82 GS650GL slow to build oil pressure HELP!

[SDBuckeye]

I have an 82 GS650GL on which the oil light will not go off until it has been run and revved for about 3 minutes. At that time the oil pressure kicks in and it runs smooth as silk. I have done a bunch of work on it to try to solve the problem but I am at a dead end, as is the mechanic at the local Suzuki dealership.

Here is some background on the situation. I bought the bike in January, brought it home and winterized it. No issues with oil pressure at the time. I didn’t run it again until April. A friend came over to take it on a check ride. The oil light didn’t go off right away, but it did go off eventually. At the time, I thought that was because it was low on oil. He only took it a couple blocks and then I changed the oil and filter.

After the oil change the problem did not go away. I have since that time gone through the following steps:
--replaced the oil pressure sensor
--inspected the oil pump strainer (it was very clean)
--inspected the oil pump, some scratches inside the cover but the gears were good. My mechanic neighbor (and former GS owner) said it looked OK
--inspected the oil pressure regulator, replaced the O-ring
--blew air through the oil pressure sensor channel to clear it out
--I am not burning or losing oil

Once the oil light goes out, pressure stays up. I went for a 15 mile ride without incident.

The local Suzuki mechanic is stumped—his best suggestion has been to try an OEM oil filter.

The above-mentioned neighbor thinks there may be a bolt or plug somewhere else in the engine that is leaking and preventing proper pressure build up. According to the parts fiche at http://www.alpha-sports.com/suzuki_parts.htm there is a jet and o-ring on the crankcase, could this be a cause?

I have run out of ideas. Any thoughts would be appreciated.

Thanks!
Lyle

[Nessism]

Is there a port to hook up a pressure gauge? If so I'd try to confirm whether or not you have a pressure issue or a gauge/light issue. This is pretty darn important since you don't want to ride the bike if there is a true pressure issue. I know that you can purchase a pressure gauge that hooks into the system on the larger bikes...somewhere...so you should look into whether there is a kit for a 650.

[rkubik]

what grade oil?

When I tried synthetic which was 0W-40 in my bike, the oil light started coming on a lot. Went back to ordinary motorcycle 10W-40 last week, and it's fine now.

I believe I've heard others on this forum running 20W-50 if the weather is really hot. That would build pressure too.

[chef1366]

Have you done any work or possibly the PO with silicone sealer? Do you have any silicone squeezing out of any of your gaskets? I really hope you don't have any running around in your oil ports.

[SDBuckeye]

Hi,
It is funny you should mention the oil pressure gauge...I bought a kit from Renobruce. However, in the spot where it is to go into a PO took out the galley bolt and tapped in brass plug. When you run it, you can totally tell when the pressure kicks in. It must be making at least the 30 psi that the sensor requires. I will try and hook it up to the pressure sensor port and get a reading.

I am running 15W-40 Rotella T heavy duty for the oil.

Regarding silicone, there was a very tiny amount in the oil pan, so a PO probably fooled around with it at least a little. One would think that if something is plugged with silicone, the problem wouldn't go away after a few minutes. Maybe the O-Ring on the oil gallery jet is shot?
Thanks,
Lyle

[SDBuckeye]

Oil Pressure Test

Based on a Suzuki manual test of 10 minutes @ 2000 RPM:

0 PSI for 7 minutes, 30PSI or more thereafter.

Thanks,
Lyle

[SDBuckeye]

Problem Solved

Hi,
Thought I'd update this one for the benefit of anyone who searches later. I switched to standard 10W-40 motorcycle oil and the problem was solved.