crankshaft rod diisaster

ok, i have a problem.
i start to hear a knocking sound...i was thinking it was pod, but today it become louder , then i did a compression test.
150 psi in all4 cylinders engine cold,
the i look for problem in the shims/bucket and valves.... all ok.

i decided to start the teardown of the kz550 and what i found it's creepy. the first rod have a 5 cm freeplay , one rod bolt is missing...
i'm afraid of what i can find into the engine later..
what should i do?

Very lucky you haven't bent any valves and the damage should be confined to the crank.
Best scenario is you get away with new shells and rod bolts but life is rarely that good.
You will need to inspect the crank journal to see if it's scrap.
Specialist measurement tools are needed - micrometer , plastigauge etc which, by the questions you are asking, indicate that you may need to seek more professional hands on assistance.

i mean,.. if im not wrong i can't just replace the entire crank with rods from a good used one, and then just just change the bearings with new parts.
if i remember i should buy marked bearings.
i need some info.
later i will split the cases to see what happened..i will post pic.

shamal wrote: i mean,.. if im not wrong i can't just replace the entire crank with rods from a good used one.

Yes! you can.
If the used crank/rod assembly is within limits all you need to do is fit new MAINS by cross referencing the numbers and letters on the crank webs and crank case to work out what colour shells you need.

ok, thank your help is priceless. this afternoon i'm going to split the case, and then i will post pic so you can give me some advices!

ok, its a disaster.
the number 1 connecting rod had a loose nut. i can't explain how this ca happen.
the loose nut let the bolt fall from his seat., so the bearing of the rod is destroyed.
while moving, the bolt of the rod hit the cylinder, and cracked it.

i think the best solution is a new set of used cylinder from ebay. honing from the engine serfacing guy and go.

about the crank, it appear to me ok. but since i need a rod and the bearing surface on the crank for the broken rod is worn, i think i can buy a used crankshaft from ebay too.
i found crank from gpz 550 D and GPZ 550 B

on CMSNL.com i see the crankshaft code is always the same..is this true? can fit in my gpz 550 H ?

about markings on my crank, i see nothing else that the yellow mark near the number two rod. (see pic)

advices?

help mates..

Crank is bad. I repair cranks like yours all the time.
Get digital vernier caliper and cut off rear horns, maybe it will measure journal. I see it is bad by light reflection.

i think to buy a used good crankshaft with rods still fitted and crank journal..
are the cranks for 550 B 550 D 550 H and 550 A the same spare part number?

Need better pics of the crank and bearings. The stripe down the center is normal.
Steve

shamal wrote: i think to buy a used good crankshaft with rods still fitted and crank journal..
are the cranks for 550 B 550 D 550 H and 550 A the same spare part number?

There's an ad here for two parts bikes. Talk to him.
Steve

swest wrote:

shamal wrote: i think to buy a used good crankshaft with rods still fitted and crank journal..
are the cranks for 550 B 550 D 550 H and 550 A the same spare part number?

There's an ad here for two parts bikes. Talk to him.
Steve

sorry, i don't understand :blush:

kzrider.com/forum/23-for-sale/602473-parts-83-84-kz550