Solo to Sidecar by STD

[Nortonist 592]

Once the fuel pump is shut off (if there is a fire) fuel can't flow so there really is no need to firesleeve the line between the pump and the carb.  I approx. 6" of unvalved fuelline between the tank and the pump.  Its firesleeved but not the rest to the carb and the return line.

[Bruin]

What do cars use for metal lines, aluminum?

[Bruin]

Static fuel pump beta test done. Cobbled together enough hose to complete the fuel line circuit. Triggered the Hi Beam switch and gas flowed like second hand beer.  Best of all, the carb needle valve was not over powered... so no overflow. Doing the happy dance.

[Koncretekid]

Bruin,
What kind of a fuel pump are you using?
Tom

[Bruin]

I mounted a "ACD 6v electric fuel pump" from Jacksons Old Time Parts. It is 10 amp 5-8 psi.

I do have a second choice, a "Mr Gasket Micro pump" 12v from O'Rileys.

Whatever unit I use will have to run off its own battery as I want to save all the generated juice for the CDI ignition. That may be false logic but it makes sense to my uninformed noggin.

[Nortonist 592]

Whatever unit I use will have to run off its own battery as I want to save all the generated juice for the CDI ignition. That may be false logic but it makes sense to my uninformed noggin.

Definitely not false logic Bruin.  Up to this year I ran a big car battery in the sidecar.  It powered the ignition and fuel pump.  Never had to give it a thought.  This year I changed the sidecar to an alloy wheel and different platform (another story).  The change meant I had to move the battery and fuel tank inside the frame.  Smaller tank and battery.  Running on a 121 record the first run was 125 for the mile 129 at the quarter.   Off to impound.  Do the usual checks.  Come back in the morning.  Return run, 115 for the mile.  Miss the record by less than 1 mph. 

Spent the week chasing our tails.  Eventually we upped the record by 1/2 mph.  But I slowly chased the cause of our slowness down to the battery and a voltage drop that restricted the rpm.  This year I'm going back to a big car battery to get rid of that problem.  If you are going to run small(ish) batteries definitely run two.

[Bruin]

Since I already have one on hand, I'm thinking about swapping the 6v for the 12v. The 12v produces lower psi of 4-7 but plenty of flow at 35 g/hr. But mostly, at 12 v, there is a great supply/choice of batteries at hand and they can be charged off the car if needed.

(I'm assuming the 6v and 12v won't have a measurable difference in battery/life, that will be more dependent on the batteries themselves?)

[Bruin]

Here is the pump fuel line diagram with a pressure reducer and the 12 v pump instead of the 6 v. The net said it only pulls one amp. Does anyone know how low a battery can drop in volts and still power such a pump?

[Old Scrambler]

Brian...........I used a 1.5-amp charger in the hotel-room to keep my batteries charged. Remember to plumb the On-OFF for the pump through the safety-switch tied to your wrist.  Nice work. Good idea on the separate battery.

[Koncretekid]

I'm not an expert on batteries, but if you have a 6 amp hour battery, it should last about 6 hours producing 1 amp, but will it still have 12 volts?  One sure way to tell, hook it up and let it run for an hour, or even just 15 minutes (more time than you'll need for a couple of runs).  Check your voltage while it is running to confirm your suspicions.

[Bruin]

I've got a trickle charger so I can top off the battery overnight. Is wiring the pump through the kill-disconnect switch just a good idea or a rule? The way I thought the BUB rules read was that the fuel (pump) had to have a cut-off switch on the handlebar. That I do have. Right now the disconnect kills the ignition by grounding it out. I'm not sure how I would piggyback a completely separate electrical system onto it.

I will do a timed pump run to test the amp usage next time I can stand the temp in the garage. An artic front just arrived, it is 34 degrees and dropping like a stone right now.

[Nortonist 592]

Looking at the SCTA rule book, rule 7.B.2.3 says "If the ignition kill lanyard does not shut off the fuel pump, the motorcycle shall be equipped with a tether type shut-off device attached to the vehicle and the rider so the fuel pump is shut off if the rider becomes separated from the motorcycle".   Reading that it would seem, for the SCTA at least, you would need to wire the fuel pump into the kill switch.

[Bruin]

"BUB 2.E. Gasoline class motorcycles shall have a fuel shut-off located within easy reach of the rider. Fuel class motorcycles shall have a positive fuel shut-off activated without the riders hand leaving the handlebars. In gas and fuel classes a lanyard must connect the ignition shut-off switch to the rider."

So I'm thinking my pump on-off switch on the handlebars will meet the BUB requirements.  (And simplify the wiring in a self contained pump system.)

[Nortonist 592]

Yup.  Looks like you are dead legal for BUB.  I'd still prefer the fuel pump shut off to be tied to the deadman.  But its your machine and I'm in the grandstand eagerly waiting to see the final outcome.   

[Bruin]

With the ignition and pump on two different systems, and not sharing a common ground or power, it would take two disconnect switches.

The previous pump test was on the 6 v. When I tried the 12 v pump nothing happened. The replacement battery tested only 10 v so I charged it over night and today the pump purred with a full 12 v charge. All that is left to complete the tank relocation and pump instillation is the trim the wires and hose to size, and fire sleeve 'em.