Periodic loss of oil pressure

[f-okie]

Ok guys, lets see if someone can figure this one out.
After some riding, and the bike being nice and hot, I'll stop and have approx. 15-20 lbs. pressure at idle. I'll run into the store and return about 5-10 mins. later. When I start the bike, I'll have NO oil pressure. It will stay this way for a couple of blocks then start to rebuild pressure. I've checked the oil temp when this happens, and it's never been over 190-195 degrees.
Any ideas?????

 

[Fibersnake]

Make sure that you clean out the oil pump strainer. Also check to see if there is any debri or crap that may be slightly restricting the oil pressure gage line where it is connected on the bike. Other than that, the next idea would be to check the check ball under the strainer and maybe seat in case it is hanging up.

It is fairly easy to do, just get a small magnet or something that wil fit in the hole that can grab the ball. Pull it out and take a small wooden dowel with a clean lint free rag, saturate the rag with brake cleaner and gently wipe the seat area for the ball in a smoot circular fashion. Blow out with clean air and re-install ball, clean strainer and then put back together. Make sure that the strainer is put in right as well as the spring.

Might as well change oil and filter at the same time to just be on th safe side.

Other than that, can not think of anything else. Maybe someone else has ran into similar problem and has a better idea.

Good luck and let us know how you make out.

Safe riding.

Oh is you Oil Pressue light working normal, i. e. on when stop with power and goes off within seconds after starting?

 

[Raywood]

If you pressure gauge is mounted on top of the oil tappet screen then I would say it's dirty as FS stated. That is a good reason not to mount it there as I've posted in the past.

Clean the screen then see if it's working properly.

 

[Vegas]

I agree with these guys...I really doubt it has no pressure or you would know it. That being said make damn sure you have a gauge problem.

 

[f-okie]

Thanks guys-I'll try it. The light appears to be working(on at key on, off after starting) and its never came on while the engine is running.
I'll check the gauge as well.
Ray-where would you suggest tapping into?

 

[Raywood]

Thanks guys-I'll try it. The light appears to be working(on at key on, off after starting) and its never came on while the engine is running.
I'll check the gauge as well.
Ray-where would you suggest tapping into?

As stated before in these threads I use the fitting at the rear of the back Lifter box. This way you can clean the tappet screen regularly.

 

[Vegas]

I like how you use the stock sender Ray. There is now way in hell to look down at your oil pressure riding. :2thumbs:

 

[f-okie]

Thanks Raywood:flag:

 

[Gas Man]

And just to be clear... during this "no oil press" time the oil light in the gauge cluster never came on??? Correct?

 

[chacha]

Some of these gauges will show zero when they overheat. The diaphram can go soft untill it cools. I've had this happen before, works fine after it cools a bit.

 

[f-okie]

That's correct Chris-
I've often wondered if it might be the gauge. I'll be replacing it soon-
I've cleaned and checked as FS suggested. Still thinking of adding a temp gauge, just trying to figure out where to get the best oil temp from.

 

[Gas Man]

Which gauge do you have?

I put the dipstick temp gauge in the wife's sporty and it works great. Just wish BDM had one that fit all the bikes!!

 

[dogvet]

pinch off the vacuum line going from the intake manifold to the front head or remove the oil cap with the engine running. You'll see an immediate jump in oil pressure. At idle, you have maximum intake vacuum applied to the engine (and oil tank via the vent hose). The oil pump is a gravity feed set up and it's trying to suck oil up about 18 inches of oil line or so from a tank with vacuum applied to it. Not much difference in pressure between the oil pump feed and intake vacuum at idle.

A loose feed line can cause the same symptoms.:zz2cents:

 

[Korben Dallas]

I don't want to hijack this thread, but do all Big Dogs come with the HVHP oil pump?

 

[dogvet]

All the 117's do.

 

[Korben Dallas]

Got cha, thanks
:up:

 

[f-okie]

Well, I pinched it off at idle, and had no change

 

[dogvet]

Well, I pinched it off at idle, and had no change

Check for a loose feed line or fitting. Might see what happens when you loosen the oil cap as well.

 

[f-okie]

I checked for loose fitting--nothing.
Stupid question-if there was a loose fitting, wouldn't I lose/leak oil?

 

[dogvet]

I checked for loose fitting--nothing.
Stupid question-if there was a loose fitting, wouldn't I lose/leak oil?

You would in a gravity feed system, but on these bikes the pump is sucking the oil out of the tank.