Intermittent fault

[cyphertheory]

Hey All

I recently have had a fault that has appeared twice and then gone away. the symptoms are that after the bike has been run over a distance of say 50-60 miles it starts to loose power, and feels like its not firing on one of the cylinders every few seconds.

it was a dry day and had been for the few days previously. at the time this happened i was on an A road doing 70 in 6th gear. then when I pulled over and let the bike rest for a few minutes it was fine for another mile or two and then the problem happend again. i got back into town and the bike would constantly cut out at the lights unless the revs were kept up above 2k rpm.

the next day i checked the spark plugs for wear and sooting, checked the HT leads were not nicked or broken, no water had got into them and put them back on tight. i checked the motion of the FI parts and lubed them and the throttle cables.

ive not had the problem since, but im worried about it reoccuring again if i got on a longish run

anyone have any ideas that they could throw in as to the possible fault?

thanks

Paul

[sixstring]

Hi Paul, nice to know there's another Beckenham boy here! Your problem sounds like a post I was reading the other day - could be a blocked breather to your petrol tank. As your bike uses fuel it causes a vaccuum that stops the fuel getting to the engine. you could try taking off the fuel cap and cleaning it..... DON'T DROP ANY SCREWS INTO THE TANK!!!!!! They're a b**ger to get back out

[Biker Biggles]

Two suggestions.
Carb icing is like that but yours is a pointy?
Water or other crap in fuel would do that.Run fuel low,without running out:Dand fill up with fresh.If it doesnt happen again all is sorted.

[cyphertheory]

hey Sixstring! ill be looking into that hopefully its something nice and simple. good to see more beckenham sv'ers. you near the high st.?

[cyphertheory]

yeah i got a pointy, sorry should have said that.

water in the fuel certainly is a possiblilty, and would explain why it is intermittent. ive gone through the fuel that was in the tank when it happened, and not had the problem since

thanks biggles

[sixstring]

hey Sixstring! ill be looking into that hopefully its something nice and simple. good to see more beckenham sv'ers. you near the high st.?


I'm near Bromley High St - Black curvy with Givi rack. What's your pointy like?

[cyphertheory]

its a custom colour metallic grey (taken from a new transit no less!) pretty standard apart from that and the 14" long carbon stubby!

next time i see a black curvy ill give it a toot lol

[St0rmer66]

When I had this problem on a carbed bike it turned out to be a bit of water in the fuel. Just emptied the carbs and it worked fine after that. So I assume it would be similar on a FI bike.