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Offline topgun

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reusing conrod bolts
« on: October 19, 2018, 12:59:29 am »
Hi Guys I,m rebuilding a 750 with Mtc rods 900 pistons  etc what are your thoughts on using the same rod bolts I am getting conflicting opinions  on this subject I want to build this motor properly as I have invested a lot into it already as you will all appreciate Cheers Tony
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Offline bear

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Re: reusing conrod bolts
« Reply #1 on: October 19, 2018, 02:43:05 am »
New bolts, they should only stretch once.

Cheers,
Brian
« Last Edit: October 19, 2018, 02:52:21 am by bear »
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Offline simon#42

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Re: reusing conrod bolts
« Reply #2 on: October 19, 2018, 09:51:34 am »
yes new bolts .
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Offline topgun

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Re: reusing conrod bolts
« Reply #3 on: October 19, 2018, 11:03:09 am »
Thanks Guys
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Offline 754

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Re: reusing conrod bolts
« Reply #4 on: October 19, 2018, 04:36:58 pm »
Are those answers geared to all rods , or aluminum in particular ?
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Offline bear

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Re: reusing conrod bolts
« Reply #5 on: October 19, 2018, 05:16:18 pm »
Quote from: 754 on October 19, 2018, 04:36:58 pm
Are those answers geared to all rods , or aluminum in particular ?

As far as I'm concerned conrod bolts are a consumable, same as clutch plates, piston rings, cush rubbers and the like.
So.. in my opinion, my answer is geard to all rods.
This isn't going to turn into an "oil thread" is it Frank? ;D
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Offline PeWe

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Re: reusing conrod bolts
« Reply #6 on: October 19, 2018, 11:33:34 pm »
Even Honda stock rods? I have a set of CB900 rods I might use if find a way to use the longer rods.
- These need new bolts and nuts?
Honda might have torqued them less than tuners do, like head nuts.
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CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline simon#42

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Re: reusing conrod bolts
« Reply #7 on: October 20, 2018, 04:28:50 am »
i would always change them , there are places where you can save a bit of money and there are places where the consequences of a failed component far out weighs the price of a new one .
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Offline bwaller

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Re: reusing conrod bolts
« Reply #8 on: October 20, 2018, 05:21:57 am »
Carrillo told me years ago the 1/4" Carr bolts are good for an infinite number of "torque sequences".

I agree OEM rod bolts are consumables and it makes me nervous what Carrillo told me. They talked me out of it last time I asked, However I think I'll push the issue this time. I'm certain they'll gladly sell me new bolts!  ;D
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Offline MRieck

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Re: reusing conrod bolts
« Reply #9 on: October 20, 2018, 08:01:39 am »
Quote from: bwaller on October 20, 2018, 05:21:57 am
Carrillo told me years ago the 1/4" Carr bolts are good for an infinite number of "torque sequences".

I agree OEM rod bolts are consumables and it makes me nervous what Carrillo told me. They talked me out of it last time I asked, However I think I'll push the issue this time. I'm certain they'll gladly sell me new bolts!  ;D
Yes...the SPS bolt can be reused as long as they are not over torqued (overstretched). For what they cost they should be reusable.
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Offline bear

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Re: reusing conrod bolts
« Reply #10 on: October 20, 2018, 08:06:59 am »
Quote from: PeWe on October 19, 2018, 11:33:34 pm
Even Honda stock rods? I have a set of CB900 rods I might use if find a way to use the longer rods.
- These need new bolts and nuts?
Honda might have torqued them less than tuners do, like head nuts.

I wouldn't use the M3 rods Peewee. Check to make sure you have the upgraded M4's.

Cheers,
Brian
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Offline PeWe

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Re: reusing conrod bolts
« Reply #11 on: October 20, 2018, 10:45:33 am »
Quote from: bear on October 20, 2018, 08:06:59 am
Quote from: PeWe on October 19, 2018, 11:33:34 pm
Even Honda stock rods? I have a set of CB900 rods I might use if find a way to use the longer rods.
- These need new bolts and nuts?
Honda might have torqued them less than tuners do, like head nuts.

I wouldn't use the M3 rods Peewee. Check to make sure you have the upgraded M4's.

Cheers,
Brian
M3 rods.... Is that CB900 dohc 79-82?
M4 later?
I heard the CB900 rods are a little bit stronger than CB750 stock.
CB750 Stock with new F2 bolts might be OK for 836-900cc anyway. Around 80whp
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CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline 754

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Re: reusing conrod bolts
« Reply #12 on: October 20, 2018, 12:19:23 pm »
 How about Goldenrod bolts ?
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Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline MRieck

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Re: reusing conrod bolts
« Reply #13 on: October 20, 2018, 08:40:14 pm »
Quote from: 754 on October 20, 2018, 12:19:23 pm
How about Goldenrod bolts ?
Some used SPS bolts...I know that for a fact.
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Offline RAFster122s

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Re: reusing conrod bolts
« Reply #14 on: October 21, 2018, 01:55:37 am »
What is an SPS bolt and how do you identify it as being one?  ..no, I  didn't google it.
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Offline Don R

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Re: reusing conrod bolts
« Reply #15 on: October 21, 2018, 11:43:20 am »
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