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Fuel economy went to crap with 35 pwk's


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So, over the years, the more mods to the banshee the more the fuel economy has gone down. Many moons ago when I had a +4mm stock ported cylinder engine with 34mm Mikunis, I went 60 miles of logging roads on one tank.  Last year on my 421 cub with 34mm mikunis I could do a 32 mile round trip on logging roads with some gas left in the tank.  This year I just got my whole engine rebuilt and dyno tuned with 35 mm Kehins.  I only made it about 25 miles before I ran out of gas and had to be towed the last 7 miles back to the car.  The bike is running great, I am having a hard time believing that I lost 25-35% fuel economy just by switching to 35mm PWK's.  Doesn't seem possible.

Anybody else have that experience with a cub motor on 35mm pwk's?  I'm wondering if I should have gone with the 33 mm pwk's or would it make that much difference?

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So, over the years, the more mods to the banshee the more the fuel economy has gone down. Many moons ago when I had a +4mm stock ported cylinder engine with 34mm Mikunis, I went 60 miles of logging roads on one tank.  Last year on my 421 cub with 34mm mikunis I could do a 32 mile round trip on logging roads with some gas left in the tank.  This year I just got my whole engine rebuilt and dyno tuned with 35 mm Kehins.  I only made it about 25 miles before I ran out of gas and had to be towed the last 7 miles back to the car.  The bike is running great, I am having a hard time believing that I lost 25-35% fuel economy just by switching to 35mm PWK's.  Doesn't seem possible.
Anybody else have that experience with a cub motor on 35mm pwk's?  I'm wondering if I should have gone with the 33 mm pwk's or would it make that much difference?
How many ponies before and after would probably match de fuel economy....

Envoyé de mon SM-G935W8 en utilisant Tapatalk

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In theory it should't be making a bunch more HP now because it had the same engine set up last year with 34 mm mikunis and went over 32 miles with fuel left in the tank.  Now it has 35 mm PWK's and is dyno tuned, its running great, better than last year, but only made it about 25 miles on the same ride.  One possibility was I was just one the gas a little more than last year, but it didn't seem like my riding was that much different.

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In theory it should't be making a bunch more HP now because it had the same engine set up last year with 34 mm mikunis and went over 32 miles with fuel left in the tank.  Now it has 35 mm PWK's and is dyno tuned, its running great, better than last year, but only made it about 25 miles on the same ride.  One possibility was I was just one the gas a little more than last year, but it didn't seem like my riding was that much different.
My 421 setup with 35mm was drinking fuel for sure.

For my 521 with 39mm, I bought a 20L Clarke tank.

Envoyé de mon SM-G935W8 en utilisant Tapatalk

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duck master

yeah ive pushed my bike back home so many times on my old 421 with 35 pwks.  It literally drank gas, I got less than an hour ride time on my bike.  I was jetted rich af though i think had I jetted it leaner perhaps it might have helped. But yes you are experiencing nothing unusual. 

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