Low Oil pressure after warmed up

[bwanna]

Hey all,

This is for my '82 GS450T, running 10-40w oil. outside temps avg'ing 45-70F.

Symptoms:
-Riding at local speeds around town the oil pressure light doesn't come on.
-Riding at highway speeds for short time light comes on at approx 1100rpm. (longer riding results in light coming on at approx 1400rpm.)
-After riding at highway speeds and then riding at local speeds (cooling down?) the light intermittently comes on between 1100-1300rpm
-After highway riding, then stopping for 5 mins (off) then restarting, no light.

So, it APPEARS the oil pressure gets lower as oil temp gets higher.

Work I've done:
-pulled oil pump and checked all clearance (good)
-replaced oil pump seals
-replaced oil and filter

Any ideas for cause? ... what I can check?

Thanks ahead of time!!
Jersey

[Nessism]

I'd look for a gauge so you can measure oil pressure. The light sensor may be flakey.

[bwanna]

I'd look for a gauge so you can measure oil pressure. The light sensor may be flakey.

DUH... Boy did I miss that one!

I could probably insert an attachment to the same location the pressure switch is located... at least for testing. Any suggestions/experience on placement?

Thanks!

[Guest]

On the right hand side of the bike there is a "Bolt" at the base of the cylinders.

That bolt plugs the oil channel.

You can screw adaptor and your gauge in there.

[bwanna]

On the right hand side of the bike there is a "Bolt" at the base of the cylinders.

That bolt plugs the oil channel.

You can screw adaptor and your gauge in there.

Ok. Great. I'll check that when I get home. Would be nice to have a permanent gauge anyway.

[Guest]

There was a tread recently about them.

The vibration kills them over time. But then they don't cost much.

[bwanna]

There was a tread recently about them.

The vibration kills them over time. But then they don't cost much.

vibration kills the pressure gauge you mean?

[Guest]

I would suggest you pull said bolt and take it to the hardware store, with your newly purchased gauge, so you can buy thea daptor(s) you need.

[Guest]

Yes.

Kills the gauge.

Here is the thread:

http://www.thegsresources.com/_forum/showthread.php?t=221045&highlight=pressure+gauge

[bwanna]

I would suggest you pull said bolt and take it to the hardware store, with your newly purchased gauge, so you can buy thea daptor(s) you need.

Am thinking of using a banjo setup with braided brake line to the gauge.

[chuck hahn]

And dont expect 30 PSI either..an average of around 5 to 7 PSI is what I believe the norm is according to what I have read here. And you can see if the wire is secure at the clip that attatches to the top of the sending unit.

Clean it and add a dab of solder as these crimped on connectors are exposed 24/7 and even though they look good can in fact be loose. A loose connection and the light will come on too.

[bwanna]

And dont expect 30 PSI either..an average of around 5 to 7 PSI is what I believe the norm is according to what I have read here. And you can see if the wire is secure at the clip that attatches to the top of the sending unit.

Clean it and add a dab of solder as these crimped on connectors are exposed 24/7 and even though they look good can in fact be loose. A loose connection and the light will come on too.

I'll check the connectors. Good idea re: solder. I've done that with bulb tips, but hadn't thought of that for this.

I thought the "T" model had a high pressure oil pump? According to the shope manual. Does anyone remember what the max PSI is for the 450T? I seem to remember it being like 80 PSI or something there about.

Thanks!

[chuck hahn]

I didnt look to see what bike you have..but I was quoting what I heard before here on the forum when reading posts. Maybe what i was reading applied to the 750s and 1000s. Does Bikecliff have that bikes manual on his site??

[Nessism]

The 450 has a plain bearing crank and a high oil pressure pump. Look in the manual for the pressure spec. It should be something like 60 psi at 5000 rpm.

[bwanna]

I checked Bikecliff and my Clymer manuals, but no joy.