Generator / Rotor Bolts - Sheared and Damaged - Page 3

gzbobber · 06-07-2014, 08:56 PM

Hi, I recently had the same thing happen with one bolt on the balancer. I retapped the hole and replaced the bolt. The bike wouldn't fire. I took the balancer off and saw the the key had sheared off smooth. Any ideas as to why this may have happened? Also posted some pics of it's life to help visualize.2 Suzuki GZ250.jpg

4 Stripped (2).jpg

10 Green glow.jpg

0209141338.jpg

0216141849.jpg

gzbobber · 06-07-2014, 09:04 PM

Water Warrior 2 · 06-08-2014, 01:37 PM

The key serves 2 purposes. One is for proper alignment of parts and Two..........it is the weakest link in the chain. It will shear off due to metal fatigue before something else lets go and causes major destruction. This is my opinion only but seems to make sense to me. The manufacturer could make everything absolutely indestructable but then you have a 250 GZ that weighs twice as much and costs a lot more too. The key is a sacrificial item to preserve the rest of the engine.
Luckily you only had to do some minor repairs rather than push home a bike with a grenaded engine. Look at the positive side of the repair. Could have been a lot worse.

clofan · 06-09-2014, 10:17 AM

I don't think I understand, which part is the key?

Water Warrior 2 · 06-09-2014, 05:02 PM

Quote:

Originally Posted by clofan

I don't think I understand, which part is the key?

This is a time when a pic is worth a thousand words. I just Googled shear keys and was amazed at the results. After 4 or 5 pages I found some suitable info pretaining to small engines. Try it yourself and see what happens. Our world could never exist without shear applications in our daily lives. Everything from small engines to bridge building or the houses we live in.

gzbobber · 06-12-2014, 04:06 PM

My key came in today, when I get home I'll be replacing and reassembling. I will document and post my installation procedure, maybe it can help someone in the future. It may also show someone what not to do, lol.

Water Warrior 2 · 06-13-2014, 01:30 AM

Oh good! I hope you can do some close up pics. I have actually never seen that part of the bike up close and personal.

gzbobber · 06-13-2014, 11:35 AM

If I'm not mistaken those three threaded holes are simply there to split the crankcase apart.

gzbobber · 06-13-2014, 11:42 AM

I definitely will get some good pics for you guys. The key they shipped me was incorrect, was an 08 not a 2000, about .045" too thick to fit in the keyway. Ordered one again should be here wednesday. Ill post some "as-is" pics today when I get home. Almost convinced myself to shave it down but im afraid it might compromise the "fail-safe" characteristics of it. Just wait on the new one. Bummer

gzbobber · 06-13-2014, 12:50 PM

Ill get more during installation.

06-07-2014, 08:56 PM	#21
gzbobber Junior Member Join Date: Jun 2014 Location: Tampa, FL Posts: 8	New to the forum Hi, I recently had the same thing happen with one bolt on the balancer. I retapped the hole and replaced the bolt. The bike wouldn't fire. I took the balancer off and saw the the key had sheared off smooth. Any ideas as to why this may have happened? Also posted some pics of it's life to help visualize.2 Suzuki GZ250.jpg 4 Stripped (2).jpg 10 Green glow.jpg 0209141338.jpg 0216141849.jpg Login or Register to Remove Ads
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06-08-2014, 01:37 PM	#23
Water Warrior 2 Senior Member Join Date: Dec 2006 Location: Squamish B.C Canada Posts: 11,409	The key serves 2 purposes. One is for proper alignment of parts and Two..........it is the weakest link in the chain. It will shear off due to metal fatigue before something else lets go and causes major destruction. This is my opinion only but seems to make sense to me. The manufacturer could make everything absolutely indestructable but then you have a 250 GZ that weighs twice as much and costs a lot more too. The key is a sacrificial item to preserve the rest of the engine. Luckily you only had to do some minor repairs rather than push home a bike with a grenaded engine. Look at the positive side of the repair. Could have been a lot worse. Login or Register to Remove Ads
	0

06-12-2014, 04:06 PM	#26
gzbobber Junior Member Join Date: Jun 2014 Location: Tampa, FL Posts: 8	Replacement parts arrived My key came in today, when I get home I'll be replacing and reassembling. I will document and post my installation procedure, maybe it can help someone in the future. It may also show someone what not to do, lol.
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06-09-2014, 10:17 AM	#24
clofan Junior Member Join Date: Mar 2014 Posts: 29	I don't think I understand, which part is the key?
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06-13-2014, 01:30 AM	#27
Water Warrior 2 Senior Member Join Date: Dec 2006 Location: Squamish B.C Canada Posts: 11,409	Oh good! I hope you can do some close up pics. I have actually never seen that part of the bike up close and personal.
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06-13-2014, 11:35 AM	#28
gzbobber Junior Member Join Date: Jun 2014 Location: Tampa, FL Posts: 8	If I'm not mistaken those three threaded holes are simply there to split the crankcase apart.
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06-13-2014, 11:42 AM	#29
gzbobber Junior Member Join Date: Jun 2014 Location: Tampa, FL Posts: 8	I definitely will get some good pics for you guys. The key they shipped me was incorrect, was an 08 not a 2000, about .045" too thick to fit in the keyway. Ordered one again should be here wednesday. Ill post some "as-is" pics today when I get home. Almost convinced myself to shave it down but im afraid it might compromise the "fail-safe" characteristics of it. Just wait on the new one. Bummer
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