Few Problems :/

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MAR5H7
Posts: 7
Joined: Tue Feb 28, 2012 7:29 pm
My Bike: ZXR 400

Help - ZXR 400 worrying issue

Post by MAR5H7 »

Ok, its a N reg, UK model, L5

The previous owners didnt look after her much obviously....
So iv made the effort in restoring her myself, which so far has been quite successful as now she runs pretty nicely.. until it rains

Now I really dont know what its to do with so ill explain it as best as possible,
As soon as it rains (has to be coming down moderately) whether I increase the throttle or not, it doesnt matter, it will start to vibrate hard, seeming like its not mixing properly and become incredibly sluggish, then at 6k revs, itll start to be unpredictable as in it will start to jolt trying to speed up then stopping in a second while in not even increasing the throttle

Some have said it could be an electrical fault with water but not too sure
Getting more familiar with these bikes but all the help I can get will be MUCH appreciated

Cheers :)
MAR5H7
Posts: 7
Joined: Tue Feb 28, 2012 7:29 pm
My Bike: ZXR 400

Few Problems :/

Post by MAR5H7 »

Lazy, done a bit of searching but couldnt find anything :/

Ok heres the plot
ZXR warming up, 1.5k revs, beautiful
gets warm and touch the throttle, 3-4k revvs idle from there and WILL NOT DROP
air leak is possible, I ran her with the air box off with a pair of tights clamped onto the carbs and even warm, she reved and dropped beautifully
Put the air box back on, back to square one, am I correct in thinking the air box is crap, baring in mind it also has an annoying K & N filter which Iv seen a few posts that they are a pile of rubbish for some bikes

Then the other problem
It runs fine in dry conditions
A bit of rain and then it becomes toad, vibrates back whether I pull on the throttle or going it steadily and then becomes unpredictable at 6k revs as in it will start to pull normally then back to crap n pull n again then back to crap, all in a few seconds but continuously :/
and then as soon as I pull up to a set of lights, if I dont revv the bike a little, she will cut out and refuse to start for about 20 minutes, then after she will be fine again.... until the rain gets in again
Oh, and the exhaust also sounds very much like a wet fart when this happens D:

Cheers fellas
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RedexRobB
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Posts: 7212
Joined: Fri Aug 30, 2002 7:37 pm
My Bike: ZXR400L3
Location: Ipswich, Suffolk

Re: Few Problems :/

Post by RedexRobB »

For your 'rain' problem, it could well be electrical. You sound like you can work on a bike having tidied it up, so get all the connector blocks apart and check they are clean and theres no water ingress. Also check the loom for any chaffing and that any cables havent been exposed.

If thats all ok, then could be worth checking the HT leads/ignition coild are sound and theres no water getting down in the plug wells, it should drain out if there is as there are holes specifically for this, but could be blocked. Check the battery terminals are clean as well as the earths, one in front of the rear shock and one on top of the gearbox. Tank removal eases access.

As for revs, that does sound like an air leak, and could well be to do with the inlet rubbers letting air in. You can check this by having the bike running and spraying carb cleaner round the inlets, if the revs change then they need looking at. Also check the seating of the airbox where it fits on the carbs.
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