Carb Problems

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erebus
Posts: 2
Joined: Sun Jan 29, 2012 7:06 pm
My Bike: ZX 400 G 1988

Carb Problems

Post by erebus »

I have a 1988 ZX400G (very similar to the ZXR I am told) which i need your help and advise.

Long story but, better I explain the timeline and problems i have had. Brought this bike of Ebay a few months back and rode it 200 miles home which was great fun, ran like a dream!!!!. Over next few days it rained and i found out that the fuel cap rubber was missing and i had water in the fuel tank, The bike bogged down at anythng more than 1/4 throttle and struggled to get above 6000revs, I emptied the tank completly and replaced with fresh fuel, i then noticed a small and slight fuel leak dripping from the rear suspension. culpret was the Fuel filter was cracked and bent. Replaced this with a new one but the bike would start after this. after some scratching of heads, I replaced the fuel pump and blew out all the fuel pipes. but bike would stil not start, but if i sprayed cold start down carbs, the bike would roar into life!!!. so definatly fuel based problem. I noticed that there were 2 small rubber pipes coming from under the carbs near the spark plugs and decided to blow through them and the carbs spat a load of water/fuel in the air from what i guess was the carb bowls. after doing this for a few minutes. I tried to start the bike again and it started first time. But stil bogs down after 1/2 turn of throttle and struggles to rev at all. sprayed a load of carb cleaner in the carbs and ran the bike for a week and the performance slowly came back to what it used to be but stil ran rough. but in the last week its then got worse again. The bike started to backfire and does not like to rev or idle below 4000 revs. But if i full throttle now after 4000 revs. the bike flys like it used too... SO very confused, I have checked and no water in fuel and have blown through the pipes again to see if this would help.no joy so any ideas anyone? HELP!!!!

Andrew
ZX4R-F3
Posts: 95
Joined: Thu Jan 13, 2011 1:03 am
My Bike: 1988 ZX400-F3
Location: Ashton-u-Lyne

Re: Carb Problems

Post by ZX4R-F3 »

strip, clean and re-build carbs, spark plugs remove clean check gap replace if necessary, air filter check/replace, HT leads cheap to replace. check and reset pilot screw to factory setting. Get stuck in, get your hands dirty.
[b][color=#FF0000]If your not living on the edge, then your taking up to much room.[/color][/b]
erebus
Posts: 2
Joined: Sun Jan 29, 2012 7:06 pm
My Bike: ZX 400 G 1988

Re: Carb Problems

Post by erebus »

Never stripped a Carb before and a little worried I would truly Bugger it up. Is there any guides on here for that carb? photo's preferred if anyone has them? :gamer
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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: Carb Problems

Post by RedexRobB »

If it were me, first things first, get a rubber seal for the fuel cap, no point in going through anything and trying to get rid of water if you dont solve the cause! then blow and clean everything out that you can.

To save you stripping the carbs, have you tried draining them first? There little allen drain screws, give them a twist and catch the fuel that comes out. Also might be worth taking the rubber bung out of the pipe that runs out of the airbox, this fills with water this time of year through condensation. See if that helps too.

After all that, run a shot of Redex through in a full tank of fuel, that should sort things out nicely.
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