kawasaki 550 cutting out

[mentalboy]

Did you hone the bores whilst it was apart?

...and I would presume that if you went to the trouble of lifting the head that you popped the valves out, checked, cleaned and reground as required???

Kwak IL4's are reasonably easy to time, presumably you put a new head gasket in place?

Are your pistons the two ring type or two plus oil screen, what kind of clearances did you measure between bore and pistons?
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Make mine a Corona.

[Jay2903]

[Jay2903]

i just realised. I removed the tappets and shims without taking note of where they came out and put them back in randomly. would that cause zero compression or just some other problems later ?

[mentalboy]

[mentalboy]

I am a little confused, that someone with the mechanical aptitude to set up carbs after fitting pods would not think to check valve seats. Especially when compression is the reason the head came off in the first place.
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Make mine a Corona.

[Jay2903]

[Jay2903]

[Jay2903]

So
I removed the shims, measured them then put them back in with the intention of measuring valve clearances then deciding what size shims belong where. However i had some trouble.

I followed the manual and rotated the rotor until the T 1.4 mark lined up. I was expecting to be able to "check which two inlet cams, numbers 1 and 3 or 2 and 4, have their lobes pointing away from their respective valves, this being the position of max clearance." however cam lobe 1 was pointing away from its respective valve but lobe 3 was pointing towards its valve.
what have i done wrong ?

[bikenut]

I do hope you did not mix up the camshafts ?

Be very careful what you are doing ( bit late for that but still ) .

If pistons set half way up the bores, a d one camshaft is removed, then it is safe to rotate the remaining camshaft, but do not rotate the crank in this state.

Remember convention as to which is number one and firing order.
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[mentalboy]

Sounds like one camshaft has been installed 180 degrees out of synch.

EDIT: Note about previous post, you can rotate the crank as often as you like when the camshafts are out, the valves remain closed if the cams aren't there to open them!
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Make mine a Corona.

[Jay2903]

[bikenut]

yes, but what about the chain ? I can just see jay ( or anyone else now ) whizzing it over on the starter not giving a crap about the chain, can't you?
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[mentalboy]

[Jay2903]

[Jay2903]

[Jay2903]

[mentalboy]

[Jay2903]

[/quote]

It wasn't aimed at you, Mr Nut appears concerned that anyone else reading my posts would take them out of context.[/quote]

oh i see

[bikenut]

Sounds like one camshaft has been installed 180 degrees out of synch.

EDIT: Note about previous post, you can rotate the crank as often as you like when the camshafts are out, the valves remain closed if the cams aren't there to open them!

yes but what about the cam chain ?

so don't rotate the crank at all, cam chain will "bunch up" on crank etc and cause real expensive and possibly terminal damage.

Even if the cam chain was held taught, I would be reluctant to want to rotate the crank.

Can you rotate the cams in situ with the pistons at half stroke ?






nope, valves run real risk of "tangleing" with each other, more damage.

As you know the whole world views what seen on here.

How you getting on Jay ?
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nuts about bikes

[mentalboy]

[bikenut]

I am a little confused, that someone with the mechanical aptitude to set up carbs after fitting pods would not think to check valve seats. Especially when compression is the reason the head came off in the first place.

EDIT: Note about previous post, you can rotate the crank as often as you like when the camshafts are out, the valves remain closed if the cams aren't there to open them!

If pistons set half way up the bores, and one camshaft is removed, then it is safe to rotate the remaining camshaft, but do not rotate the crank in this state.


What are you wittering on about? Valves do not 'tangle' with each other. If you rotate the cam with chain off you won't be doing it on the starter and it's pretty easy to feel piston valve resistance when turning a cam by wrench.



kwak gt550 8 valve dohc

With cam chain off and both cams in situ, are you saying its safe to rotate a cam shaft and the valves will not "tangle" ?
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[mentalboy]

[Jay2903]

[Jay2903]

[/quote]

Valves may well clash but never 'tangle' with pistons, hence why one turns a camshaft slowly using a hand tool when one is working on the valvetrain. Turning in this fashion means that you can feel if there is contact and thus avoid damage. It does not matter if the two come in contact with each other using this method SO LONG as one is not a muppet and actually stops turning in that direction.
It doesn't matter whether it's a 4 stroke 125, a GT550 or a V8 Ford this applies to any vehicle (even better if you have a non interference head). Turning the camshaft is not the issue but the speed at which it is turned and not forcing it when there is resistance - which could mean any number of things, not just piston valve interference.

