How many miles are on this bike?

 

The intake valves are the ones closest to the carbs and the exhaust valves are the ones towards the front of the cylinder head closest to the exhaust headers.

 

thanks again mate, Ive checked all the vales clearences and they're all OK, the gasket hower has an inch of it missing and is very brittle. Am I right in assuming that this could result in poor compression and I should replace it with a new one and some sealent before I put the valve cover back on, or would the old one do?

 

...and the bike has done about 24k miles

 

No, the valve cover gasket has nothing to do with cylinder compression. What a crappy gasket WILL do is leak oil all over the place and make a god-aweful mess. It won't make any difference to starting but needs to be replaced anyway.

The three basic things you need for it to start are spark, fuel and compression. You need to verify those before worrying about anything else. If you have those three, even if the details are off (low compression, bad timing or mixture), it should at least cough and fart when you try to start it.
After sitting for so long chances are the tank is rusty inside and the carbs are full of crud after only a few minutes of cranking. So too the plugs will be corroded and shot, needing replacement. Check and verify everything.

If you crank it for a minute and then pull out a spark plug you can check if fuel's getting through as the plug should be wet/damp with fuel. If it's completely dry and the air that puffs out of the hole doesn't reek of fuel then you're back to the carbs. If the plugs are visibly wet then pull the tank off and check the connections to the ignition coils as they could be corroded. I'm sure I mentioned how to make sure there's good spark in a previous post.

 

Hi Guys

I have finally managed to get the GPZ600 started as long as its on PRI and then I can switch it back to normal straight away, but only if the choke is fully out?

compression is 150
changed all the plugs
new oil and oil filter
new air filter
and loads of other stuff done to it as well

...It starts great now as long as the choke is out fully, as soon as I push the choke back in, the revs just drop and it cuts out unless I pull the choke back out again and it revs back up?

I thought of a fuel block, but then if it had a blockage, would it start even with the choke at all?



...any help at all with this would be so appreciated.

thanks guys

 

Hi,

Recently joined the forum and have the same issue.

did you get it running?

mike