Brumby mixture

scoobymine · Post by **scoobymine** » Wed Aug 05, 2009 4:37 pm

Having a bit of trouble getting the mixture right. plugs are very light on the electodes.which would normally indicate a lean mix. Normally i'd do it by ear, but this time I used a colour tune kit and the screw is a fair few turns out. Are the standard carbies normally hard to tune?
Thanks

steptoe · Post by **steptoe** » Thu Aug 06, 2009 10:05 am

that screw is only for idle mixture of which most don't do too much of so not as important as your cruising or load mixture which is from all those air bleed jets and power jets and main jets in the carby which most wil not bother playing with in a normal hitachi carby, play with a weber is a bit different.

Interesting to see you use one of those colourtune devices from the eighties. I have one never used it and only have one size spark plug end.Might have a fiddle one day.

rubisubi · Post by **rubisubi** » Thu Aug 06, 2009 10:52 am

I tuned mine about 6 months ago, set the timing to 10 degress so i can run it on premium. idle was set at 850 from memory and then the fuel mixture i turned in until it started running rough, then undo it until it idles smoothly. Mines never run better, starts firts pop and i get around 10l/100 kays. Don't forget that when you adjust your timing to disconnect the vacum hose and block it off. Cheers Rubi Subi.

scoobymine · Post by **scoobymine** » Thu Aug 06, 2009 5:13 pm

Thanks Guys, the colour tunes are quite interesting to use. They are supposed to go from yellow (rich) to whitish blue(lean) bunsen blue is supposed to be correct mixture.
I do like to tune the old fashioned way, but this device can pick up engine and fuel problems too!

brenton · Post by **brenton** » Fri Aug 07, 2009 12:29 pm

i thought i heard that you cant really plug read any more due to the leadless petrols and the old tricks only worked on cars running leaded petrol to get a proper reading of them?
cheers brenton

steptoe · Post by **steptoe** » Sat Aug 08, 2009 10:06 am

colourtune is not plug reading - it is a special spark plug that is made of a 'special' clear material body so you view the colour of combustion as it occurs!

brenton · Post by **brenton** » Sun Aug 09, 2009 5:51 pm

cool let us know who it goes, cheers brenton