Gears jumped up a slot?

[jetmechmarty]

I broke one off in my XS650. That's why I'm in the don't grind it camp.

[trbig]

I knew you'd broke one off, but this is the first time I've heard of all three. I wonder if it's something that just happened one at a time over a period of time. I just can't see all three breaking at once.

[BA80]

Hey Marshall, http://www.xs11.com/forum/showthread...180#post422180

[Bigfoot]

I can't see this being the result of grinding. I don't remember the location of that circlip but if that failed first, could this be the result of the bike trying to go into 2 gears at the same time?

Cbug, I saw in the other thread that greg posted that you were looking for an oil pan as well. How did you break an oil pan?

[TopCatGr58]

All I can say is WOW! But this does make me wonder how much was ground off, but I think more importantly is down at the base of the dog/grinding zone, did you leave a sharp corner, or more rounded?

I use dremel stones, and I always end up leaving a rounded corner down at the main gear to dog interface/joint. If it is ground/cut with a resultant SHARP corner (at the dog to main gear point, not the END of the dog), I would think that would lend itself to start a stress fracture easier. But I'm no engineer or metalurgist....I know Marty is a jet engine mechanic, and especially with turbine engines I've watched the discovery/learning channel showing how the blades of the turbines are made, inspected, etc.! So I can understand Marty's affinity for putting in NEW stuff vs. trying to repair/mod the old stuff/parts! Just some thoughts!

T.C.

[CatatonicBug]

That snap ring was just the one off the oil pump idle gear. It wasn't the cause of any of this. I know I ground those dogs, and would have used a cut-off wheel, so the point where it met the gear face may have been more square than round. Not sure if that was part of the problem or not. I went over to meet DCSmith today, and picked up the extra motor, so now I can take it apart and harvest the parts I need.

The oil pan issue was my own stupidity. For some reason, 4 of the oil pan bolts got stuck, and I had to drill them out. I got 3 of them drilled, and forgot the one on the left side, closest to the frame... I ended up cracking the pan because I couldn't understand why the pan wasn't letting go, so I pried it away from the case with a screwdriver until I heard a "pop"!

My crossover pipe also broke inside the clamp (rusted at the joint), so I had Napa order me some 1.5"OD pipe ($0.28/ft) so I can replace that section too.

Just sucks, because the weather has been so great here! I wanna be riding, not wrenching!

[Rasputin]

If it turns out your donor engine is not what you need let me know. I have those gears and I think if I look hard enough an oil pan or two may be available. One is for sure but it is still in a bike so would take a bit o doing.

[CatatonicBug]

I got the parts out of the donor engine, and the countershaft gears were incredibly clean! They could have passed for NOS! Rather than use my ground gears, I simply swapped the washer and put the entire countershaft into my bike. After 2 days of riding, it runs great! I guess this will be my test as to whether the washer swap is sufficient to prevent the gears from rounding over.

The donor engine had the internals for the kick-starter in it, and I removed them, since they seemed to get in the way when I was removing the countershaft. I was tempted to just add them to my MNS, but decided against it. I don't have the pieces that go under the cover, next to the clutch basket anyway, and the MNS isn't supposed to have a kick-start. I also threw a K&N air filter in there while I was at it. My yellow foam one started to get holes in it.

I need to locate an exhaust clamp, since the clamp on the #3 header snapped, but the gaskets are all so smashed and corroded that the seal seems to be fine for now. I'm afraid to replace them though, for fear that the headers will come apart just like the crossover pipe did. I had to cut off a 3" section of the crossover pipe and weld on a new piece of pipe when the short piece that was inside the clamp ripped off the end.

[senrak]

I guess the biggest question remains. Why did this happen? Scary!

[kevxs]

I guess the biggest question remains. Why did this happen? Scary!

+1 on that. anyone have any ideas?

[trbig]

Only thing I can think of is maybe took too much meat off of at least one of the dogs during grinding. I doubt they all broke at once.. probably one at a time.

[DGXSER]

One can only guess. My guess is Todd is correct. Had to be something about the way the gears were ground. Angle of the grind, or depth of the grind.

I'm not trying to condemn bug or how he did his work, just suggesting that it is important to check the three dogs contact together, the grind is not overly steep, etc.

Might be he had something else go wrong that caused it, a bearing sieze etc. These are just the most likely things.

[trbig]

One can only guess. My guess is Todd is correct. Had to be something about the way the gears were ground. Angle of the grind, or depth of the grind.

I'm not trying to condemn bug or how he did his work, just suggesting that it is important to check the three dogs contact together, the grind is not overly steep, etc.

Might be he had something else go wrong that caused it, a bearing sieze etc. These are just the most likely things.

Agreed... I wasn't implying that he did shoddy work. Who knows how much is too much? Since these seem to mesh together pretty quickly after a grind, my guess is that one of them probably broke soon after re-installation when they weren't quite hitting at the exact time, putting all the strain on just one dog. Then the other two held on as long as they could... went down to one tooth at some point, then as these shift hard into first, it finally got the last one. With the gear running with less than 3 dogs, it would have been off balance just a bit and might have had something to do with vibrating just enough to kick that circlip off the end of the shift fork shaft.

All just speculation and guessing though. Marty.. did you only realize you broke a dog after finding it in the pan, or could you feel something was wrong?

[jetmechmarty]

I found the dog in the pan. The XS650 gear train appears to be just as stout as the XS1100, so I don't expect failure is as likely. I'm still turning on two dogs.

[jetmechmarty]

My smart phone double posted. I guess it ain't so smart.