oil pressure light when riding, off when idlling

[benchrgw]

OK this one has me stumped - recently bought a project '79 GS1000E, finally got running, really runs pretty well considering carbs haven't been sync'd. First crack of throttle half scared me.

At any rate, fresh 10-40 GTX oil, new filter and took for first ride of any length and maybe 5 minutes into it, oil pressure light came on while on throttle. When I stopped to check for anything obvious light went out on idle. Take off again and after short time lights back on, again it goes off when I stop and idle. This seems opposite of what you'd expect usually higher oil pressure at higher rpm's. Bike has after market oil cooler (runs from behind cylinders through cooler and to front of oil filter cover where pressure switch connection is also located.)

Any ideas. My first experience with a GS and I'm really impressed with bikes power, hopefully oil press. deal is minor. Any help would be sincerely appreciated.

[West]

Could be an electrical connector problem showing up when the bike is vibrating. IMO, first thing to do is get a real gauge on the oil line & see what is really going on as far as pressure goes, that will lead you to next step - and you want to know for sure if you are really having pressure issues. Or you could check out the electrical connections first, that is less certain but might solve your problem.

[Guest]

Check switch first thing. I went with a high volume oil pump gear with my oil cooler. You might also want to drop your oil pan and have a looksie.

[Road_Clam]

OK this one has me stumped - recently bought a project '79 GS1000E, finally got running, really runs pretty well considering carbs haven't been sync'd. First crack of throttle half scared me.

At any rate, fresh 10-40 GTX oil, new filter and took for first ride of any length and maybe 5 minutes into it, oil pressure light came on while on throttle. When I stopped to check for anything obvious light went out on idle. Take off again and after short time lights back on, again it goes off when I stop and idle. This seems opposite of what you'd expect usually higher oil pressure at higher rpm's. Bike has after market oil cooler (runs from behind cylinders through cooler and to front of oil filter cover where pressure switch connection is also located.)

Any ideas. My first experience with a GS and I'm really impressed with bikes power, hopefully oil press. deal is minor. Any help would be sincerely appreciated.

Think of your oil pressure switch as simply a "ground".No oil pressure forces the switch to complete a 12V circut by creating a ground for the oil pressure indicator lamp. Good oil pressure forces the switch to loose the ground. (it gets a little more complicated than this, but this is a simple, quick explanation). I am pretty sure you have a bad switch.

[KEITH KRAUSE]

I haven't seen any 1000's with an aftermarket oil cooler routed as yours is.
They generally have the adapter/pressure switch mounted right where the pressure switch is as stock. I don't know if your routing has anything to do with it but I'd try a new pressure switch first and/or check all the wiring for grounding at higher rpm's due to vibration?

[focus frenzy]

with the roller bearing GS engines at least, they do not have a oil pressure switch.
it is a flow switch, it works by having a contact ring that the power wire from the warning light is connected to, when no oil is flowing it covers the oil supply port and grounds the circut making the light come on.

the spring on the contact ring has so little tension to it, any kind of flow will lift it and make the oil light go out.

clutch cable rubbing against the connection and shorting the light on is very common.

how is the oil lever? you need to check it with the bike on level ground on the center stand.

the roller crank GS use a low pressure system, 1psi per 1K rpm is normal, common oil pressure gauges don't read low enough.

[benchrgw]

oil pressure light when riding, off when idlling

Thanks for replies - also off line it was suggested that oil pick up tube might be loose, In any case doesn't appear oil pan can be removed without removing exhaust. Guess I'll start soaking bolts in penetrating oil before attempting exhaust removal.

Any other suggestions for oil pan / exhaust removal - tricks??

Thanks

[Dink]

I think your problem may actually be because of where the switch is located.
The stock position is where your oil cooler is picking up from, at the rear of the cylinder block.
You state it is now located at the outlet from the oil cooler.
That is a very bad location, as you ride the bike oil pressure increases and by passes the cooler as it is not required, this is why it is showing no pressure.
I would suggest going to a dealer(or online/ebay) and purchasing the plate off an 1150 which has provision for two switches, this will allow you to fit the oil pressure switch back to it's stock location & still keep your oil cooler.

