Author Topic: To bore or not to bore....  (Read 680 times)

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Offline Paul Lowe

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To bore or not to bore....
« on: April 15, 2014, 06:28:29 pm »
Hi all,  I have a series of questions for my learned friends who share the Honda sickness...:-)

My first post relates to cylinder boring.

I have a couple of choices and don't know which is best for my cb750 K1

1) have my existing barrel which is currently at 0.5 taken out to 0.75 and buy new pistons and rings.
Approx cost all up $4-500

2) have is bored out to 836cc and buy an eBay kit ($150) with pistons, rings pins and gasket.
Approx cost all up $5-600

3) buy a K0 barrel and pistons which appear to be original and low miles and just hone and buy new rings.
Approx cost all up $5-600

How well does the K1 barrel handle the 836 bore and how much is removed?
I only really what a good solid reliable bike.

Thanks.
My Honda sickness deepens

CB350F 1972
CB360G 1974
CB750 K1 1971
CT90 K0 1968
C102 1963
C50 1968
C70 1972
C90 1974
CL90 1968

1/2HP electric bike home made...

Offline Nick0

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Re: To bore or not to bore....
« Reply #1 on: April 15, 2014, 07:20:00 pm »
Bore


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Offline Paul Lowe

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Re: To bore or not to bore....
« Reply #2 on: April 15, 2014, 07:32:21 pm »
Big?
My Honda sickness deepens

CB350F 1972
CB360G 1974
CB750 K1 1971
CT90 K0 1968
C102 1963
C50 1968
C70 1972
C90 1974
CL90 1968

1/2HP electric bike home made...

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: To bore or not to bore....
« Reply #3 on: April 15, 2014, 07:55:25 pm »
Go big(ger).

836 = mid size = +4mm

As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Paul Lowe

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Re: To bore or not to bore....
« Reply #4 on: April 15, 2014, 07:59:07 pm »
Still leaves enough meat?  Heating problems?
My Honda sickness deepens

CB350F 1972
CB360G 1974
CB750 K1 1971
CT90 K0 1968
C102 1963
C50 1968
C70 1972
C90 1974
CL90 1968

1/2HP electric bike home made...

Offline Paul Lowe

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  • Posts: 174
  • If you like then it is good...
Re: To bore or not to bore....
« Reply #5 on: April 15, 2014, 08:06:35 pm »
This kit

 http://bit.ly/P4jfGR

Seems cheap? Not looking to do a lot of miles. Anyone used it?
My Honda sickness deepens

CB350F 1972
CB360G 1974
CB750 K1 1971
CT90 K0 1968
C102 1963
C50 1968
C70 1972
C90 1974
CL90 1968

1/2HP electric bike home made...

Offline PeWe

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  • Bike almost back to the 70's 2015
Re: To bore or not to bore....
« Reply #6 on: April 15, 2014, 10:59:03 pm »
You have not used the search button... Search  cruzinimage and you will find several threads.
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