Intermittent fault

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

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 outand fill up with fresh.If it doesnt happen again all is sorted.

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.?

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

Originally Posted by 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.?

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

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

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.