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Main Area => General GS500 Discussion => Topic started by: IvánT on September 06, 2026, 06:26:29 PM

Title: GS500F oil cooler conversion pressure drop help
Post by: IvánT on September 06, 2026, 06:26:29 PM
Hi everyone,

I am doing an oil cooler conversion on my GS500E using complete GS500F OEM parts (oil pan, lines, radiator). My bike is a 2016 model.

I have plugged the upper hole behind the oil filter with an NPT plug and drilled a small 3.1mm bypass hole in the lower crankcase port.

With a permanent oil gauge, I am getting 3.5 bar when cold, but it drops to 0.4 bar at hot idle (100°C) and only goes up to 1.5 bar when accelerating.

I know the original GS500F uses an internal restrictor bolt (the one removed with an 8mm allen key). Does anyone know the exact inner millimeter diameter of the hole inside that factory restrictor?

I want to know if I should drill my NPT plug to match it, and if I need to widen my lower 3.1mm hole to prevent backpressure.

Thanks for the help!
Title: Re: GS500F oil cooler conversion pressure drop help
Post by: herennow on September 08, 2026, 02:42:10 PM
That's an interesting project. Where did you get all the information about the steps to do? Can you post some pictures? Be interesting to look at and to follow along.