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[vince]

Hi, at 65 mph on standard gearing you turning 4200rpm. Vince

[Adrian]

I don't know why the factory even went up to the 18T sprocket for the Electra-X when 17T was the normal, unless it was part of the economy/emissions angle? As for the whole 19T thing, our hosts are to blame for this!

https://accessories.hitchcocksmotorcycl ... -X-Stage-1

A benefit is also to be gained by fitting a 19t gearbox sprocket.

MAYBE on a well-sorted Electra-X bored out to 535 with a suitably proportioned rider...

Ref fuel/petrol taps, petcocks, or whatever, if the hole in the tap when fully open is larger than the one in your carburettor's main jet, the petrol flows freely with no obstructions anywhere in the fuel system (that includes the petrol tank breather), you're winning, surely?

A.

[PeteF]

Ref fuel/petrol taps, petcocks, or whatever, if the hole in the tap when fully open is larger than the one in your carburettor's main jet, the petrol flows freely with no obstructions anywhere in the fuel system (that includes the petrol tank breather), you're winning, surely?

A.
[/quote]

Not necessarily.
Fuel is being sucked up that main jet by vacuum whereas it's only gravity feed from the tank to the carb.
That could make a difference??

[jawa-enfield]

I had severe fuel flwo problems with a jawa 350.. comparing the petcock hole wirth the main jet does not work..

[Adrian]

That would be the size of the hole on the INSIDE of the petcock. If a sealing washer or something is clogging it you'll never get the full flow.

As for your Bullet, I suggest you remove the adapter from the tank to expose the ¼" BSP thread and fit something decent.

A.

[stinkwheel]

Pobbling along at ~2000rpm or ~55kph, I use less than 2litres/hour or 30-35ml/minute which equates to 80-90mpg.
On a normal ride, with freeway cruising at 1/3 throttle at ~100kph, I get 18-19kms/litre or ~55mpg.
I know at WOT at over 130kph (80+mph) I get far less than that. I haven’t had the courage to hold that speed for long enough to confirm this, but I’d bet it could be 6-8kms/litre.
Putting those numbers together, at WOT it would take way less than 3-4 minutes to use a litre or 250-330mls/minute. The OEM indian tap managed 180ml/min after drilling out.
I also noted that the glass bowl filter (PN 90007) froths like mad at high revs, so reducing the available flow – hence its removal.
I have one of Mr H’s hexagonal taps with reserve (PN 36583) which delivers better flow than I need (actually measured at 420mls/min) but only after I had drilled out the tap bore and sliding plate by ~1mm and installed nitrile seals!
Cheers, ChrisD

I really appreciate that you put actual numbers on this. I was even considering fitting a fuel pump to my 612 bullet but you gives a rough idea of an aim point for fuel flow, obviously if it can be achieved with the tap and gravity, that's one less bit of complexity.

[nab301]

If measuring fuel flow would it not be better to measure it through the float valve? I know the standard Mikarb on my Bullet 65 was flowing less than the petrol tap... ...although it wasn't the cause of the problem on my unmodified bike.

[Wheaters]

The carb body of my 350’s VM24 was badly finished; there was a piece of metal from the screw threads sitting under the screw in float valve.

Every time I used full throttle the float chamber emptied after about twenty seconds and the engine cut out.