Good Afternoon All,

I own an MK Indy with 919 Engine, I've just completed the construction of my own airbox. It runs fine, but smells quite rich. It was previously running a sausage filter and even then smelt quite rich. The main jet is currently 132, what would the standard recommendation be for the engine with a non standard airbox on?

Thanks for your help!

I suggest you call Andy Bates at AB performance and ask him.

When I ran carbs it had a couple of flat spots with free flowing exhaust and filter, this was resolved with a dynojet kit.

Just tuned a fireblade in a Westfield.

120 mains (stock size I think)

Solder up the air correctors

Dyno jet springs

Fuelling 12.5afr full load on the dyno, 13-14afr light throttle.

..... Needles 3 from the bottom.

The really early ones didn't have needle adjustment, it doesn't have much effect WOT anyway just useful to lean off part throttle.

Hi
done literally hundreds of these - best set up that we use every time

Mains -132
Pilots 21/4 - 21/2 turns out from home
Block air correctors
Needles - FLTV50 with e-clip on second groove from top (stock seat washer installed no shim)
Heavy duty lift springs
Job done - missile

Note this will only work well if using a stock self regulating fuel pump as fitted to early blades (893)
Facet fuel pumps and regulators simply don't work properly and will result in small main jet sizes to compensate for high pressure in float bowls forcing fuel through main jets - whilst it will run, about 1/3 of the fuel is wasted and expelled unburnt through the pipe resulting in popping banging and silencer packaging that lasts no time at all
Worst case using the facet and reg set up was when someone left the ignition on for several hours - fuel pressure forced the float bowls down and made its way up the emulsion tubes and filled the bores slowly - result was a hydraulic lock of the pistons followed by a blown engine as it had also made its way down into the sump and thinned the oil. When I drained it there was nearly 5 litres of fuel/oil mix in the sump! - oh and a lot of engine fragments

If you need any more info give us a call on 01449 736633
Best regards
Andy

Is it the same tuning for engine with airbox?

Hi -
if using our airbox where the float bowl vent pipes are pressurised at the same time as the carb intakes then yes as the increased pressure in the box is balanced and so automatically compensated for
Best regards
Andy

Thanks for all your help guys, that's brilliant!

quote:

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Originally posted by Andy B
Hi
done literally hundreds of these - best set up that we use every time

Mains -132
Pilots 21/4 - 21/2 turns out from home
Block air correctors
Needles - FLTV50 with e-clip on second groove from top (stock seat washer installed no shim)
Heavy duty lift springs
Job done - missile

Note this will only work well if using a stock self regulating fuel pump as fitted to early blades (893)
Facet fuel pumps and regulators simply don't work properly and will result in small main jet sizes to compensate for high pressure in float bowls forcing fuel through main jets - whilst it will run, about 1/3 of the fuel is wasted and expelled unburnt through the pipe resulting in popping banging and silencer packaging that lasts no time at all
Worst case using the facet and reg set up was when someone left the ignition on for several hours - fuel pressure forced the float bowls down and made its way up the emulsion tubes and filled the bores slowly - result was a hydraulic lock of the pistons followed by a blown engine as it had also made its way down into the sump and thinned the oil. When I drained it there was nearly 5 litres of fuel/oil mix in the sump! - oh and a lot of engine fragments

If you need any more info give us a call on 01449 736633
Best regards
Andy

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