serious oil pressure question

[Peteortiz11]

Hi all, has anyone experienced this issue with their GS?

I have an oil pressure gauge on my bike (1982 GS850gl) which shows oil pressure while idling and reving when cold. as the bike heats up, I noticed the pressure becomes less and less until I can barely see the needle moving. whats the issue here? thx

[Nessism]

No issue. I'd remove the gauge. It's more likely to cause a problem than help avoid one.

[chuck hahn]

If the gauge isn't very sensitive it just may not be able to read the low pressure these engine operate under. Ive red here that oil pressure is around 5 to 7 pounds.

[Peteortiz11]

Thx Nessism but I don't quit understand your response. are you saying there's nothing wrong with the motor? this is normal for a motorcycle and I should just not look at or pay attention to the gauge?

[Peteortiz11]

Thx Chuck. appreciate it

[roeme]

Thx Nessism but I don't quit understand your response. are you saying there's nothing wrong with the motor? this is normal for a motorcycle and I should just not look at or pay attention to the gauge?

I think he's referring to the fact that these engines have a very low oil pressure, enough to lift oil down from the sump up to the camshaft, but not much more than that. So, not only you'll get different readings depending on where the pressure sensor is mounted, the reading will also fluctuate quite a bit during the twisties.

[Downs]

The roller bearing cranks on these bikes require very little oil pressure. What's the graduation on the gauge you are using?

[Nessism]

The spec is 1.4 psi minimum at 3000 rpm. I doubt your gauge can accurately read this low a pressure.

The oil pump system is virtually foolproof and the biggest chance for failure is your oil pressure gauge springing a leak. As stated earlier, I'd remove it. In all my years here I've never one time heard of even one oil pump failure.

[Steve]

Yep, my first question would be "what is the range of the gauge?", or at least "what pressures are you seeing?"

With a COLD engine, you <might> see 8-10 psi. As it warms up, you are likely to see 3-5 psi.

Not very many gauges read that low, so as Nessism suggests, reduce your chances for failure, don't worry about a gauge.

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[bwringer]

Yep, the roller bearing engines just sort of pump and splash oil around, but there's no need for more pressure than needed to get the oil up to the cylinder head.

A pretty bulletproof system, really.

[Peteortiz11]

Thanks all! I have better understanding now. I'll lose the gauge

[Buffalo Bill]

The GS engine was Suzuki's 1st 4 stroke, after the GT 2 stroke engines. So they built the GS based on their 2 stoke engine experience.

[Nessism]

The GS engine was Suzuki's 1st 4 stroke, after the GT 2 stroke engines. So they built the GS based on their 2 stoke engine experience.

True...and Suzuki copied the KZ900 (which also has a roller crank).

[Steve]

If I remember correctly, Suzuki was the last of the "big Four" to jump into the 4-stroke market. By waiting, they were able to see what worked and what didn't. There were many areas where they might not have been first or best, but were at least a solid second in EVERYTHING, which made them the best all-around bike. They also included features that were not found on other bikes, like self-cancelling turn signals, fuel gauge and gear position indicator. Others might have had one or two of them, but nobody else had all three.

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