Test results gas mileage with 42# injectors

[Mark S]

Last year with a Rotax stage 3, pre-reflash ecu and the stock injectors with normal average 40-50 mph riding and not excessive wot operation I averaged from around 5.7 to 6.0 mpg and saw a best on smooth water of 6.2 mpg. Recently added the reflashed ecu, new +2psi impeller and 42# injectors , along with a steeper prop (Solas 14/18.5 or 14/19.5 before and Skat 14/19 3-blade currently). Went out tonite and rode 25 miles up the Illinois river and back. Water was anywhere from light wind ripple to 1 1/2 foot of chop. Kept my average speed between 40 and 50 mph (5000-5900 rpm) did a couple of wot runs and a few wot acceleration runs out of the hole. Went 50.2 miles (gps said 50.2 ski odemeter said 54.5) and used 8.2 gallons of fuel. That's 6.1 mpg. I honestly think I am getting slightly better gas mileage now than I was with the old setup. I wasn't expecting this at all. Obviously, if you spend a lot of time at wot your fuel economy will suffer. For those of you concerned with going on long rides with the new sc'r and 42# injectors, if you can control your finger you should have approx. the same range as before. If you figure the tank needs a gallon of fuel for the fuel pickup minimum that would give you a range of approx. 90 miles. 290 hp and still have a range of 90 miles.

[GPR/STX-15F/RXT]

Mark, this info is FANTASTIC!!!! more HP and more speed with the same fuel consuption thank you very much, now, were is my damn credit card,? OH i just find it

Ray

[HOSS]

This is exactly what I`ve been saying. Now on the hammer you will burn much more fuel than stock injectors.

[Kinchyle]

Did the older flashed ECU's dump more fuel ?
Do you think possibly the new ECU vs old ECU could have given you the better edge with the new setup?
Still seems pretty good though.

[bankyf]

I believe that it is a well known fact that the reflash is leaner than pre-Reflash.

[Vern]

Mark, do you have an A/F gauge? I would be curious what your A/F ratio was with your setup ...

[Mark S]

I don't have an air fuel gauge. I have put around 4 hours on this setup so far with no problems. Ran it quite hard yesterday. No problems with the Riva exhaust melting or anything. I'm sure it's not running lean. Mark U. said there would be no issues with the 42's and this setup. Also, it does idle fine for 5-10 minutes at a time in the water without appearing to load up. Running even better now, had 7 gallons of 6 month old gas to which I added 4 gallons of 100 octane turbo blue and 5 gallons of fresh 93 on my gas mileage test. The tank after that gave me noticeably better acceleration but no increase in top speed.