Suzuki 2 Strokes

I have cleaned and checked over the oil lines on my 1970 Suzuki T250-II and I have tested both lines which have provided the following pressure readings. The right hand side oil line top check valve opens at 5.5 psi and the bottom check valve opens at 4.5 psi. The left hand side oil line top check valve opens at 5 psi and the bottom check valve opens at 5.5 psi.

Because of the readings are different, you need to provide at least 6 to 6.5psi to both sets of oil lines for all the check valves on each oil line to start to leak oil. Under normal running conditions, will the oil pump provide 6 to 6.5 psi or will the oil pump only provide enough pressure to open the check valves that start to leak oil at the lower pressure of between 5 to 5.5 psi which means 1-2 of the other check valves will not open?

Also, does anyone know if you can get a set of replacement check valve springs for the early model Suzuki check valves which can be disassembled

The easiest way for you to answer the question is to spin the oil pump with an electric drill and see if it pumps equally on all channels. A variation in crack pressure for check valves is not unexpected. Do you have a reason to suspect the oil system? If not, it was likely working fine before.

If necessary, you can replace with modern in-line check valves though you will need to make up adapters/new oil lines.

Keith

Thanks. I am sure the oil pump is fine, however I am just concerned that the oil pump will deliver oil to the check valves with the lowest opening pressures and not the other two check valves which require a slightly higher opening pressure.

You can measure how much oil you get out of each line when you spin the pump. I suspect you will find that the differences in crack pressure will make little/no difference.

Keith

Thanks for your help Keith