Kz900 won’t rev over 3k

[kev edwards]

On the off chance do you have resistor plugs and caps in it as this will also create problems, needs to be one or the other, you can guess how I know.

[Nick.s]

Hi Chris, I checked and rechecked the cam timing. I got the arrow on the exhaust cam dead on the top of the engine block, then counted the 28 teeth. Then I checked several times again, Maybe I should have another go at it. Can you remember which way yours was out?

[z1bman]

post some photo's of your valve timing especially the position of the cutaways in the end of each cam. the cutaway should be half above the cam cover mating surface & half below. i have posted a photo in one of my earlier comments its the most accurate way of setting the valve timing

[zed1015]

Cam timing should be.
Cylinders 1-4 on TDC.
Arrow on exhaust cam facing forward level with top of head.
Count 28 pins back from the pin above the arrow.
Don't know why they didn't just say count 29 pins starting at the arrow as that would have been much more simple and clear and saved a lot of confusion for some over the years.

[marmck]

https://www.youtube.com/watch?v=BUaao5mMylU Round about 28mins is camchain setting!

[kev edwards]

[Nick.s]

Hi Kev, are you sure your diagram is correct? I thought the first pin was where the arrow was pointing.I’ve been using a book by Chris rooke and that’s what he said. The daft thing is I mistakenly had it right in the first place and I still had the same problem. Oh well I’d better put it right anyway

[zed1015]

Hi Kev, are you sure your diagram is correct? I thought the first pin was where the arrow was pointing.I’ve been using a book by Chris rooke and that’s what he said. The daft thing is I mistakenly had it right in the first place and I still had the same problem. Oh well I’d better put it right anyway

The diagram is correct.
Either count 29 pins from the arrow or 28 pins from the one above the arrow.
An easy way to keep pin count is to use a white tyre/paint marker and dab each pin as you go.

[Nick.s]

I must apologise to Chris rooke, his book does say the pin above the arrow, I just took it that he ment the pin next to the arrow. Like you said, it would be better to say 29 from the arrow

[kawasaki_man]

Nick,
here is a picture of the set-up done on my bike a while ago. Any easy check to make sure if you are on pin28 and not 27 or 29 is to check the "orientation" of the pins with reference to side plates. In my case even pins point "left", odd pins point "right". At least this gives a very quick and easy visual check without having to count pins when the top tensioner is in position.

[Nick.s]

Thanks for that, I’m going to try again tomorrow if I’ve got time.

[Nick.s]

I’ve made sure that the valve timing is correct, unfortunately it made no difference.
I’m trying a different set of carbs next (thanks Gus)

[zed1015]

The ones in your previous pics are 26mm.
I can tell the size of these at a glance from a mile away and by the proximity of the venturi bore to the casting around the air drilling for the choke.
26mm bore doesn't touch the casting, 28 puts a flat on the side of it and bored out to 30 will nearly break through.
Post a pic of the engine side and what you are measuring.

Here's a pic (although a bit blurry) of my 26's I bored out to 29.4mm.
See how the bore has cut in to the raised wall around the air passage.

[Nick.s]

Your right, they are 26mm. I just checked again

[maxxx1000]

Are you doing a Mechanical Synchronization of the carbs after you put them back together?