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MPG?

Posted: Mon Nov 03, 2014 11:43 am
by Biker_Bob
What sort of MPG are you getting from your 3HE?
I'm not getting the sort of range I was expecting from it, it seems a lot more thirsty than my 4JH.
Mind, I have been doing quite a bit of high speed test riding recently (100+ for extended periods), I guess the economy drops off somewhat in that case?

Re: MPG?

Posted: Mon Nov 03, 2014 12:28 pm
by DonTZ125
Biker_Bob wrote:I have been doing quite a bit of high speed test riding recently (100+ for extended periods), I guess the economy drops off somewhat in that case?
Yes ... The faster the bike goes, the faster the gas goes. Bear in mind too that drag goes up with the square of your speed - double the speed, you face 4x the drag and need 4x the fuel to overcome it (assuming other factors don't also chime in).

Re: MPG?

Posted: Mon Nov 03, 2014 2:05 pm
by Biker_Bob
Thanks, yep I get all of that - but I'm after a real world figure for what it should be.
My 4JH seems significantly better on fuel, just wondering if this was normal?

Re: MPG?

Posted: Tue Nov 04, 2014 4:00 pm
by pefrey
A lot will depend on your gearing. Are you running 15/45 or something else?

Re: MPG?

Posted: Tue Nov 04, 2014 4:01 pm
by pefrey
It will also depend on jetting. If your carbs are set up rich, or you have a Stage 3 kit, state of tune etc.

Re: MPG?

Posted: Thu Nov 13, 2014 8:00 pm
by Harrysf707
43 MPG average here, 75-80 MPH backroads/highways very little city. But, my jets are running retardedly rich...

Re: MPG?

Posted: Tue Nov 18, 2014 10:06 am
by fink
Stock 45-55. Stage 1 w/ header 38-45.

Re: MPG?

Posted: Tue Nov 18, 2014 12:19 pm
by pefrey
fink wrote:Stock 45-55. Stage 1 w/ header 38-45.
This seems about right to me. I was getting about 50-55 on my stock bike, then added a Stage 1 and 47 tooth rear sprocket and dropped to 35-45 range.

Re: MPG?

Posted: Thu Nov 20, 2014 3:35 pm
by pefrey
When I say dropped from 50-55 down to 35-45, there's also a transfer from street to track. So, I was getting 50-55 on the street (very tame riding, shift around 5 or 6 and cruise around 3-4K) to 35-45 with Stage 1 and sprocket change on the track (keeping revs above 7K).