Fuel Tank Question - K1 SVS

[fizzwheel]

OK I've been having problems with my airbox filling up with petrol.. I decided that I'd remove the fuel tank and take the carbs apart to clean them.

I've removed my fuel tank before and I dont remember having the situation that I've got now. Basically when I remove one of the hoses from the bike. Fuel starts p*ssing out everywhere from the hose. Now I thought the SV had a vacum fuel tap ? I distinctly remember the last tiime I removed the fuel tank that I didnt get fuel running out of this hose.

I've taken a couple of pictures and highlighted where the fuel is coming from that I think it shouldnt.

I've now drained the tank completely and run the bike so that the carb bowls are empty. My thinking is that my problems are being caused by the fuel tap being stuck open which is slowly flooding the float bowls overnight which is then backfilling the airbox.

If somebody could advise or confirm my thinking that would be great.

Pic's, the pipe in question is highlighted with a red arrow.





Thanks

Fizz

[TSM]

Have you removed the small vac pipe from the fuel tap? There is always an ammount of fuel that will drain out from the pipe you are indicating, not sure how much you have running out though before it stops. Try removing both pipes from the fuel tap itself, if it keep running out then you probably have a stuffed valve.

[fizzwheel]

I drained approx 10 litres of fuel out of that pipe... I removed the other pipe from the fuel tap and it was still coming out of the pipe I have arrowed in the picture.

I think my fuel tap is broken. Thanks TSM.

does sound like the fueltap is goosed, but that doesn't change the fact that the floats should seal off. Bikes with a standard fueltap (not vacuum operated) can be left on with no problem. It is only when the floats get weak do they ever weep.

All that said, there is no question that if there is no vacuum then fuel should stop flowing. It might be a sticking diaphragm, take it apart and have a looksee!!

Oh and when the engine isn't running, the fuel pump will prevent flow to the carbs anyway.

did you strip the carbs?

[fizzwheel]

No I did'nt strip the carbs. I thought Id sort this out first. I'm going to take the fuel tap apart tomorrow and see what state the diaphram is in. The haynes manual also says theres a strainer in the fuel tap to filter out any gunk. I'm wandering if that might be blocked.

If everything appears to be OK with the fuel tap then I'm going to strip the carbs.

Originally Posted by fizzwheel

No I did'nt strip the carbs. I thought Id sort this out first. I'm going to take the fuel tap apart tomorrow and see what state the diaphram is in. The haynes manual also says theres a strainer in the fuel tap to filter out any gunk. I'm wandering if that might be blocked.

If everything appears to be OK with the fuel tap then I'm going to strip the carbs.

The diaphram doesn't actually make the seal (as such) ... a damaged diaphram would mean the fuel would NOT flow even with the engine running/turning over ... There is a little spring that forces the diaphragm closed. There is a seal in the middle of the diaphragm that actually does the sealing (the diaphram/vacuum overcomes the spring pressure allowing the seal to move away from the orifice). So if you see what I mean, if the diaphragm is torn, as long as the middle bit is OK you should still get a seal ... (and you would be getting no flow ).

As for the filter ... again, if this was blocked you would get NO fuel ... not too much of it

Its more likely that something has jammed (in the open position) or some muck has got in there???

Indeed attack this first and it needs to be done anyway, you might get lucky, but I think this might be a red Herring to the overall problem?...

Let us know how you get on.

Either way you need to have it apart

Your problem is plain to see........






























Your SV is yellow, should've bought a blue one

YELLOW = Fastest, Coolest, Bestest, Etc Etc