Dink

[KEITH KRAUSE]

I think your problem may actually be because of where the switch is located.
The stock position is where your oil cooler is picking up from, at the rear of the cylinder block.
You state it is now located at the outlet from the oil cooler.
That is a very bad location, as you ride the bike oil pressure increases and by passes the cooler as it is not required, this is why it is showing no pressure.
I would suggest going to a dealer(or online/ebay) and purchasing the plate off an 1150 which has provision for two switches, this will allow you to fit the oil pressure switch back to it's stock location & still keep your oil cooler.

Dink

That's what I mentioned too Dink. I've never seen a 1000 with the switch placed where his is.

[Guest]

I think your problem may actually be because of where the switch is located.
The stock position is where your oil cooler is picking up from, at the rear of the cylinder block.
You state it is now located at the outlet from the oil cooler.
That is a very bad location, as you ride the bike oil pressure increases and by passes the cooler as it is not required, this is why it is showing no pressure.
I would suggest going to a dealer(or online/ebay) and purchasing the plate off an 1150 which has provision for two switches, this will allow you to fit the oil pressure switch back to it's stock location & still keep your oil cooler.

Dink

I agree. You have a funky set-up. Get an 1150 cover, or find an adapter similar to mine which keeps the switch at the oil pick up.

[Mojoe]

Any other suggestions for oil pan / exhaust removal - tricks??

Thanks

I have a suggestion for removing the exhaust. Forget about any "soaking" of the bolts and invest in an impact driver. Don't confuse this with an impact gun.
I have recently removed my headers on 4 different old bikes from the early 80's (lord knows when the last time they were removed) and the impact driver was a life saver for all of them. You just set it for "tighten" mode, give it a whack, then reverse it for removal and give another whack with a hammer...maybe 2 to 3 whacks at most and you are good to go. I paid like $30 for mine and it is one of the best investments I have made in a while.

This is not the kind I have....but it gives you an idea what I am talking about in case you are not sure what an impact driver is.

[benchrgw]

Reno - Dink Thanks for your replies - yes my oil cooler set up didn't make sent to me either and I could find no info. on my current set up.

Reno the adapter plate you show has oil cooler lines coming back to it (rear facing in your picture) and pressure switch (facing down, right side of bike)
Correct?? Any idea where you got this plate?

If not any longer available, what's the 1150 set up look like.

Thanks - Guys - sincerely appreciated.
Bench

[benchrgw]

Thought I better make sure I had clearly described what is on bike, wish I had good pictures - need to work on that.

One hose comes from original oil pick up area behind cylinders and goes to oil cooler, other hose from cooler goes to the oil filter cover which has been fabricated to have a hose barb on it. The center of the oil filter cover has been machined to accept the oil switch which appears to be just a spring loaded valve / switch. Wire from this switch run back to the connection behind the cylinders (under the starter cover)

Does this sound like a familiar cooler to anyone? Maybe I should junk it and start over moving switch back to original location and checking from there.

[Guest]

Reno - Dink Thanks for your replies - yes my oil cooler set up didn't make sent to me either and I could find no info. on my current set up.

Reno the adapter plate you show has oil cooler lines coming back to it (rear facing in your picture) and pressure switch (facing down, right side of bike)
Correct?? Any idea where you got this plate?

If not any longer available, what's the 1150 set up look like.

Thanks - Guys - sincerely appreciated.
Bench

I think I got lucky with finding my adapter. I bought it off an 850 that was being parted out on ebay. I bought the cooler and asked if the buyer would throw in any adapters that came with it, which he did. I then sold the cooler (I had a brand new one) for the same price:-D .
They are hard to find. There is a guy from Australia on this site (Terry?) that sells an adapter that is similar. Do a search for adapters.
I could be wrong, but I don't think the 1150 cover will work on the 8 valve motors... the cover pattern is different.

[Guest]

Here ya go....... http://www.thegsresources.com/_forum...t=terry+cooler