2005 Kawasaki STX-12F Engine Rebuild Question

[BigDog9721]

Hello everyone, I apologize, but this will be a long entry to my question.

I recently am rebuilding an 05 STX 12F engine from the ground up. My first time in rebuilding an engine, it's been fun, but a slow and also a learning process along the way.

Ok, I have put new pistons, rings, bored the cylinders, cleaned up some old parts and am in the critical final stage of installing the cams. My problem is, when i install the cams (watching youtube) and aligning the lower cog attached to the crankshaft, and the 2 upper cams [--intake and exhaust--] lined up on sides like the dashes in [ ], I can't seem to turn over the engine with a socket wrench to see if all is smooth in the top engine. Before i put cams in, I could turn the engine easily with not much effort, but afterward after installing the cams on the cylinder head and cover the timing chain gets tight and cams do not want to move much at all. In some instances it just sticks. Now i know better to muscle through this because I'm sure I'll bend a valve or something.

So, here are my questions...
1. Do you think the valves could be stuck and that is what's stopping the cams from turning? I did have a local machine shop do a valve job including shims.
2. Even though I have followed the service manual to the exact tooth on the timing chain, maybe the cams are 180 degrees off? (2 revolutions on crank sprocket to 1 revolution on cam)
3. When I tighten down the cam cover, there is a gap that the 16 bolts close but not easily. I was told the cams should rotate easily after installation.

I'm frustrated and don't have a local kawasaki repair guy to reach out to, or dealership to brain storm with... any sugestions would be GREATLY appreciated.

[smokeysevin]

Are these the same cams you took out of the motor? Are you sure you have them back in their proper locations? Are you using the cam cap that came with the motor?

I have had one of the oil rings on the piston pop out when installing the cylinders which causes the motor to lock up.

Sean

[BigDog9721]

Sean, same cams, installed cams as the service manual says, and same cam cap (cover). I'm thinking a stuck valve or 2... after i had the valve job done, the block sat for a year before i installed it... in my garage.

[smokeysevin]

Sean, same cams, installed cams as the service manual says, and same cam cap (cover). I'm thinking a stuck valve or 2... after i had the valve job done, the block sat for a year before i installed it... in my garage.

When they did the valves, do you know what they actually did? If they cut the seats on the valve and didn't re-shim or cut the tips you could have the valve clearance at 0 which could be part of the issue.

Just to double check, the cam with the cam position nub is on the side of the head with the cam position sensor?

Sean

[BigDog9721]

Success! I went back to the machine shop that did the valve job and added shims.... all is good. I brought the engine in and they helped me install cams, cam chain, and cam cover. Come to find out, the torque to turn over engine was normal... obviously I not knowing what to expect, didn't know.... now i do! So now on to the next phase... Sean thank you for your help on this... on another note, do you know where i can borrow/buy a shaft wrench? (LOL).

[smokeysevin]

Success! I went back to the machine shop that didi the valve job and added shims.... all is good. I brought the engine in and they helped me install cams, cam chain, and cam cover. Come to find out, the torque to turn over engine was normal... obvioously I not knowing what to expect, didn't know.... now i do! SO now on to the next phase... Sean thank you for your help on this... on another note, do you know where i can borrow / buy a shaft wrench? (LOL).

For the big finger coupler? I have a spare one I can sell or you can use the flats on the driveshaft with the rubber damper in it depending on what you are going to use it for.

Sean

[BigDog9721]

For the big finger coupler? I have a spare one I can sell or you can use the flats on the driveshaft with the rubber damper in it depending on what you are going to use it for.

Sean

It's part number 57001-1551, do you have a picture and price?

[smokeysevin]

Ahh, the other side. Nah, on that I have always just used an adjustable wrench or whatever size wrench it fits. It has been a while.

Sean

[BigDog9721]

any recommendations on re-installing the coupling?

[smokeysevin]

any recommendations on re-installing the coupling?

Clean the threads really well on both parts, use anti-sieze on the crank snout, heat the coupler up with a heat gun just a bit, and hold the crank with air pressure in a cylinder (works best if the cams aren't in yet since you can set 2 of the cylinders at bottom dead center, throw 50 psi of air pressure in one and you have a locked motor.) then you can spin the coupler on easy either with the kawi tool or a rectangular crow bar. Just make sure you don't damage the fingers on the coupler.

Sean