fuel filter / running rich???

johnl · Post by **johnl** » Thu Sep 06, 2007 6:14 pm

I recently changed the fuel filter. Since then the bike seems to run slightly different. It surges slightly on constant throttle. In neutral on tickover it runs fine but if you try and hold a constant rpm it the rev counter bobs up and down a little, 50-100rpm. The engine seems hotter than it use to be. The rubber nipple covers on the throttle bodies when removed have a small ammount of petrol in them and the spark plugs seem a little sootier than they use to. The noise of the bike is a bit has a bit more 'gurggle' to it. It seems to me the bike may be running richer than before I replaced the fuel filter.

Any ideas before i strip it down this weekend and check my fuel filter plumbing??

bigblackfalco · Post by **bigblackfalco** » Thu Sep 06, 2007 7:13 pm

Did you clean/change the air filter while you were under there?

johnl · Post by **johnl** » Thu Sep 06, 2007 8:50 pm

cleaned the air filter but have bought a new one that shall go on this weekend.

oh the joys of motorcycling

oyster · Post by **oyster** » Tue Sep 11, 2007 6:52 am

Now try balancing the throttle bodies.

johnl · Post by **johnl** » Tue Sep 11, 2007 2:19 pm

i've balanced the throttle bodies having re checked the valve clearences. I removed the new fuel filter at the weekend and all seem present and correct and was replaced. I also put in a new air filter at the weekend. the throttle cable is correctly seated. i'd be surprised if it was plug lead or coil related.

so.....i'm a little puzzled. I might have to take it to a man to plug it into a computer. Anyone know anyone whos not a dealer. I am aware of jap and german, gsshop and the boxerman.

does anyone else have even the slightest fuel in the rubber nipple covers when removed from the throttle bodies?

might i have adjusted the timing slightly when changing the alternater belt? again i think this would be unlikely.

open to ideas

oyster · Post by **oyster** » Tue Sep 11, 2007 5:14 pm

To provide smooth running;
clean air filter; reset valves; good plugs; check cable free play; balance throttle bodies + tickover. Check all inlet joints are secure. Before firing up, leave ignition on for ten seconds, then slowly fully open throttle, let go, then start.
Alt belt does not affect timing.

bigblackfalco · Post by **bigblackfalco** » Tue Sep 11, 2007 5:36 pm

The other option is that the O2 sniffer has gone tits ooop.
This would give you richer running at idle to 2K rpm.
I wouldn't worry about the fuel in the vacuum caps.

nab 301 · Post by **nab 301** » Tue Sep 11, 2007 7:56 pm

johnl wrote:does anyone else have even the slightest fuel in the rubber nipple covers when removed from the throttle bodies?

Since I bought my bike s/hand 4 yrs ago......

johnl · Post by **johnl** » Tue Sep 11, 2007 8:45 pm

cheers guys.

new air filter and plugs are in. valve clearence and throttle bodies are done.

i'll check for any play in the cable and twist the throttle on on start up.

the bike is'nt massively rough, just not as mooth as it was.

could a flat'ish battery cause any probs?. It could do with a top up of water but aint desperate.