South West Bikers | Motorcycle Forum

hey all, im starting to regret trying to get back on to 2wheels.

Im at a standstill at the moment and i dont really know what to do next..
basicly bought a zzr600d, was running rough, so bought carbs from ebay, supposed to of been ultrasonic cleaned but cant guarantee. put onto bike, clean fuel and a new fuel filter. bike started up, but had to hav throttle open fully, would not idle, lots and lots white smoke coming from exhaust, also fuel is in with the oil. and a very strong smell of fuel. bike went bang, lots white smoke come up from airbox. day 1

day2, took carbs off, and had them cleaned by hand, apparently and balanced.. but again i cant be sure. put back onto bike, still same problem as above.

im looking to buy a engine from a chap who has been big help, been told by quite a few people it sounds like the floats are not working or could be the jets not seating correct.

do i buy the engine 1st and try the carbs i already have? or shall i buy the carbs 1st? tbh i would rather have the replacement engine, is it worth trying my carbs on that on first?

just been told that the bike used to have a hole in it, so leaked fuel. is it poss the engine is full of fuel?

Drain then oil and see if it has fuel in it , the only way to know for sure and cheaper than replacing the engine if not neccesary

Mervin wrote:Drain then oil and see if it has fuel in it , the only way to know for sure and cheaper than replacing the engine if not neccesary

thanks for the speedy reply, sorry forgot to say, yes the oil does have fuel in it.

i been told its the carbs, but they been cleaned apparently 2times now,, been told its needles not seating properly, been told its the floats sticking and not shutting off the fuel. been told its the fuel tank lol. HELPPPPP lol

what carbs are they? It certainly sounds carb related. Are you sure all of the jets are in the correct positions? Are the floats at the correct height? Is the mixture correct?

Spark, air/fuel, timing.

How could they balance the carbs when they were off the bike ?

You can do a 'rough arse' balance with carbs off the bike, it involves testing the slide spring tension when compared to butterfly opening I think. TBH though I dont know why anyone would bother doing it that way though as it is much easier with the carbs on the bike using gauges and the latter is matched to the engine and accurate.

Perhaps it is done this way first as a first step to the final balance?

devonbiker, how did the bike run with the original carbs, was it just lumpy and this was why you purchased different carbs? I wouldnt start it too often if at all if you think the oil has been diluted with fuel. The cause for fuel in oil is usually worn float needles, the needles do not seal very well and fuel drip drip drips through the intake. If the float needles are shot you may also see fuel dripping from the overflow on the carbs and this could be your fuel smell. If it is a mikuni carb I may have some used needles here that will fit.

Who is cleaning your carbs and how are they doing it? Once off the bike they are pretty easy to work on, you could do this job. If you have two sets you will have enough to make a one good set. Carefully take them apart noting where exactly everything goes and blast all the little orifices and jets with carb cleaner. Push fishing line through all of the passages, and blast them through with the cleaner. Do not damage the bore of the jets with wire or anything daft like that. Reassemble and try again. Watch out for any tiny o-rings that come away, they'll need to go back where they came from. Slides should move freely. Check seals and diaphragms for damage.

Good luck!

thanks for the reply dan, i reakon you should take a trip over here lol.
well 1st of all the bnike was runing rough as hell, not idleing, revving etc. so bout a set carbs off ebay.

got them ultrasonic cleaned from chap down road.. ( i have been told since then, he may not of actually touched them) what do you expect for labour costs of a fiver?. but he is pretty well know for tinkering with things, and he does get machines to work.. so im not sure tbh if they were ultrasonic cleaned or not?

anyway...

put back on bike, bike not idle, revs ok.. needed throttle open fully to start the bike...with choke on aswell.
mate came over, he took carbs away and stripped and cleaned by hand.. said he balanced the carbs,
put the carbs on bike, still wont idle, still lots white smoke and smells of petrol.. bike went bang lots white smoke come up from airbox, ( was told this is fuel getting into combustion chamber ) plus lots fuel in with the oil.

is it worth buying another set of carbs off ebay if the jets etc are knackered.. or can you buy the main jets etc seperate.

im really getting stressed now lol

I would have thought a jet could be broken, its just a hole through some brass really, nowt to go wrong.

Ultrasonic cleaning usually costs around a hundred pounds if done properly and when finished they'll look properly brand new. Also if someone has tried to balance them off the bike it would be VERY easy to [censored] it up completely. A half turn on the screws in the wrong direction could totally [censored] it up.

Take them apart mate and double check everything, you only need a few screwdrivers or sometimes allen keys. Clean them through like I said before, check the float needles. If it runs fine off idle change the oil, fit the carbs and try balncing them on the bike. Youtube it, its really easy once you have the kit.

Carbs from another bike could well work okay but they would not be balanced to your engine.

when you say check the float needles? what do you mean,, what should i look for, and what should they be like?

This one is okay.


This one is fooked.


Do not bend the tang when checking as that would change the fuel level and you dont want to do that.


Your carb may not be the exact same as this picture but it will be similar looking. This part of the carb is beneath the bowl on the bottom.

Here. Watch this too and you will see why I would be nigh-on impossible to balance carbs off the bike.

http://www.youtube.com/watch?v=Hr6_Qu348is

video makes sense, prob is my bike would not idle. think all you guys should come for a trip over lol.

ok update, took carbs off.. opened them up. didnt look like they were ultrasonic cleaned.. also carbs were all badly adjusted. some were half screw in, some were 2screws turned etc etc, so set them all roughly.. we will wait till the replacement engine comes to try them out,
then all we need to do is do a proper carb balance. hopefully prob solved.

just worried, dont wanna put the carbs on the newer engine.. if the carbs not fixed and hav the same problem again of leaking fuel into engine.

anyway for now, fingers crossed. we gonna take the engine out over the next few days..

maybe a good time to give the shock a lick of paint. bloody scary though taking engine out lol

Hopefully that'll be enough to get the bike started and then you can balance them and go from there. Carbs can be a pain in the prick sometimes. Working correctly the carb is as good as anything else and it is very satisfying knowing you can whip them off at any time to retune them.

dan83590 wrote:Hopefully that'll be enough to get the bike started and then you can balance them and go from there. Carbs can be a pain in the prick sometimes. Working correctly the carb is as good as anything else and it is very satisfying knowing you can whip them off at any time to retune them.

is there a way in which you can test the carbs? as in seeing if i do have dodgy needles etc. as the previous posts said, no ammount of cleaning will fix a knackered jet etc.