TOPIC:

Hi - So the old 82 KZ1100 needed cylinder head O ring seals replacing - and they arrived pretty quickly so I disassembled the top end and took off the head.

2 O rins gone altogether - no wonder I was getting oil leaks !!

Any way as I look at cleaning and putting it all back together it suddenly occurs to me that the position of the cams shaft markings when I took them off - were not the same as the positions shown in the manual for TDC. I did line up the TDC mark on the timing wheel before taking it apart - but now I see the EX and arrows marks are about 30 degs behind where they should be pointing at TDC according to the manual - and I realise if I turn over the engine once more they would have been in the stated position. (probably)

So assuming these engines have overlap between cam revolutions on the valves - there is a good likely hood if one gets the timing out a bit - then the piston could hit the open valve somewhere.

SO - I am assuming (and asking ) - are the marking positions in the manual defined at TDC on the compression stroke or the non compression stroke.?

I did not mark the chain and cam sprockets with nail varnish or whatever as I will simply reinstall the cam shafts according to manual settings (I did draw them relative to their position when I took the off - and that's how I notice now that whilst the TDC mark is aligned on the timing wheel - the camshaft marking positions are not as shown in the manual)

I've read that at TDC on the compression stroke - ALL the valves are shut ?? Is this correct?

So - what now ? Can I turn the engine over one revolutions to TDC on compression stroke and then reassemble? (I have to clean the top of the pistons of carbon anyway - so have to bring the other 2 pistons up to the top to clean them - turn over the engine. )

Am I thinking right here - or talking rubbish and if so - please tell me its rubbish and what to do to A. - clean and B. - reinstall the camshafts.

Thank you Guys

You're overthinking it. TDC is TDC, there is no stroke in mind when you line that up. The cams turn once for every two revolutions of the crankshaft so if you are turning the motor over with the cams in place, the markings will only line up on every other revolution of the crankshaft. To answer your question, one of the cylinders will be at the top of the compression stroke when you are at TDC but the other three will not.

You can turn the motor over to your hearts content with the head off, just make sure you support the chain so it doesn't fall/bunch up in the crankcase. The manual will have the correct procedure for installing the cams etc. and how to check. While I've never done an 1100, I've done many two and four cylinder bikes over the years and the process is fairly similar.

At TDC TWO of the pistons will be at the top. They run in pairs. One of the two will be on the fire stoke the other will be on the exhaust stroke. All Kawasaki 4 cylinder 4 stoke engines run on the wasted spark principle. Both the cylinders will spark but only the compression stroke cylinder has fuel in it and will fire.

Very good explained Warren. Two turns of the crank are one turn of the camshaft(s) on all 4 stroke engines.

Warren3200gt wrote: At TDC TWO of the pistons will be at the top. They run in pairs. One of the two will be on the fire stoke the other will be on the exhaust stroke. All Kawasaki 4 cylinder 4 stoke engines run on the wasted spark principle. Both the cylinders will spark but only the compression stroke cylinder has fuel in it and will fire.

Nice to save some coils also
Since you can use one coil for two pistons.

Good Fortune!

Thanks Patton!

Have that straight in your head in the morning, and the rest of your day should run smoothly.

Well that was rewarding - thank you everyone for your education. I understand all that has been explained but still need to be sure I understand and can act on my original question/concern which was -

No 1 piston is moving to the top of the stroke twice in every full sequence - to the top under compression and to the top again one revolution later on exhaust .

The position of the cams is therefore different relative to all pistons between first stoke and 2nd stroke. So - the manual just says the markings on the camshafts are X when No 1 piston is TDC - BUT at the top of its stoke on which of the 2 strokes?

Now - if you are saying the camshaft/cam positions are the SAME position every time No1 piston reaches the top of its stroke - I can then understand why I am over thinking it. IS THAT THE CASE? (or - are the cam shafts in two different positions for each of the strokes? - common sense says to me they must be as there is different activity happening in each stroke - )

You can see how we never really study cam positions to valves - ignorance mans lack of understanding. The attached stroke pictures shown in the thread certainly show cams are controlling different valves in each of the TDC positions of piston 1 )

If I am correct then which stroke are the camshaft marks aligned to?

thanks Greg

Anyway - irrespective - reassembly - as I understand it - with No1 piston at top of stroke - I just put in the cam shafts with the marking in positions shown in the manual and count off link numbers correctly. The valves are all shut anyway before putting on the cam shafts - so the cams will depress the valves at correct positions if we follow the marking instructions. ??

Correct.

When you think about it, lets say by chance No4 is at TDC on the compression stroke when the engine stops. Which means No1 will be at the top of the exhaust stroke.
You take the cams out and replace them as per the manual, without turning the crank.
All you have done is moved the cycle through 360 deg so that No1 is now at TDC on the compression stroke and No4 is now at the top of the exhaust stroke. and due to fixed lobe positions on the cams No's 2 and 3 have to follow.

gregoryzim, do you have a Service Manual?

gregoryzim wrote: Now - if you are saying the camshaft/cam positions are the SAME position every time No1 piston reaches the top of its stroke - I can then understand why I am over thinking it. IS THAT THE CASE?

No, the cams will be in one of two positions every time piston 1 hits top dead center. The part I was trying to convey that you are overthinking is that there is no difference on the "bottom end" of the motor which stroke the motor is on. As long as the bottom end of the motor is at TDC when you replace the cams you are good as long as you follow the proper procedure. The cam and valves determine what stroke the motor is on, the bottom is just "up and down" to put it simply. When assembled, the cams will line up the first time you rotate the motor to TDC and then they will be off the second time you rotate the motor to TDC, line up again the third time and so forth.

Do you have the manual/procedure? There are specifics to checking the chain, installing/adjusting the tensioner etc. that need to be followed.