back. Do you happen to know the end play spec?

70marlin · Apr 13, 2005

Husadawg said:
Finally got a chance to pull the rocker cover last night to inspect the failure. What I found was a bit of a surprise. The rockers are in excellent condition with no detectable wear. The noise that I assumed was one or more failed rollers turns out to be a water pump impeller that I took out in several pieces. I replaced this part with a new one when I rebuilt the rockers about 100hrs back.

Anyone else seen something like this? It's almost as if something jammed the impeller and it sheared off the locking pin on the cam. Of course that's just an assumption based on some very small pieces available for inspection. I am glad I shut the engine down as soon as I heard the noise. It would obviously have overheated very quickly.

One other question, what is the expected life of the cam chain and sprocket?

Thanks,
Husadawg 8)

Been there Done That, they make a helluva noise when they go! my circlip came loose. a very cheap repair though.

Husadawg · Apr 13, 2005

The circlip is still in place on the end of the camshaft. The impeller is gone (in pieces) but the circlip is still there.

husadawg 8)

berger · Apr 13, 2005

I dont have the end play specs, but if I had the rocker cover off at 100 hours, I would be replacing the cam bearings. The bearings are inexpensive and a good insurance policy.

dsducati · Apr 13, 2005

Sounds like my old problem with the cheesy plastic impeller splitting, but mine didn't make a lot of racket. Plastic impeller is quite soft. You may have a cam bearing that has gone south flopping the impeller into the casting
Dan

Husadawg · Apr 13, 2005

I haven't had a chance to take the cam out yet but as the cam bearings were new only about 100 hrs ago and are quite substantial, I will be surprised if they have worn enough to cause said problem. Nevertheless, I will post my findings.

I do plan to go ahead a replace bearings, sprocket and chain along with a new impeller. Just not sure I've identified the failure mechanism yet.

Thanks for all of the thoughts and suggestions guys, much appreciated.

husadawg 8)

nsman · Apr 13, 2005

Husadawg,
Any chance you are using a coolant without any antifreeze ability?It takes very little time below freezing to create a piece of ice that can destroy your water impeller......nsman

nsman · Apr 13, 2005

I noticed that the water pump impeller on my o5 fe550e runs close enough to the cover that it is leaving wear marks on the cover.There is a certain amount of freeplay between the impeller and the circlip.The parts manual shows no shim between the circlip and the impeller to take up this play....my question has anyone shimmed this play or should there be no play between the clip and impeller?.....nsman

Husadawg · Apr 13, 2005

Great question and thought nsman. I run a 50:50 mix of antifreeze, not so much because of the temperature (we don't get that cold here is Arizona) but primarily to prevent corrossion.

husadawg 8)

BOSS · Apr 19, 2005

Husadawg said:
I haven't had a chance to take the cam out yet but as the cam bearings were new only about 100 hrs ago and are quite substantial, I will be surprised if they have worn enough to cause said problem. Nevertheless, I will post my findings.

I was woundering your milage,when you say new only 100hrs ago?

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Update To Rocker Failure

Husadawg

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70marlin

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