GS750 GS650? Oil Pressure

[wharrah]

While we are on the subject, does anyone know what the pressure level is on a roller bearing 750 with the high output gears?

not gonna ASSUME that they are the same as the 650s, eh Bruce? \\/

[renobruce]

not gonna ASSUME that they are the same as the 650s, eh Bruce? \\/

The "low pressure, roller bearing crank" 750 's have higher volume oil pumps. So even though they run at the lower pressure, I assume the pressure is slightly higher than the standard 2-8 psi. I was just wondering by how much.

[tconroy]

What i would like to know is which is best? Or does it matter?

[wharrah]

What i would like to know is which is best? Or does it matter?

Bruce needs to know the specific pressure, because he wants to fit the right oil pressure gauge to the right engines...

Now is the time for someone with a 750 manual to chime in.....

[Hap Call]

The "low pressure, roller bearing crank" 750 's have higher volume oil pumps. So even though they run at the lower pressure, I assume the pressure is slightly higher than the standard 2-8 psi. I was just wondering by how much.

A 0-15 PSI gauge should work fine. If you use a 0-30 PSI it is hard to tell the pressure at the low end during idle and with the oil hot.

Hap

[renobruce]

A 0-15 PSI gauge should work fine. If you use a 0-30 PSI it is hard to tell the pressure at the low end during idle and with the oil hot.

Hap

Thanks, Hap!

[wharrah]

The gauge is installed on my GS650L.. and its SWEET.

Kids...

The deed is done.

I have a fully-functional (and great looking) 100psi oil pressure gauge on my GS650L. I found out my bike has GREAT oil pressure! And, this thing should make most of you plain-bearing folks with the low-side journals happy.

RenoBruce has the details, as I did a writeup for him tonight. I have pictures you can see for yourself...

Initially I had nothing to gain from this activity. As a result of my assistance (and willingness to be a guinea pig), I ended up with the specimen you see here, which he donated to me for my ongoing efforts to bring you a good product. But, it is very much worth the price if you'd like to have a visual indication of oil pressure to go along with your idiot light on your dash, which, of course, is unaffected by the presence of the gauge. Its a GREAT SETUP. Otherwise, I have NO FINANCIAL OR OTHER INTEREST in this project whatsoever. RenoBruce supplied the parts and I supplied the 'mule' for R&D.

You can see the gauge both WITH and WITHOUT my engine case guard, which went on with no added difficulty whatsoever.

I will post some writeups this summer after I get a few miles on the old Girl and let you know how its going. But I imagine that I won't have any trouble.

Here is the link to take a peek. Any cost or availability questions to to RenoBruce. I was just the 'Vanna White' of this little activity, for you GS650L owners out there.

Happy trails! \\/

http://s153.photobucket.com/albums/s216/pilotguy1050/

[Steve]

I find this discussion interesting. All this talk about how HIGH the oil pressure can/should be.
Please remember that it is not pressure alone that lubricates the engine.

Imagine, if you will, that the gauge is on a "T" fitting right after the pump.
Also imagine that the leg of the T that sends oil to the engine is completely blocked.
Pressure would be fantastically high, wouldn't it? :shock:

I think you get the picture. Unfortunately, I have never seen a practical way to measure oil flow, so we will still have to rely on pressure readings and hope there is not an unnecessary restriction in the system somewhere. :-({|=



.

[Cassius086]

How can that be? I have sold a few oil pressure gauges for some 16 valve 1100's and the 0-15 psi gauges work fine. If the pumps are the same, why would a 650 or 750 run at 43-78 psi?

Shop manual for my 1100EZ (82) states the bike has a high volume, low pressure pump.....do not have near me for exact psi numbers, though.

[renobruce]

Imagine, if you will, that the gauge is on a "T" fitting right after the pump.
Also imagine that the leg of the T that sends oil to the engine is completely blocked.
Pressure would be fantastically high, wouldn't it? :shock:

Yes it would. The oil flow configuration IS alot like you imagine above..at least on the roller bearing engines. The oil flows from the pump up to the pressure switch and then dumps back down and also "T's" over to the oil gallery bolt. If you have a blockage you will read higher than normal pressure. If your oil strainer (which is BEFORE the pump) is blocked or dirty, you will read lower than normal pressure (as my bike was).

I think you get the picture. Unfortunately, I have never seen a practical way to measure oil flow, so we will still have to rely on pressure readings and hope there is not an unnecessary restriction in the system somewhere. :-({|=

Well, one way of checking it is to leave the oil gallery bolt off!:shock: With all the testing and experimenting I've been doing, I have left if off a few times. It will puke oil out about 2 feet!