Kawi2strokes.com Forum

Pretty much a garden hose... 3/8" NPT into the tank

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http://kawatriple.com/wtf/

Thanks Nev, your scenario it exactly what I was worried about.
And now my petcock has stopped leaking (it sure helps to assemle it the right way) so I'm ready to do a test pretty much like one you described.

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Peter says:
Keep the revs up !

Bikes:
H1 Candy Red, 1970
Moto Guzzi Daytona 1000, 1992

Ok - as mentioned earlier, I managed to assemble the petcock correct in only 3 attempts
It's now completely tight, so today I did a test, where I set the lever to "PRI" at let it fill a container with 250 ccm, and measured the elapse time. I did 3 attempts, and the average time was approx. 20 sec.

As i wanted to come as possible to real life circumstances, I left the fuel cap on the tank, securely tightend, and I mounted some fuel lines with the type of external filter I intend to use. For information, there are also 2 filters on the petcock - plus the strainer.
Perhaps overkill ??

I made the assumption that petcock performance is the same, regardless of lever is in "ON" or "PRI" position. ( I had no way of creating vacuum)

The conlusion is that it delivered slightly less than twice the amount needed when running WOT.[/b]

I came to this from interpreting this chart:

... where I pay specific attention to the Fuel consumption graph which is measured in grams pr. horsepower pr. hour.

7.500 rev/min (max Hp perfomance) consumption can be seen to be approx. 300 grams / hp / hour or 18.000 grams /60 Hp / hour.

So with the knowledge that Gasoline (EN 228) weighs about 720-755 grams (at 68 deg. Fahrenheit) the petcock performance can be translated to: 540 grams /minute (because 250 ccm = 1 Litre in 80 secs = 720 grams in 80 secs)

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Peter says:
Keep the revs up !

Bikes:
H1 Candy Red, 1970
Moto Guzzi Daytona 1000, 1992

It should be about the same, but you can put a tube on the vacuum port and suck gently on it with your mouth. It doesn't take much to make it open.

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If it surges, that's normal, upshift.

Thanks Jim - tank still sits in rack, so maybe I should give it try. Before eating my meal

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Peter says:
Keep the revs up !

Bikes:
H1 Candy Red, 1970
Moto Guzzi Daytona 1000, 1992

If gasoline comes out of the tube, the petcock has serious problems. Use clear tubing if you're not sure of the diaphragm's condition.

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If it surges, that's normal, upshift.

So you got 750cc/minute? Is the bike dead stock? I have not worked on a stock 500 forever, but it sounds a bit less than I would like. A RD250LC will run out the bowls with 450cc/minute at WOT for about one mile in US distance. I am a wee bit dubious about the little graph from the manual . Sorry. I am trying to help, not frustrate you. I should hate to see a problem. Maybe remove your filters and check again??

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I am just a man working in a tin shed.

Thanks Neville, your'e not frustrating me at all. We are all on the same mission here: Learning and sharing

Yep 750 cc/minute was what I got with lever in "PRI" position. This equals emptying a full tank in 20 mins.
Your'e right about the chart, but it's what I have, and I think it's an official Kawasaki chart, not something compiled by a Danish magazine.
Your point regarding the filters is very relevant, so I will repeat the test without the filters...

One of the things that causes uncertainty here, IMO, is that we don't know the consumption with WOT, but if we assume that WOT equals 60 hp, and that bikes top speed is actually reached at 7.500 rev/min (might be correct with 16T / 45T F/R instead of 15T / 45T) bike will be able to cover like 195 kms/3 (20 mins = 1/3 hour) or approx. 65 km. This equals an avg. consumption around 4,3 km/litre, provided you are able to run the tank bone-dry. Not too unrealistic, I think. But very theoretical

Any which way: The engine will have melted away, long before the 20 mins. And I don't intend to run it for more like say 1 minute on WOT

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Peter says:
Keep the revs up !

Bikes:
H1 Candy Red, 1970
Moto Guzzi Daytona 1000, 1992

According to your picture in the other thread, you have the filters installed backwards. I don't think it makes a big difference though.

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........

Say you are getting a dismal 10mpg, and you are doing 120 mph for 1 minute. That's 2 miles in a minute. So you are looking at 2 miles at 10mpg, or 1/5th of a gallon. There are 3785.41 cc's in a gallon, so 1/5th of 3785 is 757cc's.

Just the math of it all........

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........