[Ropp]

Could you send us a picture of the underneath of your tank with the Petcock attached to the tank Josep?

 

[WFO-KZ]

Can anyone explain why a bike like this one with a carb, needs an electric fuel pump?

 

[WFO-KZ]

Josep, can you post your VIN so we can be sure of which model we are dealing with?

 

[Ropp]

Yeh, know what your saying matey, probably with having no vacuum in the petcock they use the Fuel Pump to hold back the flow, at least that's how I see it

 

[WFO-KZ]

Yes I appreciate that Ropp, but there has to be another reason. A fuel pump would cost more than the addition of vacuum function to a petcock.

 

[Ropp]

Same with the Early Honda 900rr's some guy's took off the fuel pump and just relied on gravity feed

 

[WFO-KZ]

Perhaps that is what happened here. From what I can determine, the OEM setup was as follows:
Hose from petcock goes to fuel filter and from there it goes to fuel pump which is located under the seat, close to the fuel tank. From the pump it goes to the carb. But Josep says it goes straight from petcock to carb so filter and pump have both been bypassed. At least that is what it looks like to me.

 

[WFO-KZ]

But I still shudder at the thought of the tiny little carb float valve that has to resist the pressure of the fuel pump.
It makes no sense to me. Gravity is 100% reliable, it never fails, it consumes no power and it is FREE. Fuel pumps do fail, they consume power and they cost a lot. So why replace a free system that has worked well for over a century?

 

[Ropp]

Just wondering if Josep has attached the Fuel line to the Vacuum pipe on the Carb, it would fire initially but then start backfiring as too much fuel is getting in

 

[WFO-KZ]

Anything is possible. I also think that unless he has a California bike, one of those ports is for the carb vent and should only have a short piece of hose attached, which is open to the atmosphere.

Also, I figured out the reason for the fuel pump. Due to the V-twin config, the carb ends up being mounted at about the same level or higher than the petcock. Gravity feed would only work with lots of fuel. So to make full use of the capacity of the fuel tank, they added a fuel pump which is mounted high up and underneath the fuel tank. Early I said it was behind the tank, but I was looking at pictures of the dual carb VN1500's. My bad.

The other thing is that this carb has an accelerator pump that will squirt extra gas every time you blip the throttle. Is this the "leaking gas" that Josep is witnessing?

Ok, I gotta go work on some of my own projects for a change. 😁

 

[Josep]

Is just like the third one black / red
..i had it running for a bit and fiel comes out of the vaccum hose that connects to the tank

Fuel

Could you send us a picture of the underneath of your tank with the Petcock attached to the tank Josep?

Thank you guys i been at work all day

 

[Ropp]

Morning all, daft question @Josep has your bike got one carb or two carbs

 

[GREENISBEST]

I'll add only one comment to this thread otherwise this will get even more confusing.
Josep, Please post your Bikes Vin so these Guys can nail the Model to help you out Man

 

[Josep]

Morning all, daft question @Josep has your bike got one carb or two carbs

Single carb

Morning all, daft question @Josep has your bike got one carb or two carbs

One carb
Single

 

[Ropp]

Right matey , then its not a 96 , must be at least a 98 did you get the VIN number to check

 

[Josep]

Tittle says 96 kawk vsd mc
Jkvbnad15ta046170

 

[Josep]

This is it

 

[WFO-KZ]

I think your V and B are reversed. If you flip them it decodes to a 1996. Ah I see another post just came in showing the correct order so it is indeed a 1996 according to decoders.

 

[Ropp]

I'm totally at a loss as my workshop manual shows 96 with 2 carbs , will leave you guy's to this

 

[Josep]

I'm totally at a loss as my workshop manual shows 96 with 2 carbs , will leave you guy's to this

I'm totally at a loss as my workshop manual shows 96 with 2 carbs , will leave you guy's to this

Thank you for yor help