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Wed Apr 30, 2008 8:06 pm

I've had a successful 1st run to the dunes with my new 2276. The dual IDF 44 setup is working pretty well after some experimenting. The current jetting combo is 55 idles, 170 mains, 200 airs in F11 emulsion tubes with 34mm vents. It runs strong on the bowels and hills with the throttle wide open. Transition and off idle response is good. My only issue now is fuel slosh loading it up in the rough and whoops. Currently the floats are set at 12mm, fuel pressure is 3 psi. I'm sure a lower float will help, but I don't want to starve the jet stack by going too low.

Any advice on what increments to try and what is the limit on low float level?

Wed Apr 30, 2008 8:33 pm

There are two settings: upper level and drop. Limiting the float drop helps reduce bounce and helps with slosh (nothing, short of engineering "dry sump float bowls, will eliminate slosh completely). Don't go any lower on your upper level. BTW ... your mains are way too rich. Should be about 140-145 with those venturis.

Wed Apr 30, 2008 9:17 pm

[quote="clearsurf2001
There are two settings: upper level and drop. Limiting the float drop helps reduce bounce and helps with slosh (nothing, short of engineering "dry sump float bowls, will eliminate slosh completely). Don't go any lower on your upper level. BTW ... your mains are way too rich. Should be about 140-145 with those venturis.[/quote]

Thanks for that, I'll reduce the float drop if that will help. I've got it at the recommended setting in the diagram.

As for jets, oh well, I started at 140's, it had lean pops all over the place.
The 170's finally made it happy. My tuning is all seat of the pants, but I can't argue with performance and clean plugs.

Wed Apr 30, 2008 9:33 pm

your jetting is wrong because your floats are wrong. Adjust to 10mm and the mains will work properly with "normal" jet sizes. If you put a wideband on your engine your A/F curve would look like the Himalayas.

For off road use just tighten the drop a bit, like from 20 to 15ish.

John
Aircooled.Net Inc.

Wed Apr 30, 2008 9:45 pm

[email protected] wrote: your jetting is wrong because your floats are wrong. Adjust to 10mm and the mains will work properly with "normal" jet sizes. If you put a wideband on your engine your A/F curve would look like the Himalayas.

For off road use just tighten the drop a bit, like from 20 to 15ish.

John
Aircooled.Net Inc.

When the floats are at 11mm I have spill over into the front aux vents at idle. 10mm would be even worse. I'm compensating for a 7 degree forward tilt of the engine in the chassis.

Thu May 01, 2008 9:45 am

the REALLY correct way to set floats is to set the fuel level. Setting the float level is not technically correct, because it can't account for float mass, fuel density, and fuel pressure (not to mention individual differences in how we set floats (you set them a slightly different way than me for example).

Set the floats, run it for 30 seconds and turn it off. Remove the jetstacks, the FUEL LEVEL should be 4mm below the aux vent port in the main well. If it's not, adjust the floats so that when you reinstall you will be at 4mm below the aux vent port. DONE

John
Aircooled.Net Inc.

Thu May 01, 2008 11:59 am

[email protected] wrote: the REALLY correct way to set floats is to set the fuel level. Setting the float level is not technically correct, because it can't account for float mass, fuel density, and fuel pressure (not to mention individual differences in how we set floats (you set them a slightly different way than me for example).

Set the floats, run it for 30 seconds and turn it off. Remove the jetstacks, the FUEL LEVEL should be 4mm below the aux vent port in the main well. If it's not, adjust the floats so that when you reinstall you will be at 4mm below the aux vent port. DONE

John
Aircooled.Net Inc.

Ok, that sounds like the best idea yet.
4mm below the aux port and tighten up the float drop.