Kawi2strokes.com Forum

I just noticed recently that the longest oil line from the pump to the cylinder base is smaller diameter than the other two. Is this correct? The holes in the banjo fittings are all the same but the line is smaller. This is on a 1974 H1. Also I noticed on a different post about check valves in the oil lines? Not sure about this. Any thoughts? Thanks Dave

There are check valves in the lines integrated into the banjo fittings. The tubes vary in diameter in order to deliver equal oil pressure at the crankcase regardless of the distance away from the pump.

Yes, it's smaller...... I don't remember if you can take out the check valves or not.

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

Z, the flow is low and the lines are relatively large, so there is essentially no pressure drop in the lines. I think the long line has a smaller ID so that it doesn't take as long to fill as it would if it were the same ID as the shorter lines.

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If it surges, that's normal, upshift.

But it's always full, right?

To clarify 'Moo's comment:

The oil lines on the later 500s are made in a way that it is not possible to open the check valves for servicing. The early style can be disassembled serviced and re-assembled. The check valves must function properly and the lines must be full of oil at all times....

J

Z, I assumed that the Kaw engineers didn't like the left cylinder taking a long time to fill when first starting after the initial build or a rebuild, so they made the ID smaller. Just a guess though. If it were to counteract pressure drop, a long one would have a larger ID than a short one. But being a positive displacement pump, the flows will be equal even if the pressures at the pump end are not.

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If it surges, that's normal, upshift.

Makes sense about the time to fill the longer line. I would think you can blow through the check valves to assure that they are seating? Thanks

Yes, you can blow thru them to check them out but remember you must test by blowing both directions.... I was never very good using that technique.

Note: All triples, even 500's don't have a smaller line for the LH cyl.

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Answers are here: http://kawatriple.com/

There have been reports of damaging the check valves using typical "shop" compressed air. As such be sure you turn the air pressure down to around 5 psi before testing.

J