I feel that this thread is becoming derailed. My quals are more than 35 years both tinkering and being paid to tinker on engines some small (eg Stihl certified repair technician, amongst others) and some that are bloody huge or expensive, or sometimes both, but mostly bike engines. I built my first engine when I was 13 (a BSA C15 that came in a mess of boxes), I'm about to strip the heads off my 4.0l V6 SOHC Ford (see if google will tell you how many mechanics you can find that are willing to tackle that particular model!!!) and you won't find me regurgitating 2nd-hand googlefu - any OP can find that kind of info. If you look hard enough you might even find a couple of my rebuild project threads on BCF.
How about you Bikenut? Care to share your extensive mechanical background with the folks of BCF?[/quote]

wow thats quite the portfolio.
Being a 20yr old with nearly 7 years experience as a bicycle mechanic but only moderate skill in sorting carbs and electical problems learned from fixing up an old cg 125 i shall be taking your advice on board.
(however i was i did know to turn it by hand to see if pistons where hiiting valves)

[bikenut]

how you getting on jay ?

If pistons set half way up the bores, a d one camshaft is removed, then it is safe to rotate the remaining camshaft, but do not rotate the crank in this state.

pictures equal a thousand words, hope they upload to here.

So, the picture of the valves is from a haynes gt750 manual but the proportions will be about the same for the 550.

The chain picture suggests that the cam chain may "dangle" out of harms way, but may still bunch up and/or get caught up with the primary chain, so why take the risk.

Can you rotate the cams in situ with the pistons at half stroke ?






nope, valves run real risk of "tangleing" with each other, more damage.

As you know the whole world views what seen on here.

So, with pistons are half stroke ( so no danger of valves meeting pistons, which is why I said that ), and cam chain removed from cams, choose a cam to rotate., for valve clearance measurement and possible adjustment via the under bucket shims.

The non rotating cam will have a valve open.

As the chosen cam is rotated and opens valves, eventually it will open a valve next to the non rotating cam already "open" valve.

The valves are "inclined" in the 550 and 750, as shown in the picture.

The rotating cam will be difficult to rotate in control as fighting spring pressure, and, can become uncontrollable due to "whip" ( due to the force of a closing valve spring tending to "rotate" the cam, with some force ).

The valves dont have to open much to become "TANGLED" !! with expensive results, which is why I said to remove one of the cam shafts to enable the other to be rotated safely, for valve working clearance measurement and adjustment via the under bucket shims.

Jay, set pistons at half stroke paying particular attention to the cam chain, which can be tied up out of the way, just like you did when you did the head off and on.

Select the buckets that are going to be used for say the inlet valves and place near there holes.

With only the inlet cam in situ, gather all the shims and select the thinnest 4 for temporary fitting to ascertain the correct shim size for setting the valves working clearance to spec. RECORD THE THICKNESS ETCHED ONTO THE SHIM AND TO WHICH VALVE AND BUCKET THEY ARE BEING FITTED TO.

Fit the shims, buckets and cam, take care and tighten cam caps to torque.

Now you can safely turn the cam and measure each gap RECORDING the data.

Remove cam, buckets and shims. The buckets will be refitted to the holes they have just come out of, do not mix them up !

Now you can calculate the required shim for correct valve working clearance. The 750 has quite a wide tolerance, which may be the same for the 550. Aim for the "middle" valve, 3 to 7 thou, so set to 5.

When the correct shims have been selected, keep them in order, ie valve to bucket to shim.

Next, repeat the exercise with the exhaust cam etc..

This is the quickest way for your predicament.

When entirely happy, refit everything being particular about the cam chain and its proper fit on the crank, the "sag" between cam sprockets and the tensioner.

If the cams are timed correctly it is safe to turn the crank with the cam cover ( it has a between cam sprocket rubber "chain sag" slipper ) off, but only in proper direction of rotation and very very slowly. Valve clearances can be measured and recorded in this state.

If yours has the cross wedge cam chain tensioner, you will have noticed it auto adjust when the cam cover was taken off. You will know that the tensioner has to be removed and "cocked" before cam cover is refitted, then "released" to auto adjust when the cam cover is fitted properly.

Hope this helps.
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