Kawi2strokes.com Forum

Been talking to Jim about replacement check valves; something I had worked on approx 3 years ago with Carlos and Mark in SC. Couldn't find my notes and was fuzzy on the details. Thanks to Jim here is the old thread.

http://www.kawasakitriplesworldwide.com ... =2&t=42264

Since I know next to nothing about fluid dynamics, if the check valve was at either the pump side or inline, would it absolutely keep the oil in the line from flowing into the motor when not in use?
Read the thread first so the question makes sense.
Have a PM into Carlos as well.

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There are only two types of motor sport racing:
Nitro and everything else
(Sometimes referred to as fast and slow)

In my opinion, the lines probably wouldn't drain if the check valves were at the pump end. This could be easily verified, as long as you use lines that are at least as clear as the originals.

I also doubt if it would be a problem if the lines did drain, since that extra oil would be present on startup. I'd use small ID likes like the originals or smaller, so if they did get air in them someday, somehow, they would fill quickly. With the flows and pressures we're talking about, I wouldn't be afraid to use 1/16" ID lines, but anywhere around stock ID would be OK.

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If it surges, that's normal, upshift.

Hey Jim, Seadoo 580 motors put the check valve at the pump. What size are the banjo bolt threads on the kawi pumps?

http://fiche.worldofpowersports.com/wps ... 3&A=2&B=12

#12 $13.50ea.

Don

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Don

They're M6 x 1 Don.

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If it surges, that's normal, upshift.

Yamaha has the valving at the pump.

With the orifii that the oil must pass through at the banjo bolt end, not much transfer would happen if the engine were sitting static, not running, UNLESS there was a check valve problem, AND over pressure in the oil delivery system pressuring oil past the open check valve. This can happen when the oiling delivery system "heats up" and pressure expands past adequate venting.

The hole in the end of the banjo bolt for the crank bearings is less than .015, the one in the early system in the cylinder inlet port is also less than .012.

The line going to the check valve from the pump DOES NOT have to be a hard plastic line, as in Yamaha and some other systems, a good grade of plasticized rubber line is adequate. Only consideration is, the line itself should not be able to expand and contract with the pressure differences of the pump. This is why some systems use the hard plastic lines.

Black lines are better to help alleviate oil degradation from sun light, opaque allows seeing the oil, and any bubbles in the system.

If the valves are placed at the pump outlet, oil shouldn't drain if the level of the end of the line feeding point is above that of the valve outlet in the pump. If the bike is parked for a long time with a sidestand for example I believe there is possibility of draning at the lower points, such as the oil bolts of the case.

For oil injection to carbs bowls that are at a higher level I wouldn't see problems.

For injection to the cases I would preffer having the valves as close as possible to the banjo bolts.

The lines behavior should be as follows:

To the carbs, there is no pressure as the bowls are open to atmosphere. Any good quality hose could be used.

When injection is to the cases circuit, oil is routed through the bolt orifice and as H2R Tuner said it has app. 0,3mm diam, so there will be a pressure increase that has to be taken by the hose; this will also happen with the original design with the valves fitted directly to the banjos in the bolts. For this reason I'd preffer using nylon hoses or other hose types that could withstand a higher pressure. I intend to measure this pressure, but didn't have the time yet.

Jim Crenca, if I had to choose from one of the 3 valves tested, I would use the in line Yamaha valve n° 1 of the test, as close as possible to the banjo bolts and would use them also for the carbs. The spigots are small and you can use small diam. hoses. Maybe you can find a braided line or nylon or similar and make special bracket rings to press in the end of the spigots like the OEM used to be.

The Artic n°3 didn't provide 100% sealing as it is of steel ball construction, sealing to the brass body and not O-ring like the other 2 tested. It may last longer as there is no O-ring aging and hardening, but I didn't trust that valve very much; it also requires some extra room and I'm not sure you can fit all 4 valves in the pump area; I tried fitting it to my H2 and the one at the rear and right of the pump will block the next outlet at left.

I'll post more in the near future on the valves I made for my H2 project. They were made in ss steel and aluminum, using the same concepts of the O-ring valves tested, but for opening pressure of 4,3 psi and with a ss steel banjo for use in the cases. The other 3 I'll mount in the intake manifolds, so instead of banjo I made threaded ends. Unfortunatelly I will not make more of those as they cost to much money and time to make in small scale.

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75KH 500 - 74 H2 special- 74 H2B on restoration

If the release pressure of the ball is set correctly, there will be NO oil migration past the ball/seat/check valve, no matter where the check valve is placed along the oil line from pump to engine inlet point.

This is what Carlos references:

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

YES, check valve "blow off" pressure IS a big concern. The system delivery is balanced to allow a certain volume of oil through the valve at one pressure, 4.60 psi, and when the blow off pressure is lower, the ball is allowed to lift off the seat further, allowing more oil volume to pass through the valve. Usually, "rebuilding" the check valve only requires a new check ball, and to set the blow off pressure by GENTLY and CAREFULLY stretching the spring, checing pressure, stretch, check, etc. I have removed the plastic lines and threaded both the check valve and banjo bodies to allow threaded hose fittings to be applied, that I have made on my lathe, fitting plasticized rubber lines in place of the moulded plastic linrs. I have also used other brand's banjo fittings that already have hose barbs on them on the oil pump ends. Works fine.

Jim C, here is a pic of the valves I made. (can't be offered because of the high manufacturing cost). I'll post more details as I finish the complete oil system, lines, bench testing, etc...

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75KH 500 - 74 H2 special- 74 H2B on restoration