Have you cleaned the carbs ???
It's always a good idea and these bikes are a bit prone to getting some crap in them. Warning tough, if you haven't ad the airbox off then you need to know the rubbers go hard and shrink a little making it hard to impossible to refit the airbox. New rubbers are available through Fowlers in Bristol but you have to quote your frame number (on the V5 as well as the headstock) before they'll do anything.
Check the fairing brackets - you can't get the big A shaped ones (middle front) so if they look dodgy be careful with them ... they're the same as FZR600 though.
Check the cables on the exup where they come out of the cable sheath, they fray which jams them.
When you service it - oil filters plugs etc ... change the fuel filter.
Lots of these bikes have the fuel tap broken so they get set to RES. Get a new one again from Fowlers and also get the lever and the screw that holds it. You have to remove the lever to take the tank off.

Evilchicken0 wrote:yes water is white smoke ... sometimes called steam

Hmm ... odd then cos white smoke has to come from somewhere and the only other way to get water into the combustion is through the fuel ... from the fuel tank ???

or just condenstion in the exhaust or can ?

i,ve got a gold mph converter in working order if you want it, got a grip mark on the gold bit where it was held to be unscrewed. You can have it for £7 posted if you want it, i can email you some pics if needed, also got a speedo cable to go with it if you want it make me an offer!
My initial thought was condensation on start up, me old landrover used to do it if it was stood for a couple of days. Admittedly theres a bit of a difference between the two though!

Thanks for the comments Evilchicken, Trev and Taggy. I just fired it up at lunchtime to check, it pumped out a little white smoke for a few seconds and then cleared up, it's definitely running rich at idle which makes me think the pilot jet needs cleaning at least.

My shopping list for bits to replace grows by the day it seems - spark plugs, air filter, oil filter, brake pads on their way already :)

Does anyone have a PDF manual that suits a 3EN1 at all? I have the US one downloaded but not sure if that's 100% accurate.

Taggy - I'll definitely be interested in your two parts if you can send me some pics please?

Evilchicken - would you maybe fancy meeting up Euston way one evening for you to give me your (much better informed than mine) opinion please?

sure - I pm'ed you my number
I'm around tonight if you like should get back at about 6pm

i got some nearly new brake pads but there for an 3ne2 both front sets and rear set
i bought a new set for mine thinking i needed them on taking the old ones out saw there got 1cm left on them all
but still put new ones on
you can have the whole set for £10 posted

Thanks for the offer Trev, I managed to get some EBC ones for my 3EN1 on EBay which arrived yesterday so won't need any for a while I think

Managed to commit a true schoolboy error last night, my K1200R is just a bit too refined and tells me when I need new fuel, well I ran out of fuel last night and when I went to turn the knob to reserve the knob wasn't there so had to push it 2 1/2 miles to the nearest petrol station.... Jesus, embarrassing or what? :D

I always think the hardest lessons are the best lessons in biking, I won't be doing that again.

Well .... I did say it was probably on reserve due to a broken tap ... oh the smuggness of it all.

Try dot 5.1 fluid too.
If you want to change to braided hoses then know that a 2 hose race setup will touch the clocks and fail an MOT. Change the master cylinder to a 3TJ type or use a 3 hose setup but measure the originals to get the right lengths

Cheers for the tips on the brakes, will try to get a 3TJ master cylinder... any none FZR400 ones fit as an alternative do you know?

Quite ironic you mention the tap isn't it, you can have the smug moment, I deserve it :)

Thanks for help folks.

Most master cyliders with a separate reservior will fit cos they're mainly 22mm bars.
I've put a Brembo radial master on my TJ it works well but the lever just touches the clocks on full lock ... I'll need a sympathetic mot station