Calling all the big block boys

I have purchased a mk11 124 link cam chain.also purchased mk11 32 tooth cam gears. I have a 76kz900. I am using a mk11 crank. Mtc big block. Stock head.when I tighten the cam tower there is NO slack left in the chain. I have to back the bolts out of the tower 1/8” to relax the chain even a bit.i do not have the chain tentioner installed.i can turn the motor over freely by hand when the tower is backed off.i only have 1 ringless piston, and light springs on 1 set of valves installed to degree the cams.

the block is about 3.53", bace gasket .020", head gasket .048". the pivoting tensioner idler can swing all the way back without interfearance with the block.

.i see a spec in the kawi manual for chain stetch. it says a new chain measures 155.5mm over 20 pins.my old kz chain measures 155.5mm.over 20 pins. the new mk11 chain measures 154mm.over 20 pins. so over 124 links the mk11 is 6 mm's shorter. i'm not sure this is enough to fix this issue. 6mm or 1/4" is just under 1/2 a link.

i just looked at the old sprockets and the new mk11's are about 3/16" larger in diameter x 2 sprockets and the mk11 crank has 1 more pin.

now the mk11 chain is only 2pins longer ,wich measure only about 9/16" -less the 1/4" the chain seems to be short. that means the new chain is only 5/16"longer than the old kz. 5/16" is not enough to make up for the 3 larger sprockets.right. even 9/16" doesnt seem like enough. what do u think?

Am I missing something?

are you sure you have the right chain?:ohmy:

Tsubaki BS05MH 124 link from APE. suposed to be?

i show an ek219H 124 link from z1,link # is the same could the links be shorter?next question,did you check to make sure the chain wasnt balled up under the crank gear?ive been up since early this morning my brain is melting down so its hurts to try and do math right now,ill check back in the morning when im awake to think a little!:laugh: unless Jay shows up before then with one of his short but to the point answers first!:laugh:

I woundered if i had a shorter kz650 tower? my tower measures 4.5mm from the bace(without pillow blocks) to the bottom of the sprockets tooth groove.
can someone please measure a stock kz900 tower and let me know if mine is a std kz900 tower?

Can someone measure a mk11 chain across 10 side plates, and tell me there length? i think i may be 1 link short on length ,even though i have 124 links.
THANKS.

lets just assume for a minute that the chain is just a tad short. what if i use 1/8" spacers bellow the cam tower. the lobe center on the exht would remain the same but the lobe center on the intake would change. So i could re degree the cam to correct. this would allow me to run the motor until the chain stretched, then I could remove the shim and re degree.
What do u think?

How long does it take for a chain to stretch?

what happens if u run a chain too tight?

Put a paint mark on the chain, count the pins???
How far are the pistons in the hole?
Has the head bin milled?
Did you install a cam chain crank guide? They bind some times.
I have dun this before I hate to admit it.
Do you have two of the top/bottom plats stuck together and installed on the bottom of the tower?
Just my first thoughts.

FastKaw1 wrote:

Put a paint mark on the chain, count the pins???
did that 3 times allready=124
How far are the pistons in the hole?
? what do u mean? i have only 1 piston installed, ringless for mock up with cams.i can turn the motor over easily with my hand, hand on the crank.after tightening the tower it is harder but will turn by hand. there is 0 slack in the chain though.
Has the head been milled?
not sure ,but if it were ,it would help, not hurt.it would bring the tower closer to the crank.
Did you install a cam chain crank guide? They bind some times.the guide was new last year but i had a stock block.u mean the L shaped 1 right?
I have dun this before I hate to admit it.
Do you have two of the top/bottom plats stuck together and installed on the bottom of the tower?
Just my first thoughts.

Piston in the hole.......
Is the top of the piston level with the top of the sleve, or is down in the block?

Cam chain crank guide.
Is C shaped nylon guide. go's under the center of the crank and keeps the
chain from slipping a tooth on the crank

i dont have a cam chian guide under the main cap.
the piston is below the deck slightly.

Ok, i made up a .065" spacer to put in the cam tower . i now have just enough movement in the rear roller to clear the back of the block and the APE tentioner has a couple turns of threads before contact.The motor now turns freely by hand untill i tighten the chain tentioner.

i will now redegree the cams ,Tear down, and move forward.

I'm still open to ideas.Thanks.

my book is showing 155.48-155.71mm over the 20 pins.i would give the tech guys at APE a call before you start making things fit the chain if its too short which could cause other reliability issues.if it is actually 2 full links in length shorter than your origional chain which was still within service limit with same number of pins it sounds to me like a manufacturing or packaging issue.since its the same overall length as the small pin 15T crank style timing chain but has 2 extra links im seriously leaning towards wrong part and would not run it untill i talked to APE

I have been in e-mail contact with him and also posting on this at dragbike.com along with Don Tanklage. It is a mystery. I have seen this twice before. Once Tsubaki had mispackaged a chain. I suggested Mark count the pins and he stated he did it several times and it is 124 which is correct.

The other case, the pivoting tensioner assy wouldn't swing back far enough, it was hitting the block. He checked his and it is not doing that.

There is something wrong here. Do not put extra spacers under the tower and start the engine.

I would start with putting paint on one pin, and counting one more time.

Jay

I think the MK II chain has two extra links. I used a MK II chain when I rebuilt my shafty and there was definitely normal slack until the chain was tensioned. I suggest you do as Plummen says and check to ensure that the chain isn't balled up on the front crank sprocket where it normally is.