Yes your right!! All that it means without the stat is it takes longer to boil giving me longer to put the switch on.
But you are right it should have a stat!
I tried to get a pressure test a few weeks ago but due to the location of the cap they could not get the tester on. After it has been running for a few weeks I will get a block tester that will tell if any combustion gases are in the coolant.

Also talking to a radiator specialist today I am wrong about the pressure!! The pressure is created by the water getting hot not the waterpump! As the water heats up it expands and then the rad cap stays shut until the pressure builds up on the radiator and it lifts the cap when it reaches it's limit.

I can easily press the hoses together but there is enough pressure to lift the cap.
Maybe when I first had it and was getting it going all the revs has done something to the gasket or block? I find that hard to accept but possible. There are absolutely no other signs of anything amiss if I don't let it boil it looses no water, nothing in the oil or water, engine watertight and no tell tell signs coming out of exhaust. Plus the bike goes like a rocket and is always cool unless it is in traffic or is being reved at standstill.

The thought of removing the head and block is to daughting to think about with the engine I have.

I really don't know what else to do? My neice had a custom Honda that did the same and the RAC man just wired the fan to be on all the time. She rode it for 3 years like that after replacing the rad cap and fan sensor.

I don't want to do that for wearing out the fan, but like everyone else who have been so kind to try and help, I am sick of it and as I said I have no idea what to do know!

Thanks for posting!!!!!!!

10 second job and all is fixed!! No pressure was indeed the problem and totally made up that I fixed it ! Thanks to everyone who tried to help and took time out to post!

Thank you all again
Mark

What was it?????

Feel really stupid as it was a total shot in the dark! I couldn't work out why no pressure in the system yet when it got hot it would get passed the rad caps! The other morning I flushed it out again and put the stat back in. Much worse so I drained out the coolant and put in new again! I thought I would bleed it again squeezing top hose, and as soon as I squeezed the top hose bubbles and coolant went straight to the expansion bottle even though the rad cap was on and the bike was still cold!

So it is the rad caps I thought and went to go a high pressure one! I didn't get to the phone but had a close look at radiator neck. Do you know there are THREE hoses that go into top of radiator? One big one and TWO small ones, one to the expansion tank and one that comes off the back off the block as an engine bleed. Both are same size and just disappear behind the frame!

Well some time ago, someone put them on the wrong way round so in fact the expansion was getting a direct feed from the radiator BELOW THE RAD CAP! switched the two pipes back to the right way around and had a perfect pressurised cooling system and was extactic!

All the time i felt ecstatic but it must have been like it for ages and maybe the chap who had it before me sold it cos it was overheating? The pipes needed a big wiggle to get them off so it must have been like it for ages!

I didn't say anything before as I should have got it straight away, and all you good guys were trying to help me!

All I can say is thanks and yes I feel pretty stupid!

All's well that ends well..and a great big thank fuck for that!

Yes you put it very well lol

Glad you found it
It's always the simple things huh !!!

Yeah always !!! At least me and the forum agreed on the no pressure! Thanks again!