oil pressure light flicker

[tony7914]

hi there,
it's been a long time since i've posted! i have a question about a flicker i get in my oil pressure light when i decelerate rapidly. i'm not sure why it does this. my 79 special has new oil and filter and "O" ring. the only time it does this is when i get off the gas suddenly or if i make a fast stop. is this normal or should i start worrying?
any help would be great!

[GNEPIG]

.. hi i had this problem once, i found it to be that the circlip had came off the end of the shaft that holds a idler gear on the end of [if i can remember correctly] the shaft that holds the shift forks up ..the gear cant fall off but sometimes it moves over just enough to lose contact with the oil pump gear
.. i also noticed this happening [the oil light coming on] sometimes when i was hauling ass..
.. i found the circlip in the oil pan, it was not a big deal just put another clip back on

[Dennyz]

FYI: On a special, the oil light is also a tail light "Out" indicator. I picked up a '79 Special with 19K on it. The PO was sure the engine was toast because he road it home with the oil light on. Replaced the tail light bulb, problem solved.

[MAXIMAN]

Tony

Does it do it only in the first few minutes of driving?

Mine will do this during the first few minutes. But after the bike is up to operating temp it stops. I assume when the old is cold it will stack up at one end of the pan upon hard acceleration or stopping. Obviously the phenomenon is more accented when using heavy old.

I had same problem this fall while I still had my summer oil in (20w-50). I switched to 5w-30 and it went away. But I went back to 20w-50 this spring. A couple days ago in the morning the temp was in the 50's. I saw the light flicker again. So I drove at a moderate pace until the engine got up to normal temp. never saw it after that.

One more thing. When the bike is on the center stand and level...where is the oil level in the sight glass? I keep mine slightly high....right up to the top mark. That would seem to help the oil pump from starving.

[tony7914]

hi there,
thanks for all the replys!
the oil level is just above the top line on the center stand. using 30 weight oil and it normaly happens after the bike has been running for awhile. usualy if i let off the gas suddenly or do a hard stop. the wire is tight on the sending unit (going to pull it and clean it soon). the light doesn't stay on it just flickers a bit. the tail light looks alright but i'm going to swap it out to isolate that possible cause. i've thought about dropping the pan to look at the circlip you spoke of, can that pan be removed without pulling the engine from the bike?
thanks again!

[GNEPIG]

.. yes you can take the oil pan off with the motor in the frame
but first check the options the other two gentlemen have sugested. we dont want you go way out of your way only to find that it was something so simple
but if all else fails.. it might be easyer to remove the clutch cover, if you lean the bike against the wall on the left side you would not have to dump the oil
.. you will have to remove the clutch assembly to get to the gear
the gear is on the bottom right side behind the clutch basket
you might be able to see the oil pump gear that it locks with

good luck gene

[TopCatGr58]

Hey Tony,

Before you go pulling the pan, (yes is can be removed without pullng the engine), remove the sending unit, and give it a good cleaning with some spray carb cleaner, and perhaps a small piece of wire, something that you can stick inside of it to manipulate the plunger device to work loose the old oily sludge that may have built up inside of it! Then put it back on! With summer approaching/Here tomorrow, I would highly recommend a higher viscosity range of oil to run.

These air cooled engine get quite warm, and the oil does thin out a bit, and with it thinner, upon decel and reduced engine rpms', the pressure will drop, which will cause the sensor mechanism to possibly drop...not being held up by enough pressure, and makes contact/ground causing the light to flicker! As you described, it happens more after the bike has been running a while=hotter thinner oil!

[tony7914]

hi there,
thanks for the advice!!
any recomendations on the oil? i was thinking 20/50. i'll pull the pressure sensor tomorrow after i give her a bath!
thanks again!