running problem - as if running out of petrol
 

Hi,

I have been having a bit of problem with my bike. It has been running with really low revs an is really jerky as if it is running out of petrol but there is plenty petrol in. The engine sounds really rough and is shaking alot. I had to have the throttle open quite far and every so often it will suddenly go back to normal and because i had the throttle open far it would suddenly shoot off. Then the revs would drop back down again and would die if i didnt keep the revs up.

I have got no idea what is wrong. at first i thought it could be out of oil but there is loads of oil. When this happened it was raining quite heavily so i thought that might have something to do with it but it is dry now and it still has the problem.

Thats all my ideas so if anyone could tell me what the problem could be and if i can fix it fairly simply as i dont have much knowledge about bikes that would be great!

Re: running problem - as if running out of petrol
 

im having a similar problem at the mo pal, dont know wat it is yet sorry but when i find out i'll be able to give you a heads up to what it could possibly be

Re: running problem - as if running out of petrol
 

sounds like a trapped vaccum hose, have you had the tank off or poked about under there lately.

or a fuel feed problem

or

Re: running problem - as if running out of petrol
 

....or water in the fuel.

Re: running problem - as if running out of petrol
 

I had a look under when the problem started but not for a while before the probelm.

Anything i can do if there is water in the fuel? or am i going to have to run it till its dry and refill it?

Re: running problem - as if running out of petrol
 

Make surec that the drain hole under the filler cap is clear so that if it is raining hard water isn't getting into the tank via this blocked drain. Think it's a problem on some curvy's.

Make sure its not the front spark plug getting wet either, as mine was a bit like this before in the wet. Cured with a fenda extender & a bit of silcon grease round the front plug cap. WD40 on the spark plug & make sure the drain on the front cyclinder is clear as well, otherwise the water can't get out

And you could check to make sure that all the vacum & petrol pipes haven't perished and letting a tiny amount of air in somewhere. I had a car do this to me once

Do the spark plug first, as this is a common problem on Sv's in the wet for some, but not all

Re: running problem - as if running out of petrol
 

If it was the spark plug would it not work fine when it was dry?

Re: running problem - as if running out of petrol
 

Wet front plug I reckon.

Water takes a while to dissipate.

Re: running problem - as if running out of petrol
 

Not if the drain hole is blocked and the spark plug is still damp. Mine took ages to get back to normal, even though I'd sprayed loads of WD on the plug cap & spark plug

Re: running problem - as if running out of petrol
 

Thanks YC +1