« previous next »
Pages: [1]   Go Down

Author Topic: motor work  (Read 1874 times)

0 Members and 1 Guest are viewing this topic.

Offline Ridgeback

  • Full Member
  • *
  • Posts: 21
motor work
« on: July 15, 2012, 06:20:15 PM »
Hi.  Can anyone point me to someone in the Brisbane (Aust) area who's good with CB750 K motors please.  I need someone to regrind  the crankshaft and re-bore the cylinders.   

I don't want to take it to just anyone.  I'm looking for the best.

Thanks.
Logged

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 14,018
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Re: motor work
« Reply #1 on: July 15, 2012, 10:32:44 PM »
Quote from: Ridgeback on July 15, 2012, 06:20:15 PM
Hi.  Can anyone point me to someone in the Brisbane (Aust) area who's good with CB750 K motors please.  I need someone to regrind  the crankshaft and re-bore the cylinders.   

I don't want to take it to just anyone.  I'm looking for the best.

Thanks.

You won't be able to "regrind" these crankshafts, as the bearings only come in -.0010" size. No one makes undersize bearings. What is wrong with the existing one? It takes a major event to damage them, and another used one is normally far cheaper than machine shop work.
Logged
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline Ridgeback

  • Full Member
  • *
  • Posts: 21
Re: motor work
« Reply #2 on: July 16, 2012, 12:05:21 AM »
When I pulled the crankshaft I found 3 of the main bearings had worn through
the white metal of the bearing shells and the crankshaft is badly scored on
two journals. The big end bearing shells also show a lot of wear.
Logged

Offline nancy

  • CB750 K2'ish - SOLD!! Triumph Sprint GT2011
  • Hot Shot
  • ***
  • Posts: 672
  • No worries matey..
Re: motor work
« Reply #3 on: July 16, 2012, 12:30:18 AM »
If the journals are BADLY scored - best to ditch it and buy another, newer and lower mileage/less abused crank. Just been down this path this month. My crank is OK..but might not have been. I found one here in NZ for $250NZ...should I have needed it...but I didn't... I spent $150 on having the crank and cases mic measured and checked by a machinist. End result - crank was still inside allowable tolerances...but a close call.
No way forward for a bad crank that I know of...except wave it goodbye. Probably indicative of years of hard motoring with few oil changes.
There are plenty around on fleabay...US$50-$70 and add US$140 or so shipping. Still some in NZ - should be plenty over the ditch - wouldn't there? What about asking Terry or one of your mates there?
regards
Mark
Logged

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,279
  • ROCK & ROLL
Re: motor work
« Reply #4 on: July 16, 2012, 12:41:19 AM »
There are a few guys around Brisbane that can rebuild these old girls well, new crank shouldn't be too hard to find and will probably be a lot cheaper than trying to fix a scored one..... I may be able to help out with a crank... Where in Brisbane are you Ridgeback..?
Logged
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline Ridgeback

  • Full Member
  • *
  • Posts: 21
Re: motor work
« Reply #5 on: July 16, 2012, 01:30:41 AM »
I'm North of Brisbane, near Dayboro.
Logged

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,279
  • ROCK & ROLL
Re: motor work
« Reply #6 on: July 16, 2012, 02:00:00 AM »
I'm on the southside, Redlands. I just bought a parts bike off a guy near Greenbank that said he had a spare crank, i can ask him when i pick the bike up later this week.... I know of an old guy thats is very good with machining , he is at Mount Gravatt, works from home...
Logged
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline Ridgeback

  • Full Member
  • *
  • Posts: 21
Re: motor work
« Reply #7 on: July 16, 2012, 02:51:32 AM »
I've heard of a guy at Wishart that works from home, but I wasn't sure he works on Jap bikes.  A mate of mine got some work done on his Trident there and say's he thinks he saw a Kwaka 900 motor there.  It wouldn't be him would it?  His name was Ron.

Either way, any further info would be good thanks.

Are the cranks in K engines interchangeable.  Mine's a K3.
Logged

Offline lucky

  • Really Old Timer ...
  • *******
  • Posts: 6,717
Re: motor work
« Reply #8 on: July 16, 2012, 04:11:47 PM »
Quote from: Ridgeback on July 16, 2012, 02:51:32 AM
I've heard of a guy at Wishart that works from home, but I wasn't sure he works on Jap bikes.  A mate of mine got some work done on his Trident there and say's he thinks he saw a Kwaka 900 motor there.  It wouldn't be him would it?  His name was Ron.

Either way, any further info would be good thanks.

Are the cranks in K engines interchangeable.  Mine's a K3.

Yes, the cranks are interchangeable.
Give them a visual check though.
Logged

Offline CrankyOldGuy

  • Wish I was a
  • Hot Shot
  • ***
  • Posts: 503
Re: motor work
« Reply #9 on: July 16, 2012, 06:05:05 PM »
Ever try Japanese Motorcycle Dismantlers in NZ.  I have e-mailed back and forth with them and they were quite helpful.

Harry O.
Logged
750 K1 Original Owner

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,279
  • ROCK & ROLL
Re: motor work
« Reply #10 on: July 17, 2012, 04:44:17 AM »
Quote from: Ridgeback on July 16, 2012, 02:51:32 AM
I've heard of a guy at Wishart that works from home, but I wasn't sure he works on Jap bikes.  A mate of mine got some work done on his Trident there and say's he thinks he saw a Kwaka 900 motor there.  It wouldn't be him would it?  His name was Ron.

Either way, any further info would be good thanks.

Are the cranks in K engines interchangeable.  Mine's a K3.

Ron Russ, is his name and i have his phone number here somewhere, he works on Honda's as well, i know a couple of guys that go to him, he's very fussy and does excellent work.  I'll get a price on the crank and get back to you...
Logged
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,279
  • ROCK & ROLL
Re: motor work
« Reply #11 on: July 17, 2012, 11:38:14 PM »
Ridgeback, I can get a crank if you want one, i have to go and pick some parts up in the next few days, if you want the crank let me know because i won't be going out there again any time soon.... Check your private messages, my phone number is there..

Mick
Logged
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.
Pages: [1]   Go Up
« previous next »