Topic: Valve Train Oil Lubrication for CB750 K1

[CB750F2]

I have recently removed each of my valve tappet covers in turn to see if there is adequate lubrication for the valve train. Even at idle there is quite a lot of oil spitting out of the exhaust inspection holes. Hoeever, there is no oil being spat out of the intake intake inspection holes even when I rev up the motor. Is this normal?The intake valves and and rockers are wet with oil. I did this inspection with the motor at normal operating temperature. Is it because of the direction of rotation of the camshaft and/or the intake inspection holes are higher than the exhaust inspection holes? Thanks, Pat

[markjenn]

I'd guess the difference is just a random by-product of the design and/or the lower level of the exhaust side which results in a larger pool of oil to splash around on that side.  I doubt you have anything to worry about.

- Mark

[CB750F2]

Thanks Mark. I am not overly concerned but valve train lubrication has been a hot topic lately and this question ahs been asked before and no definite answer was given. I am hoping someone will go and and do the same check that I did and post their results. Pat

[Steve F]

Well, I know for a fact, you shouldn't remove or "forget to put the exhaust covers back on" when the engine is running....what a mess with oil everywhere 

[CB750F2]

Yes. it doesn't take long - 2 to 3 secs -for the oil to start spitting out of the exhaust openings. Not so on the intake side - with my bike anyway. Maybe I didn't wait long enough for the oil to get to the intake rockers. Pat

[bwaller]

There are two outlet holes from the pressurized oil galleries in the cam towers under each intake rocker which direct the spray toward the exhaust side (although obviously everything gets splashed)

[CB750F2]

OK, I will repeat the  test on the intake side. This time I will wait for up to a minute to see if there is any splashing of oil from the valve adjusting hole. Pat

[Clyde]

There are two outlet holes from the pressurized oil galleries in the cam towers under each intake rocker which direct the spray toward the exhaust side (although obviously everything gets splashed)

As above.
There is usually very little coming out the inlet side cover apart from some splash. The spray is from the inlet side towards the exhaust valve.

If you are checking, you only need to check the exhaust side.
This I believe, is the most important test of oil flow.

[CB750F2]

Ok thanks Clyde and everyone else that replied. The results of my check confirms what you are saying. Pat