Kz650 b3 no compression on 2 and 3

Scirocco wrote:

Due to the large valve clearance and zero compression, i bet you will find some bent valve stems  on #2 and #3

And as the compression is low on 1 & 4 the whole top end needs a refresh, possibly a rebore. No point in doing half the job whilst it's this far apart. 

Scirocco wrote:

Due to the large valve clearance and zero compression, i bet you will find some bent valve stems  on #2 and #3

 

Or given how long it has been standing it may have broken the rings on start up if they were rusted to the bores

I wouldnt be surprised if i do find some bent valves

Or possibly broken valve springs.

I just ordered a complete top end seal kit from z1enterprises. I already got the new cam shaft end plugs. I took the exhaust off last night. Tonight if i have enough energy after work ill take the carbs back off (for the 3rd time) and then take the head off. I gotta say though the most painstaking thing ive done on this bike is removing and installing the carbs. Its the worst. Even with a heat gun to soften the boots up and my 3d printed tool i made for carb boots its still my least favorite thing to do on this bike. 

faceplateman wrote:

I just ordered a complete top end seal kit from z1enterprises. I already got the new cam shaft end plugs. I took the exhaust off last night. Tonight if i have enough energy after work ill take the carbs back off (for the 3rd time) and then take the head off. I gotta say though the most painstaking thing ive done on this bike is removing and installing the carbs. Its the worst. Even with a heat gun to soften the boots up and my 3d printed tool i made for carb boots its still my least favorite thing to do on this bike. 

Please tell me you didn't order the Athena kit! 

No its the vesrah kit

The athena kit looked like it had the wrong exhaust crush washers. 

Well i just took the head off and all my problems seem to be valve related. All the cylinder walls look nice and shiny. No scoring or anything. The valves however are a different story. All the exhaust valves look like they are slightly open. Number 2 ex valve is even more open than the rest. Next step is to buy a valve compressor and take all the valves out. Im gonna replace all the guides and springs. Repair any damage to the seats and replace any damaged valves. Completely clean everything and replace all the seals. 

Looking at the "witness marks" on the pistons it appears the exhaust cam timing was incorrect. I would suspect the valve stems are bent as a result of impact   (probably worth measuring your piston heights before putting the head back on just to make sure you haven't bent a rod (unlikely as it looks like the "mechanical love making" was gentle !!)

Hard to say if you have any valve issues until you remove them and see if they move freely and if the seats are OK.

Don't forget to change the valve seals and check the valve guides for wear.

hardrockminer wrote:

Hard to say if you have any valve issues until you remove them and see if they move freely and if the seats are OK.

Don't forget to change the valve seals and check the valve guides for wear.
 

He covered all of those things in his last post

Im gonna replace all the guides and springs. Repair any damage to the seats and replace any damaged valves. Completely clean everything and replace all the seals.