Topic: Crankshaft Problems CB750

[Jens77]

Bad News...i checked again...23,13 is in the base.
You can see where the crankshaft worked, its only 22,75
So what to do now?
Its the service limit...any experience?

[Tracksnblades1]

Excellent pictures... You know what they say about a picture's worth.

If I read 754 last post, I think someone My have already tossed the old crank.

You may be looking at the old cranks wear marks. I think it is what was trying to do the welding.

Does the crank you removed have matching wear marks...?

[Jens77]

Yes...you can see it in the crankshaft, looks little like polished

[754]

It's strange.
 It does not look deep so may not be a  problem , work the high spots off.
 One thing comes to  mind.. maybe.  . Bike went down on alternator side breaking cover,  kept running pushing the crank against the thrust surface ? .

[bryanj]

If it is still in spec use it

[Jens77]

I dont know about the history of this bike.
Everything might be possible.
Some say the case is rubbish.
I am not sure, its not too deep...but on the service limit.
Hmmm...i remouved the material carefully.
Have to check crankshaft and rods.
Then i will use it again..i did not get a new on Christmas 😣
Anybody tried washer on legt and right side or other way of guiding the crankshaft?

Happy 2019

[bryanj]

DO NOT put anything on end of crank.

[Tracksnblades1]

What is your end play ( thrust ) clearance....?

[Tracksnblades1]

I finally found Honda's production min, max, and service limit in the same publication.
Hope this helps with your decision. Have a Happy New Year.....Hic-cup...Hic-cup...burp......hic-cup
Toot......🎉😎