2003 Venture 700 - poor mpg

[oldforgeny]

Hi All,

I'm new to this forum so would you please assist me in trouble shooting my 2003 Yamaha Venture 700 with triple carbs

It appears to run fine but only gets 2 1/2 mpg. The motor needs to reach 6500 to 7000 rpms before it smooths out. (Maybe it's referred to power band).

When compared to my 1998 vmax 700 with triple carbs, it is a lot less. The vmax averages 10 mpg and reaches it power band around 5000k.

What could be possible problems? (The dealer was not able to fix it)
1) dirty carbs?
2) different reed values?
3) exhaust pipe?

Any guidance would be very helpful.

 

[norwegian]

There is a leak there somewhere. Do you smell gas when riding? 2,5 mpg should not be possible, no matter what (trail) sled.

 

[drew24]

X2^ That is a pretty good leak. Check hoses good. Sometimes they get hard and brittle and can crack or leak around the fittings. Also could have some float problems. Also check the pulse line that goes from the fuel pump to the engine and make sure there is no gas in it.

 

[super1c]

Check all fuel lines, if you have a leak this bad you will see it and smell it. Second clean carbs!!!!!!!! Check reeds when carbs are off. When putting back together Make sure fuel screws are at right setting (2 turns out from seate, helps any idle hang. stock 1.5 ). Make sure jets and needles are correct. Make sure choke is adjusted right and cable seated properly. Check oil cable gap (20mm +/- 1mm) And a set of new plugs, BR9ES. If im not mistaken this is the same engine as viper. If this is stuff that has not been done yet start here, you will be surprised. Stock carb spec's http://www.totallyamaha.com/snowmobiles/AAATuning Chart/Specs.htm

 

[shaggyzr2]

The 03 ventures had the redheads in them yet. Could be a clutch problem, make sure both clutches are clean, aligned and check for wear. If the clutches aren't right it can suck gas.