Running on choke and cutting off

[Lewis400]

Hi Im new to the site,

Ive bought my first bike this week, a K reg ZXR400 in dark red.

Anyway the bike wouldnt start, its been standing for nearly a year.

We charged up the battery and put fresh petrol in it, and it fired but only with choke full on..

Once you put any throttle or choke off it cuts out straight away.

My mate rekons it the carbs that are just blocked and full of toad, and need cleaning and a general service.

I bought the bike for £300, with scorpion exhaust, and 30k miles..

Im not doing my test till september, so Ive plenty of time to give it a service and what not.

Any help/advice would be greatful

Thanks
Lewis.

[thomp1983]

taking the carbs off and cleaning them would be a good place to start, it will only cost you a can of carb cleaner and some time but be careful you don't damage any of the carb internals. how long have you left the choke on before trying to rev it? i know mine won't rev freely and can cut out it not left on full choke for at least a minute or so (usually the amount of time it takes me to put earplugs in, lid and gloves on.) if it's been stood a couple of weeks.

chris

[Lewis400]

Thanks for that, the bike is currently at a mates house, going to pick it up in a couple of hours, bring it home and start stripping.

Ive been quoted £60 to the job, and 40 for a service + parts.

Im going to try leaving her on/running for a while see how she is.

[Tirpitz]

Before you waste time stripping everything down drain all the old petrol out of the tank and carbs. Put about a jerry can worth of fresh in plus a dose of carb cleaner. Start the bike up again then turn off and leave it to stand for a day or two to get the cleaner working in the carbs. Then start again and if you can get it to run ok-ish take it for a run. You might well find that carb cleaner alone will dissolve all the gum in the jets and save you a lot of work. I'd only do a strip if I couldn't clean them this way.

[Lewis400]

Thanks for that,

I found out yesterday that its hasnt had a oil change in a while. So wednesday its booked in with a mate whos works at a local motorcycle shop.

Its having a service, new spark plugs, oil change, carbs cleaned and balanced, and its having a pre MOT check.

Im doing a good deal with him, I get parts and clean his van (im a valeter) and he does the work whilst I do

Got my theory next week aswell. So need to get the bike sorted and mint before I do my test

Will update with pics of dirty carbs for other users to have a look, if they had the same problem.

[Tom mccrea]

I had the same problem with mine, drained the carbs, sprayed the hell out with carb cleaner, drained the tank,gallon of fresh petrol with redex added and she went ok at idol, revving off the throttle again which is handy!! Hopefully putting it together today to take out for a run. I also changed fuel filter as it was clogged with crap and fuel pump as water came from the carbs when I drained the bowls

[Lewis400]

She now runs like a beaut!!


Carbs got taken off and stripped, and re jetted. 2 jets were blocked.

Uprated NGK Plugs, fresh oil, oil filter. Drained old petrol, and 5ltrs of fresh.

All it needs now is carbs balanced (as he forgot the machine at home) and a new air filter, ordering a Pipercross next week.

It now idles perfect, and revs nicely with a couple spit of flames

Took it for a little run round the estate, runs smoothly except getting too much air due to nakerd air filter, and carbs are not opening together the same time.

But all in all, very pleased!
Thanks for the help/advise guys!!

Lewis.

[Tom mccrea]

Wish mine idoled perfect!! Balanced etc and still up and down but from what I gather it's a zxr and that's what they do....

Heath to enjoy her....