Fuel consumption

[Dash]

I noticed my Hawk`s been drinking a lot lately.
88 miles, then I have to switch to reserve. is that normal or is there some evil time/space vortex or whatever in my tank?

it has a dynokit and an open BSM Carbon can. can that cause this enormous leap in the fuel consumption? it used to do 120 miles before having to switch to reserve...

[SkinnE]

Well, that's what you get when you wear those leathers and run around with the tacho needle in the redline all the time!

You say you switch to reserve, do you go far on reserve lately? I ask because it sounds like your fuel pump isn't working. Without a fuel pump, the Hawk will do approximately 100 miles, then act like it's out of petrol. It's just that the lowest part of the tank is below the float bowls, so it won't drain by gravity alone, therefore Honda put the pump on to get to the bottom of the tank.

You could remove the pump cover and watch for the plunger with the bike running, or try disconnecting the fuel line from the carbs and start the bike. Fuel should squirt out in pulses, then your float bowls will run dry! If you get no action from the pump, try jumpering the pump relay (see the manual for info on this). This relay is expensive to replace, but cheaper than a pump (over 140 euro for a pump)!

Good luck

E

[DefTrap]

What Eric said.
My BSM VAmpired Bros utterly thrashed does 125 miles to reserve consistently.

If you baulk at the cost of a new fuel pump you could try a mechanical vacuum pipe. I've a s/h Divvy one that cost me a fiver, haven't fitted it yet mind.

[hawksonfire]

I still dont understand why yall dont just put it on reserve and leave it there....yes I know some of you dont have odometers but is it that hard to open the tank and look?It will save the petcock and prevent the lines from the temporary stavation which cant be good for the pump

[Abquid]

Sprockets perhaps?

My Hawk also used to hit reserve at 89 every time.

I had bought the bike used and knew it had been used for racing, so I ordered new front and rear sprockets and put them on. Shortly after I noticed that I was now getting to 106 before hitting reserve.

My guess is that the old sprockets were a little extreme (maybe 15/46?) and because my cruising speed was at higher rpm I was getting less mileage. When I ordered the new ones I didn't know this and just ordered the stock models (16/44, I think) and these allowed me to cruise at lower rpm and get correspondingly better mileage.
I could be wrong on this--it may have been pure coincidence. But there's no doubt that my mileage did improve by over 10mpg, whatever the reason.

Of course, the stock ratio might be better if you do a fair amount of commuting/freeway driving, but less good if you want quick off-the-line starts and are want to use the upper end of the power band more, as you might for racing, etc.
But then you're probably not so concerned about mileage anyway.

[Dash]

Damn, if its really the pump I`m screwed
I`ll check that out when I have the time.

But I have been ridinga t high revs lately...

[GTR647]

Damn, if its really the pump I`m screwed
I`ll check that out when I have the time.

But I have been ridinga t high revs lately...

how many liters do there go in when you hit the reserve at 90 miles?

[Dash]

Damn, if its really the pump I`m screwed
I`ll check that out when I have the time.

But I have been ridinga t high revs lately...

how many liters do there go in when you hit the reserve at 90 miles?

all 10.

I checked the pump. it squirts like a horny elephant.
so that`s not it. (thank god)

[hawksonfire]

What was the setup on the bikes' engine when you got 120mpg and the setup now...

[hawksonfire]

not mpg sorry....miles before reserve(mbr lol)

[GTR647]

Damn, if its really the pump I`m screwed
I`ll check that out when I have the time.

But I have been ridinga t high revs lately...

how many liters do there go in when you hit the reserve at 90 miles?

all 10.

I checked the pump. it squirts like a horny elephant.
so that`s not it. (thank god)

maybe you should ride it with less reving

[DefTrap]

Last time my bike did this the choke cables were sticky.

[GTR647]

Last time my bike did this the choke cables were sticky.

good one, maybe their stuck because of your Superbike handlebars, like your throttle cables did when you installed it

[DefTrap]

Last time my bike did this the choke cables were sticky.

good one, maybe their stuck because of your Superbike handlebars, like your throttle cables did when you installed it

I was thinking more of seizing over time. The lower choke cables are almost impossble to lube without removing them from the bike.

[Dash]

Then the idle would be far to high also, right? the idle is just spot on.