Hey Guys,
My RB30 doesn't run on LPG well since the replacement of the cylinder head.
It runs really well on petrol.(I haven't checked the AFR or tune the carby yet though)
I cleaned and renewed all the earth wires and added more earth connections and also cleaned and renewed
connections in LPG wiring. Ignition leads are fine. AFR gauge shows good AFR(14-15).
Basically it sounds like it's starving of LPG, but not sure 'cos LPG economy is pretty bad.
I put 30 litres and got about 100k out of it, so it's horrible economy for LPG.
It idles ok on LPG with a very slight misfire, but not all that bad.
Problem starts when under load. It gets worse as the engine gets hotter.
Cylinder head I put on it came with spark plugs NGK BCPR6ES-11, so I didn't change it.
The factory recommended one is NGK BKR6E.
Is this the problem?!!
Checking the plugs on NGK website there isn't a whole lot of difference between them other than the 2.5mm height difference on top side.
https://www.ngk.com/product.aspx?zpid=9292
https://www.ngk.com/product.aspx?zpid=9292
BCPR6ES-11 has JIS height while the BKR6E has ISO height, so I reckon it's basically the same plug with different height on the top.