Hello all,

New around here but I will cut straight to the chase and pick your collective brains.
I have a 1WG pre EXUP 400 that I picked up cheap as a trackday project. It has a few running problems that I need some ideas on.
It starts up from cold straight away on choke and ticks over nicely, as I decrease the amount of choke it seems as if the right hand outer pot isn't firing properly( exhaust pipe cooler that the others, though hot when on choke) I thought the pilot jet may be blocked so dropped the carbs off, to be honest they looked quite clean inside but I blew out all the jets anyway, put it all back and still the same. I have also swapped the plugs over to no avail?
It also seems reluctant to rev above around 7/8K and coughs and farts a bit.
With it running on choke, I guess the problem must be carbs, is this a common problem, anybody offer any ideas
I bike has been stood for a while so maybe some of the internal passages are gummed up?

Ta in advance

Ian

clean the fuel filter? Drain the fuel and put new in to start with, have you checked the coils as if its only one cylinder maybe there is a problem with that? Also you could take off and clean the pipe into the carb in question incase it has got a load of crap in from standing. What is the inside of the tank like?

I thought 1 coil did the outers and the other the inner 2 cylinders so surely a pair would be running rough, suppose it could be a lead but why would it fire on choke? Tank is clean, will change the fuel though as I am not sure how old it is?
Are any of the carbs interchangeable on the rail so I could swap them over and try and pinpoint the fault.
Anyone got any good methods of cleaning out carbs internal passages etc?

Well spent the afternoon tinkering about, stripped down the carbs again, reset the pilot air screws, drained and re-filled with fresh petrol and she seems loads better. carbs could do with a balance I think but she now sounds sweeter. She also reved to 12K so things on the up. just got to sort a few other jobs (someones put new pads in calipers with sticking pistons ) change the oil and coolant and put on some new tyres and she will be ready for the track :D

Sounds cool.
Check the airbox rubbers haven't got hard as the airbox will be difficult to get on. Your right about the coils. Renew the fuel filter as it's cheap and is a service item. Just put a bit of carb cleaner through the fuel pipe but it sounds ok. I usually run a little carb cleaner fuel addative in the tank for a couple of fill ups

if you're racing you ccould get a more free flowing filter to help flow.

I'm just in the process of cleaning my carbs. The pilot screws are 3 turns out - is this correct? Can't find the info in the service manual....
Thanks.

I always set mine between 2 1/2 to 3 1/2 turns, so you are not too far out :D

torpytanktop wrote:I'm just in the process of cleaning my carbs. The pilot screws are 3 turns out - is this correct? Can't find the info in the service manual....
Thanks.

The manual I downloaded said 3 and a half, so thats what I set mine too