A tick in the engine head after rebuild 93 XJ600 seca II

The engine was just rebuilt from the ground up and the problem is, when i disassembled it i made the mistake of mixing up the valve tappets that house the shims. I've taken the time to take the valve cover back off to measure the clearance between the cam lobes and the shims and everything seems to check out. After i reassembled it still makes the ticking sound. Once it warms up the sound goes away but when cold it makes a distinct ticking sound that does not sound good. What else could it be??

 

Re: A tick in the engine head after rebuild

A leak at one of the head pipes. Quite often, tiny exhaust leaks sound deceivingly mechanical.

Or, you have a sticky bucket because you mixed them up. How many miles were on the motor before the rebuild?

 

the odometer says 19426

 

You say everything seems OK, are you not sure of your measurments. The valves are either in spec or they are out, there is no inbetween.

 

the clearance for the intake side checks out but the exhaust wont measure. I'm told by the book that the clearance is is .008-.010 but i cant get the .008 under any of the exhaust lobes and that's the thinner of the 2 sizes. So that's tells me that all four shims are too thick, but that's impossible. And as far as a possible sticky cap goes, how would i clean the built up film on them?

 

The shims aren't "too thick" (well, actually they are now) more likely you either mixed up the shims too or depending on what the "rebuild" consisted of, those clearances are now tighter so they'll need re-shimming.

Did you check the clearances before the rebuild?

What exactly did the "rebuild" consist of? Were the valves lapped?

A sticking bucket wouldn't be caused by the build up of any film, it would be caused by a mis-match in the tolerances between the bucket and the head. At least that's what I was alluding to.

 

nothing was rebuilt in the head. The intake shims were not mixed with the exhaust shims. I admit i was too eager when i was taking things apart, i did not measure the clearance before i disassembled. The only thing that happened was the exhaust shims were mixed. As i said before, the intake side i figured out easily but the exhaust side is proving to be more of a mystery.

 

Then the chances are good that the exhaust valves were tight to begin with. At 19K miles, if they were completely neglected it would be quite possible for a few to be dead-tight.

Your "tick" could be the beginnings of a burnt valve. I'd get the exhaust side in spec before running the motor any more.

Just out of curiosity, what exactly did the "complete rebuild" consist of, and why did you rebuild a 19K motor?

 

Calling the engine rebuilt from the ground up is incorrect if the head was untouched and the valves are tighter than spec.

You need to get the clearances correct before you have further problems. Can you fit ANY (smaller than spec) feeler gauges in the exhaust side?

As previously mentioned, check the exhaust gaskets, a small leak can be very misleading and sound mechanical.

 

The valve tappets did not make any noise before the rebuild, they can be removed and inserted with no resistance. The rebuild consisted of a tear down to the crankshaft. A seal needed replacing on the shaft, and i replaced the crankshaft bearings and the connecting rod bearings. From there just a hone on the cylinders, new rings and a gasket kit. The reason for the rebuild was the leaky seal on the crankshaft and there was a vibration in the engine at 4k rpm in every gear while driving. Now i know assumption is the mother of all #$%& ups, but i assumed the vibration was because of bad bearings due to the previous owner dumping the bike at one point in time. They did look pretty bad. I know its not an exhaust leak.