The stock KX500 cooling system work good on a stock engine under most conditions.
(Use Royal Purple's Purple Ice)..
But there are some of us that push that system to the limit and beyond.
(Use Royal Purple's Purple Ice)..
Apparently the boys over in the UK noticed that when modding the SR's cooling system needed some help.
I found these obscure posts somewhere on the net that got me thinking...
The u.k sr500 90-91 perimeter frame had new separate cast head with 2 inlets at rear this was changed to inlets at front with same casting but machined inlets , In Parallel rads
In European Grand Prix kx500 cooling was a problem all factory and semi factory bikes went to in parallel cooling like the 90 onwards kx250
Maybe because we did not have the massive u.s tracks for cooling but in stock config std kx500 system was no good
for Grand Prix , The U.S Sr500s had the rads pushed out on spacers i believe which made the rad cowls looked flared out
My Sr500 is non perimeter , KHI hand assembled Tig welded frame . Ex Kawasaki U.K bike which was the KHI 500GP Team
Its is thought the 2 inlet kx500/sr head was modified stock not a new casting .