Hi , my trusty TB42 carbie is getting old. The 1989 GQ safari has done 400k , not sure about the engine.
Over the last year or so it slowly lost its interest in climbing the steep Mountains of Warrumbungle N.P. - the engine still runs beautiful steady. A joy to listen to. No real oil loss - barely worth topping up between oil changes. But the torque going uphill is gone.
I run DUAL FUEL , 90% on Gas.

Today did a compression test and spark plug check , hope that tells it all to the specialists between you:
Cylinders from front to rear - 1 __ 6
Cyl 1: 120++ PSI , spark plug almost clean , just very slight black sooth over a very thin layer creamy brown - blue spark.
Cyl 2: 100++ PSI , spark plug almost clean , just very slight black sooth over a very thin layer creamy brown - blue spark.
Cyl 3: 120 - - PSI , spark plug very dirty , a brownish scale all over , red spark.
Cyl 4: 120 - - PSI , spark plug reasonable clean , just very slight black sooth over a very thin layer creamy brown - blue spark.
Cyl 5: 80 PSI , spark plug a little blackish - blue spark.
Cyl 1: 100 PSI , spark plug a little blackish - blue spark.

As said negligible oil use , barely worth topping up before oil change.
A small amount of coolant use. I suspect it leaves mostly via the old expansion bowl. Maybe 4 litres over 10000 km or one year for me.
I drive only medium long distance as we live 45 km from town and go there only once a week. Very very few short trips on the large property.

WHAT DO YOU SUGGEST:
Just the head a reconditioning ?
Get rid of the carbie setup and get a EFI setup ?
As said I run 90% on LP gas .

I also run on an Auto gearbox , convenient but the 3 gears are not my favorite in the mountains here.

Thanks !
Jacob