- Posts: 182
- Thank you received: 5
Cracked block near chain tensioner - KZ750 L3
- staniel
- Topic Author
- Offline
- User
One, the threads for the top bolt are stripped (this explains the leak I had on my 3k mile ride). The bolt spins in the hole and even wiggles some.
Then I found this:
A crack in my block across the tensioner's mounting surface.
I could use a recommendation on what to do. I love this bike and have spent a good deal of time and money on it, including having the cylinders honed, so if the answer is to cut my losses junk it, please break the news softly.
I was thinking maybe I could take the engine to a shop and have them grind out the crack and weld it back, then re-tap the threads while they're at it, but that sounds expensive.
1983 KZ750 L3 with 4-1 Kerker pipe and pods
1983 KZ750 L3 parts bike
Please Log in or Create an account to join the conversation.
- 550A2
- Offline
- User
- keep the shiny side up
- Posts: 428
- Thank you received: 1
Id bet a good weld job would work, and the only other option is new juggs.
good luck on getting it fixed man
82 Honda ATC 200-sold
82 Yamaha Virago 920-sold
82 Yamaha YZ250j-kept
80 Suzuki GS 550-sold
82 Kawasaki KZ550 A2-ride all the time
79 Kawasaki KZ650 C-sold
73 Kawasaki Z1 900E-paid $200, sold $6000
86 Yamaha Radian YX600-new project
Please Log in or Create an account to join the conversation.
- turboguzzi
- Offline
- User
- Posts: 837
- Thank you received: 72
wouldnt be hard to weld but add to the cost fly cutting the block top surface too. to do a good job youll want to weld the top of the crack too and you'll have to take a light cut to make it straight,
look at the bright side, you'll have higher compression now
are you on stock pistons? if you mange to find an ebay stock sized block in good condition and do a simple swap i think it'll be cheaper than welding and fly cutting.
what's a bit worrying is why this happened in the first place, would check that after taking it appart, quite odd.
TG
Please Log in or Create an account to join the conversation.
- larrycavan
- Visitor
Or you could stress relieve it and JB Weld it.
Please Log in or Create an account to join the conversation.
- P21
- Offline
- User
- Posts: 471
- Thank you received: 34
Kawasaki KZ 1000 Police (2002) P21
Please Log in or Create an account to join the conversation.
- TerryK
- Offline
- User
- Posts: 614
- Thank you received: 3
1977 KZ1000
GSXR swingarm and rear brake
WM6 rear Akront rim
Wiseco 1075c pistons
33 smoothbores
stage 3 Web Cams
Head porting
Dyna S ignition
Lockhart oil cooler
Wiseco header
1980 Z1R drag bike
1200cc
38 Flatslides, .
500' cams
7" slick
Dyan 4000 SP ignition
etc
Ontario, Canada
Please Log in or Create an account to join the conversation.
- Patton
- Offline
- KZr Legend
- Posts: 18640
- Thank you received: 2098
1973 Z1
KZ900 LTD
Please Log in or Create an account to join the conversation.
- TerryK
- Offline
- User
- Posts: 614
- Thank you received: 3
Is the long white line an extension of the crack?
That's what I was thinking. And it appears to be fresh. Theoretically that whole chunk of aluminum could break off.
1977 KZ1000
GSXR swingarm and rear brake
WM6 rear Akront rim
Wiseco 1075c pistons
33 smoothbores
stage 3 Web Cams
Head porting
Dyna S ignition
Lockhart oil cooler
Wiseco header
1980 Z1R drag bike
1200cc
38 Flatslides, .
500' cams
7" slick
Dyan 4000 SP ignition
etc
Ontario, Canada
Please Log in or Create an account to join the conversation.
- staniel
- Topic Author
- Offline
- User
- Posts: 182
- Thank you received: 5
Replacing the block is.. probably possible. I just got the sleeves honed and matched to my rings and did a great job wearing them in. It'd be a shame to waste that money and work. How easy would it be to swap those into a new block?
As for the cause: the only thing I can think of that's odd in there is I used two new bolts in tightening the head on and these bolts come straight through to that point. I bought stainless steel ones and ground them down to size. I tightened them per the torque schedule in the Clymer manual and in the specified order. There is a slight chance that I popped the nuts loose and not the bolts with the valve cover on. I doubt I was that stupid but it's possible.
It's pretty clear now that I can't have this welded and fixed in-frame which was my lingering hope.
1983 KZ750 L3 with 4-1 Kerker pipe and pods
1983 KZ750 L3 parts bike
Please Log in or Create an account to join the conversation.
- M357.5
- Offline
- User
- Kwakas N' lots of em'
- Posts: 341
- Thank you received: 10
I've got a block here, if you need it let me know....
83 KZ750L X2 + goodies = Project
84 KZ750L the mini ELR replica replica lol
84 ZX750E Turbo modded n' FAAAAASSSSSSTTTTT
85 GPz900r GREEN N' MEAN
Please Log in or Create an account to join the conversation.
- hardr0ck68
- Offline
- User
- Who put the what in the where?
- Posts: 804
- Thank you received: 3
Do the same with your block but make sure to number the sleeves so you can have them installed in the right hole! As far as I know the sleeves do need to be pressed back into place with a hydraulic press... but having a shop or buddy do that will be alot cheaper than the welding and resurfacing of the old block.
1977 kz650 c1
bought it because I was told it would never run again...I like to prove people wrong.
Please Log in or Create an account to join the conversation.
- kawsakiman
- Offline
- User
- Posts: 1254
- Thank you received: 6
looks to mee like there was a little oil in the hole when you tightened it.
compressing the oil will crack it as well.
someday i will be able to afford my kz habit.
Please Log in or Create an account to join the conversation.