Hi all I have been talking online with a chap on another site about starting issues and carburettor cleanliness he mentioned in relation to fuel pipe rooting that he had installed a low pressure fuel pump to his bike and it had really helped with the starting issues does anybody have any experience of this either good or bad please
Hi i have installed fuel pump on my bike, because of the vapourlock of the fuel line. Scotch have invented solution against it using different approach but for me was the pump. One thing tho if you got the pump you need also preasure reducer, other wise preasure may overcome the float valve ability causing overrich problems. Hoever I made probably 3-4 k kilometers with this setup never havins a single problem. For more info just ask.
All a fuel pump will do is fill the bowls faster (?) It has nothing to do with making the bike start easier because - once the bowls are filled the float valve shut's off the fuel. The pump does not prime the fuel circuits. Getting the fuel galleries (All above bowl-fuel level) filled is done strictly by engine vacuum. Modifying the Choke-Air port (under the main-jet diaphragm) significantly improves starting by increasing the vacuum under the choke plunger which in turn draws adequate fuel to the choke circuit. If the concern is "Vapor'lock", then there's an issue regarding the size of fuel line and/or how its' routed - which is easily remedied.
Search here for "Choke Air mod" & "Fuel-Line routing".
1980 KZ 1300 sr# KZT30A-009997
Always High - Know Fear !
In addition, I've got my fuel line run the "stock" way (out the tank, down in between the 2d and 3rd intakes, curved down into the fuel solenoid valve, then straight up into the carbs). The only issue I've noticed is that it's a BIT hard to start on longer layups (more than a week without riding), but apart from that nothing that's affected normal operations.
Everybody had their own opinions on fuel line routing and fuel pump usage, so here's one more- personally, I don't think it'll hurt to run one, but at best they are unnecessary on a proper setup, and at worst can be a band-aid solution covering up some more fundamental carb issues. But, of course, your mileage may vary.
If you are going to fit a pump, its essential the pump comes off a bike with conventional carbs fitted, so the pressure is suitable for carbs.
The ones I have used are from a Vmax 1200 as they have normal float bowls and float valves.
By memory I think its a Mitsubishi made pump AND VERY LOW PRESSURE...............so no regulators fitted.
The pressure from this pump is the perfect level for our 1300 carbs.
you can hear the pump ticking until the bowls are full, then it stops until more fuel is used.