Installing cams

Im putting my motor back together to check valve to piston clearances.I put it at tdc #1/4,put cam chain on exhaust cam with sprocket mark lined up with eng.top,counted 28 pins ,installed int. on mark.put on roller tower.I also marked these pins and cam gear marks with a marking pen before dissasembly.Now the pen marks line up as before.But for some reason when i advance the crank my intake and exh. valves want to hit.I obviously did something wrong here .Any advice?

Roller tower between the cams goes on last, with both cams in place.

You may be off! Ha. Make sure the intake isn't 180 out of ccourse or the ex.! The engine should be tdc not the fire mark mark, right, ok I believe you. This is the compression stroke so the intakes should be closed and on the way to opening after the cam lobe travels over the top. Don'tsha know?:The in. is opening early or the ex. is closing late. If you don't figure it out you get nothing for christmas. And WE want to know!

Post edited by: nads.com, at: 2007/02/06 13:25

Post edited by: nads.com, at: 2007/02/06 13:26

While we are on this subject, let me ask a related question.

I also just reassembled my engine. When installing the cams, I followed the manual's instructions--turned the crank to 1-4 TDC, then installed the exhaust cam with the ">" mark pointing to the front. My concern is this. With the position of the chain pins in relation to the cam gear teeth, the > mark is not exactly flush with the head rim. It is actually about 1/4" above it. But if I were to move it one tooth down, it would be below the rim. Should I be concerned?

I did quadruple-check the 28-pin distance to the intake mark, so I'm sure that's correct.

I have not fired it up yet, but I'm getting close. Just need to put on my exhaust, and I should be ready to go. If it turns out that my exahust gear position is 1 pin off, is it going to damage my engine when I fire it up, or will it just run rough?

If you know it is off 1 pin fix it first.then with all the plugs out.rotate the eng. by hand while looking in the plug holes and you can see (with a light) if the valves and pistons are all happy .

It just dond on me that the cam sprocket(on the intake cam) is probably on the cam incorectly,because on #1 int and exh are not pointing in oposite directions.

mark1122 wrote:

If you know it is off 1 pin fix it first.then with all the plugs out.rotate the eng. by hand while looking in the plug holes and you can see (with a light) if the valves and pistons are all happy .

The problem is that I do NOT know if it is one pin off. For those of you who have experience with this, is it normal that the > mark would be slightly above the head rim at 1-4 TDC, or should the arrow mark be pointing exactly at the rim?

I have turned the engine over many times by hand, and have not heard or felt any "collisions", but I don't know if that would change with the enging running.

Any decking or a stretched cam chain will effectively make the chain chain longer. Cam lobes should be close to pointing "inward" towards eachother on the points side with 1 & 4 @TDC whitch is the T mark on the advance mechanism but with slotted cam sprockets, the degreeing process will put the lobes in the correct position even if the markes on the sprocket don't line up precisely with the head.

My guess is you're using the wrong marks. On a KZ650 marks are clear as day, no way to make an error. On a KZ900/1000 it can be deceiving, you can line up marks thinking they are the ones referenced, but there may be another mark which is actually the mark you want to use. The way I found this out was the hard way. If you turn your engine over and feel any resistance or any "clicks" it means the valves have butted and you'll have the intakes bent which can be verified with a clearance check. If you suddenly have gobs of valve clearance, you've done damage. This is a very common thing if you're not familier with the engine and cam marks, which I wasn't :sick:

Well, I reread and you marked the cams, sorry about that, guess it isn't what I thought

Okay, I guess I'm going to try to get some photos posted so you guys can double-check my work before I try firing up this beast. I'll try to do that tonight.

mark1122 wrote:

It just dond on me that the cam sprocket(on the intake cam) is probably on the cam incorectly,because on #1 int and exh are not pointing in oposite directions.

Looking at the motor from the igniton side #4 cylinder:

Exhaust cam - #4 lobe pointing back toward intake ports, the > will be at 3 O'Clock position.

Intake cam - #4 lobe pointing toward exhaust ports, the 28th pin mark will be at almost 12 O'Clock position. IF you have that, then the sprockets are on correctly. That doesnt' mean they're timed properly yet, just that the sprockets are positioned correctly.

If for some reason, you still have the rubber on the sides of the sprockets, DISREGARD the lines on the rubber. They are references marks for factory valve adjustment procedure ONLY.