High rpm, low oil pressure?

[gorbys]

I had a chance to go flat out for the first time with my bike and so i did a first to second wot pull and i noticed along with the shiftlight wich is set to 10k rpm the oil lamp flickered ever so slightly. 

I checked the oil before the ride and it was just under the f mark, but I  did do the pull going up a mountain with an 8% incline so i don't know if that has anything to do with it, but I thought I'd ask as I also recall reading somewhere here about swapping out oil pump gears or rotors for later ones? My engine is a 82' 1074cc. 

[Gixer1460]

Other thing to consider is the oil pick up is biased towards the front so under really hard accell, the majority of oil moves rearward and the pick-up gets uncovered! Drag bikes often mod the pick-up due to this. Seeing an oil light anytime under load is never good especially with std. piss poor pressure - the gears would be a good upgrade for any hard use!

[gorbys]

13 hours ago, Gixer1460 said:

Other thing to consider is the oil pick up is biased towards the front so under really hard accell, the majority of oil moves rearward and the pick-up gets uncovered! Drag bikes often mod the pick-up due to this. Seeing an oil light anytime under load is never good especially with std. piss poor pressure - the gears would be a good upgrade for any hard use!

I see. So doing it up a hill wasn't doing it any favours then 

So what do i search for for more info on this upgrade? 

[BillyR]

Ive run a gated sump on most of mine. 

[Gixer1460]

14 hours ago, gorbys said:

I see. So doing it up a hill wasn't doing it any favours then 

So what do i search for for more info on this upgrade? 

search gsx/gs750 oil pump gears - btw they are not easy to find and likely to be spendy!

[davecara]

Speak to @clairetoo

[Arttu]

Yes, stock oil pickup is facing forward so if you accelerate hard enough it will suck air. And like you said uphill makes it worse.

I don't recall seeing flickering light with stockish engine but when I added a turbo it started to happen pretty much always on full throttle. Simplest fix is to turn the pickup around to make it rear facing but then you will get the same problem on braking. Middle position could work fairly well, maybe. Deeper pan with extended pickup and possibly some baffles would be ideal solution if space allows. Luckily the engine isn't very sensitive for short oil pressure drops.

[gorbys]

9 hours ago, Arttu said:

Yes, stock oil pickup is facing forward so if you accelerate hard enough it will suck air. And like you said uphill makes it worse.

I don't recall seeing flickering light with stockish engine but when I added a turbo it started to happen pretty much always on full throttle. Simplest fix is to turn the pickup around to make it rear facing but then you will get the same problem on braking. Middle position could work fairly well, maybe. Deeper pan with extended pickup and possibly some baffles would be ideal solution if space allows. Luckily the engine isn't very sensitive for short oil pressure drops.

Mine is significantly lighter than a stock gs though so i assume it goes harder, at least it feels like it. For now i will abstain from doing long wot pulls uphill 

But i plan to fit an oil cooler so i should look out for a 750 gearset none the less. 

Btw will a gs750 8 valve gear set be the same? 

[bluedog59]

Uprating the oil pump will not stop the light from coming on, it may just take a fraction longer as you'll be coming down from a higher pressure. The route cause is the pick up not actually being in the oil and that is what needs sorting first.

[johnr]

also worth mentioning that the oil pressure switch on these is a pretty agricultural device comprising a spring and a flat disk of metal. its particularly befuddled by modern oil. back in the 80's oil was mineral based gloopy and thick, modern stuff is a fabulously hi tec wonder of science, but its pissy thin watery stuff, so if youre running synthetic oil, before you spend any more money, put some oldskool oil in your oldskool motor.

[Arttu]

Actually the oil light switch is more a flow switch than pressure switch. Pretty much any flow will lift the spring loaded disk off the engine case and turn off the light. I guess that oil weight or quality won't have much effect on it.

[coombehouse]

I used to have this problem but I fixed it by using an oil cooled pickup with a spacer. This brings the actual pickup hole much closer to the bottom face of the sump so it sits deeper in the oil that's there. I also used a paper gasket to seal the spacer & the pickup to the crankcase as there is nothing as standard. Problem gone. 

SPS sell a kit if you don't want to make your own.

[gorbys]

On 8/4/2024 at 2:45 AM, coombehouse said:

I used to have this problem but I fixed it by using an oil cooled pickup with a spacer. This brings the actual pickup hole much closer to the bottom face of the sump so it sits deeper in the oil that's there. I also used a paper gasket to seal the spacer & the pickup to the crankcase as there is nothing as standard. Problem gone. 

SPS sell a kit if you don't want to make your own.

Browsed their site but couldn't find any. How thick is it ?

[coombehouse]

50 minutes ago, gorbys said:

Browsed their site but couldn't find any. How thick is it ?

I had a look too & I could only find a picture of it on their billet sump listing so maybe they don't sell it separately. The spacer I made was 5mm thick I think but it has been a long time since I did it. 

 https://www.suzukiperformancespares.co.uk/product/suzuki-gsx1100-billet-sump-plate/3626/