Originally Posted by RicardoJM
The Blue Mule is running a DD38 on a 2F and many others have success running the combination - I think that Martin has this set up in his rig. Regarding jetting, we put in a slightly larger jet (118 IIRC) in the Blue Mule and noticed a performance improvement. I don't think that Randy tracks MPG so we don't know what the economy impact is. That said, I don't think the Mule will be going back to the smaller jet size.
I dont track mpg closely, but when I have done it it worked out to 10-11 mpg. I think the Mule is really heavy with all of the tube work and the 37" tires with steel beadlocks probably add a lot of weight too. And, I know my speedometer is 5 mph slower than actual vehicle speed so that probably factors in.
I had a significant increase in power when I went from the stock jet sizes to the larger ones. It still runs smooth, no black smoke, no plug fouling and the power is much better. It ran good on the snow run too so getting a little higher up didn't seem to make it too rich either.