ZZR250 Quick Question

Hi guys,

I've been looking for a decent forum for a while and this seems to be the place.

Quick question, Like most ZZR250 owners i'm having some problems with my bike

Now i've paid to have the carbies removed stripped and cleaned with new neddles and seats installed. Picked the bike up today and it's still doing the same old, dies at idle when hot. Sounds like a mower on steroids etc. Occasionally the bike will idle perfectly and ride without the sound etc.

I've noticed that you all state the the fuel tank should drain when switched to PRI.

I've removed the tank prior to getting the work done and assumed the tank switch was vacume operated???? Is this correct? As my tank will not drain on PRI or RES. When i fix a tub to the vacume line and suck it will drain for a little bit then won't drain at all on both the PRI and RES settings??

Is this normal?? or is this really my problem after all. Should the tank drain with vacume on the PRI setting???? Can someone clarify?

Last edited by MAD13B on Fri Nov 09, 2007 12:04 pm, edited 1 time in total.

Sounds to me like your breather is blocked!? what about if you have it on PRI then remove the fuel cap? if it flows then your breather is definately blocked!

Sounds to me like your breather is blocked!? what about if you have it on PRI then remove the fuel cap? if it flows then your breather is definately blocked!

Will try and clean out the tank in about an hour and will let you know.

I also replaced the fuel filter as there was this rusty crap and build up of stuff in the tank. I blame this dodgy servo i visited just before this all started.

....I also replaced the fuel filter as there was this rusty crap and build up of stuff in the tank. I blame this dodgy servo i visited just before this all started.

Bingo ! that is *almost certainly* the problem........some of this crap has found its way into the carbs, and there is probably a build-up of shite around the internal fuel-tap filter as well.....

If the fuel doesn't flow freely on 'Prime', as DP says, the breather could be blocked. Also, the fuel-tap itself may be full of shite as well, so you should remove this from the tank and give it a good tub as well.............

also makes it worthwhile to change your fuel filter / install one if its absent.

Thanks guys for all your help to date,

Ok update.

Drained the tank, found that the long primary filter stork was loose in the tank so that's all fix. So as a result since it's been loose the tank when on primary has been draining directly from the bottom without a intank filter. Luckily there was a inline filter inplace so everything was caught.

The tank still dosen't drain on primary only when it's in the middle between pri and res???

Goodnews fixed onething, bad news bike still dosn't run well. It seems tempermental. It has run beautifully twice since all this. For no explination. Starting to suspect battery/retifier or coils/leads.

Can anyone suggest a way to check the above?

the 'Prime' position is normally with the fuel tap lever pointing straight down. 'Reserve' is with lever pointing forward, and 'On' with lever pointing back. Check which position the fuel flows when engine isn't running. Have you checked the workings of the actual fuel tap itself ? These vacumn taps have 2 hoses from the rear, a large one which runs down to the carbs, and a smaller one which fits on to the inlety manifold. Check these lines, make sure they aren't split or loose. They have to be tight and in good condition.

Check the rubber diaphragm inside the fuel tap. If this is split, it won't pull fuel from the tank. The bike may still run OK on 'prime' position, but no good on the other 2. If this is the case, the diaphragm is rooted.

To check your battery, the simple test is to start the bike and turn the headlight on. Give the bike a rev - does the headlight get a bit brighter ? If it does, the battery and charging system is working. If you have a multitester, run the leads across the battery terminals. At idle, the voltage should be around 12v DC. Any less, the battery is on the way out. Give the bike a rev, the battery voltage should rise to around 13.5 volts, it may go as high as 14. Any higher than 14 then the regulator is on the way out.

These are just simple tests, sometimes you need to dig a lot further into testing alternator leads, rectifier outputs etc, to track down electrical problems.

Coil resistance needs to be checked against the relevant specs in the workshop manual.

omg :Oi thought i was the only person with this problem, im glad u have to to