Topic: If it ain't one thing it's another

[Borkunit]

Going on a mellow evening ride tonight, the oil light came on and stayed on  .  The engine was making no abnormal noises and didnt seem excessively hot.  I wasn't far from home so I coasted back and tried not to rev the engine.  Still no abnormal noises, knocks, ticks, etc. Oil level is fine as checked by the dipstick in the oil tank.

Any tips as to proper diagnosis of the oiling system?  how can I find out if oil is being pumped without a pressure gauge?  Are the pressure sensors a typical wear item?

Thanks a lot!

-Zak

[Steve F]

You can check for oil being pumped through the engine by removing one of the valve tappet covers on the INTAKE side (don't take an exhaust side plug out unless you like oil all over the front of your engine).  If you see oil squirting about, you should be fine.  Get a gauge anyway and attach it where the sending unit goes if you can and take a reading.  At idle and the engine cold you should have about 20 to 30 psi, and as much as 60 to 80 psi when reving the engine.

[Borkunit]

Thanks Steve F. 

I started it up today and the oil light went off after the engine fired.  I removed the valve adjusting port and could see oil moving on the rocker arm shaft.  I didnt see any oil splashing about in the area where the rocker arm actuates the valve. 

When I removed the valve adjustment port cover, it popped off with a *foop* as the valve cover area was pressurized.   As I watched, the bike progressively ran worse and worse, almost as if there was too much choke (choke was off) or the plugs were loading up.  I sould rev it up a bit and it would be better for a few seconds, and then it would start to chop again.  I hit the throttle again and the motor died.  I may have not turned the idle up far enough.  The bike was at ambient temperature after sitting all night. Unfortunately I do not know this motor well enough to know what to expect from it in terms of its quirks, noises, and behaviors.

I checked the oil level again which WAS low (off the dipstick, OOPS!) but I could see oil in the tank.  When I removed the cap to the oil tank, it too was pressurized and hissed out slowly as I loosened the cap.  I decided to come inside and mull the situation over and update this post.

Anyone have any additional thoughts? Is the pressurization in the valve cover and oil tank normal and acceptable?

Unfortunately I am leaving on vacation tomorrow and won't be able to look into this until I return, but I welcome any suggestions.

Thanks,
Zak

[riktaboy]

by golly, welcome to the world of owning a old bike...
Tear the whole thing down and rebuild everything, that way you'l know exactly where your at when something goes wrong right>

[Borkunit]

Not a bad idea... Gotta have a have a baseline to work from, right?

[TwoTired]

No, you don't have to take it all apart right away.  I can only hope riktaboy was being fascetious.

However, the crank case should not pressurize.  There is a breather hose near the top of the engine.

I don't know which bike you have, but you should track down where it is plugged up and clear that so it can equalize pressure with the outside atmosphere.

Cheers,

[Boomologist]

Pressure in the crank case will force oil into places it normally wouldn't go. If you have a seal somewhere that is close to leaking the additional pressure will make it leak. This would explain the low oil. The leak will usually show on the outside of the engine, but it may not. It could be leaking internally such as valve guide seals or piston rings. As someone stated earlier, the crank case should be vented to prevent pressure. You need to find what is plugging the vent, then determine if there is excessive blow by.

[petercb750]

Zak - when I bought my bike (K2 750) the crankcase breather had been connected back to the oil tank - sealed system! Couldn't work out what the hissing noise was when I turned it off, and then realised that it was coming from the oil tank cap, like yours did. Re-routed the breather and problem over.
Years ago I had an 1100F and put a nice 4into1 on it - not realising that the breather tube came into contact with it and melted the end, again sealing the system - oil found it's way through the top breather and straight into the air box - what a mess!
So there's a couple of things for you to check. Hope it helps.
Peter.

[Borkunit]

Thank you for the responses gentlemen.  I am stuck in Alaska at the moment, but the diagnosis process will begin in earnest when I get back to sunny and warm Oregon on the 11th.

I'm going to do an oil change and take a look at the breather situation and go from there.  Hope my new baby is OK!

Thanks,
Zak

[Borkunit]

Back home now.  Took a look at it and, yes, the crank case breather was connected to the oil tank breather.  Both of these are supposed to vent to the atmosphere, right? 

Well, I finally have found a home for the "extra" tube that was in the Big Box o' Mystery Parts that came with the bike.  Seems to fit the oil tank breather perfectly

Thanks,
Zak