Fuel blockage?

[scumdog]

One of my mates (yeah, yeah, I DO have mates :bleh: ) has a 1990 Kwaka GPZ500, when it gets low on fuel it coughs and splutters and dies, even when he flick onto 'reserve'.
He tried taking the tap out etc and cleaning things out but still does it and the bike conks out without warning when it is low on fuel.
Last time he had to rin the 14km to work when the Kwak died, to you and I it's not a bad jog but to him it was just an inconvenience :bleh:
Any ideas/theories??

[Bonez]

Hmmm. Sound like the stand off pipe for main is missing or reserve galleries in the tap are block.

[Dr Bob]

I've got a replacement tap on one side of my bike that has a different reserve level than the other. Check to see if the taps are original, it could just be that the reserve is shorter on the tap than on the tank. I have to switch my left hand tap onto prime to get over this.

[F5 Dave]

Tanks breather ‘specially if the tank has had a sealing kit through it. Or if an in-line filter is fitted they often cause a kink in the line.

[vifferman]

Yeah, what F5 Dave said. If it starts running again if he takes the tank cap off, then that points to a blocked breather.

My VTR would run badly (lfuel starvation) when down to the dregs in the tank. Never did get to the bottom of it, but I reckon it was a combination of crud in the tank and a very shallow angle between the tap and the carb bowls.
And no fuel pump.
And very big'n'thirsty carbs.

Oh yeah - on some of those taps, it's easy to reassemble them wrong, so it's not in the position you think it is. He could be on 'Off' when he thinks it's 'Reserve'.

Just grasping at straws here....

[Stevo]

Fuel Pump.

This is an excellent place to start. Mrs had a problem with her ZX9R conking out low on fuel. The pump had shit itself, but when the tank was full there was enough head to keep the fuel flowing but when the fuel was low but not run out there was not enough head.
Had to keep her bike topped right up for the rest of that rally, which was an inconvenience............................. but it beat the shit outta walkin.

Hope that helps, (Esp bein a Kwaka and all as well)
Steve

[scumdog]

Thanks for all the replies guys, I'll get back to my mate with your ideas.
Stevo, I'm not sure if this bike has a fuel pump but I'll have a look.

Get back to y'all later about this once we've had a 'play' with the bike.

[Stevo]

So what have you discovered Scumdog?

[Milky]

Had a similar problem, which we partly fixed by making sure the fuel lines all ran downhill (on a bike without a fuel pump) *might* not be the solution, but it wont hurt to check out the geometry anyway.

[FROSTY]

I had a problem with a gpz900once where the tank cap had been put together with the rubber seal backwards.
The bike would run fine for 10 minutes then stop
Had me headfucked till I turned off the workshop radio--and there was a hissing noise from the tank cap --tell ya mate to try ridin the bike last couple of ks with the cap loose see if it makes a difference.

[scumdog]

So what have you discovered Scumdog?
After reviewing the info from you lot and checking out the fuel tap again it seems to be faulty and allowing fuel past the reserve section so when the bike runs low on fuel and you switch to reserve there is no more fuel.
My mate is just going to put up with it in the meantime and set his tripmeter to '0' each time he fills and keep an eye on the distance he has covered.

Once again, thanks guys.

[Paul in NZ]

After reviewing the info from you lot and checking out the fuel tap again it seems to be faulty and allowing fuel past the reserve section so when the bike runs low on fuel and you switch to reserve there is no more fuel.
My mate is just going to put up with it in the meantime and set his tripmeter to '0' each time he fills and keep an eye on the distance he has covered.

Once again, thanks guys.

Mate... I don't trust any tap, light, fuel indicator thingy or nothing!

Set the trip meter and use your noggin. I'd rather fill a half empty tank than push a totally empty bike..

Paul N

Mind you the Guzzi has a seat like a plank so I like to stop often...

[Bonez]

Mind you the Guzzi has a seat like a plank so I like to stop often... I'm glad someone has confirmed my testride observation I made all those years ago when thinking about replacing the Fc2 ;)

[Stevo]

Always use my trip. 30kms is my absolute limit for running reserve on the Fizzer and that is probably when I'm kind to the go-fast bit......