2 stroke engine oil pump

 

Does anyone know how much oil the pump on a two stroke engine shut pump,
should it be a dribble or quite a large amount


thanks

simes

 

It'll vary from bike to bike (mostly related to engine displacement), but...
it'll be a virtual trickle even at full throttle.

Check your service manual.  Usually it'll indicate "x" amount at full pump
opening at a given RPM.

 



The specific amount would depend on the bike. For an RZ/RD350 theres a
procedure suposedly otlined in the manual, I have the procedure here
somwhere, but I dont have the manual. but heres what I found...

1. Mix up some 40-1 Pre-Mix, drain out all your fuel and add the pre-mix
to the tank to keep things oiled while you run the tests. 2. With the
engine off and the oil pump cable/pully set to specifications, twist the
throttle to wide open and note where the oil pump pully is at. I put 2
small dots of paint, one on the pully and one on the pump using a
toothpick to mark the full throttle position. 3. Pull on the oil pump
cable sheath where it enters the metal elbow just above the pump. This
will rotate the pump to your marled position and also expose the actuall
cable. I use a pair of hemostats clamped onto the cable to hold the pump
pully at the full throttle position. 4. Disconnect both oil lines at the
carbs and route both oil lines to a small measuring receptical. I use a
VERY small syringe body as it is graduated in CC's and fractions. I also
place a small vacume line between both the oil ports on the carbs to
seal them off for the test. 5. Start the engine and with it at IDLE,
wait till the first bit of oil starts out of the oil lines into the
container. When this happens, start counting pump strokes. The full
throttle/maximum oil output(where you set the pump pully for in step 3)
is between 2.58 - 2.85CC for 200 pump strokes. When you count 200, shut
off the engine and measure the oil in the container. 6. Return the oil
pump cable and pully to the idle position. Clean out your measuring
container and run the test again. This time you are looking for the
minimum oil pump output of 0.12-0.19CC's of oil for 200 pump strokes.

These oil volume figures are from a Yamaha factory shop manual.

If all is well, I remove the jumper line I installed and re-attach the
oil lines to their respective carbs. If it is not correct, shim
accordingly. When done, drain out the premix and add your normal fuel. I
do this test every time I go through a tune-up.





--
1984 RZ350