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Author Topic: Where do i go from here?  (Read 368 times)

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Offline Carver

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Where do i go from here?
« on: August 17, 2014, 03:14:29 PM »
Alright so I threw a rod and broke one of my sleeves. I split the cases yesterday and found half of the lower rod, and some bearing shells, and a bent rod bolt in the lower case. Still haven't found part of the sleeve so I need to look around more down there. Do I get totally new rods? What am I assessing for damage to the actual crank?

Also It was slipping out of second gear, What am I looking for in the transmission that could cause this?

Thanks guys.
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Cb 450 dohc k4

Offline calj737

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Re: Where do i go from here?
« Reply #1 on: August 17, 2014, 04:07:19 PM »
Which bike from your signature? In both situations, I'd strongly expect a new motor would be a better investment. The trans can be rebuilt, the rods/sleeves/pistons can all be replaced. The crank, well that could require some work if banged up.

Where I'd be really concerned; if there is significant damage to bearing surfaces on the case side, that is very tricky to repair. Lots of donor motors around, Bill Benton in Atlanta has several 750s I know of. The DOHC could be a different question for finding donors as readily.

You'll also have to verify that the piston that came loose didn't also damage the head.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Carver

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Re: Where do i go from here?
« Reply #2 on: August 17, 2014, 04:43:46 PM »
It's the 750.

I already got new jugs/pistons ready to install.

The crank looks alright, but im not sure how to assess it or measure it to check.

the other 3 rods look alright but im not sure what to do about the one that broke.
Do I just get another one to replace it off ebay or is it better to just get a whole new set?

I don't see any damage to the actual cases or the inside of the engine at all.
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Offline calj737

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Re: Where do i go from here?
« Reply #3 on: August 17, 2014, 05:06:05 PM »
Might be best to have a machine shop mic the crank, and at least polish the journals. There are dissenting opinions about knife-edging and balancing, so you're on your own there.

If you can find a single rod, buy it. But, I'd give strong consideration to all new rod bolts. Bill Benton may have a rod, or a whole set at a decent price. I mention him as he is not too far away and has tremendous spare parts. He's a racer too, so what you get will be good condition even if used.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline ekpent

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Re: Where do i go from here?
« Reply #4 on: August 18, 2014, 05:00:24 AM »
Figure on splitting the cases if you want to fix the tranny then take a good look around the cases for further damage/inspection. Replacement engine may be a good option.
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