Carburation

Garry · Post by **Garry** » Thu Aug 24, 2006 9:27 pm

thats the sort of bill i was going to be looking at - sort of killed
the idea when i told my wife!
mine was due to leaking base gasket letting water in the r/h side
and stripping the bearings of lubrication - luckily managed to free it off with plenty of WD40 and 2 stroke and still running ok - touch wood

moltenmaniac · Post by **moltenmaniac** » Fri Aug 25, 2006 9:19 am

what fuel do u guys run? wen i picked up my 89 kr1 the needle clips were in the second to bottom slot, soon as i tried to run it 91 octane, i had to move the clips up one, i did a top end rebuiild before this though, still not runing quite right, how do i tell if its too lean as i dont want to try moving it up another not and blowing up my engine if it runs too lean!

the-elf · Post by **the-elf** » Fri Aug 25, 2006 11:17 am

I'm not much use on the fuel part as I run mine on Avgas

but as for telling how it is running with the present jetting the best way is to get the bike up to temperature and then do several plug chops at different engine speeds.
IIRC there's a rough carburation and jetting guide on MJ website http://www.teamsparrow.co.uk but this is more of a racers guide to jetting for the weather.

Garry · Post by **Garry** » Fri Aug 25, 2006 6:57 pm

i run both of mine with clips in the top slot - one of them has
nikons and no problems
would have thought mains sizes have more impact on a seizure

the-elf · Post by **the-elf** » Sat Aug 26, 2006 11:38 am

I would guess that for most bikes a 40 pilot jet and a 141 main would be fine for most road/weather conditions.

dangerousdan · Post by **dangerousdan** » Sun Aug 27, 2006 10:26 pm

Would say thats very rich for road riding personally. My road one had a stage 3 SS tune and it ran 135 (standard jet size) main no problem. At a maximum I'd run 137.5 main on the road and with the needle in the middle clip. dropping the needle won't make much difference on a 141 main. Think i ran my needle at 1 notch up from standard (which is middle) with a 135 main. This makes less than a quarter of a percent difference in the mixture but it kept it on the safe side for road riding with that jet.