Massively increased fuel economy.

tinysmall · Post by **tinysmall** » Sat Jun 04, 2011 6:39 pm

Ok, so I still haven't got to the bottom of my massively increased fuel economy. The bike feels a LITTLE down on power but not much, other than that it's running smooth, no coughs or splutters or anything. Can't find any leaks anywhere and the plugs are a nice coffee bean brown, carbs are balanced and apart from the small lck of power everythings fine. Apart from my fuel consumption has gone from around 80 miles till the red light of death to now having done 60 miles and the tank still being nearly full. Probably used 4 liters max.

Anyone got any ideas?

benny hedges · Post by **benny hedges** » Sat Jun 04, 2011 6:50 pm

you most likely have an air leak somewhere.
check the breather pipes are on under the airbox, check the condition of the vacuum hoses and possibly could be a diaphragm torn so one pot isnt opening properly.
with the jetting right on mine it's now doing 80 - 110 to red light whereas before i was getting 130 - 170+!
big improvement in power but jeez it sups!

tinysmall · Post by **tinysmall** » Sat Jun 04, 2011 6:55 pm

I'll have to go through it again methinks. Any idea what the internal diameter of the vac hose is? And how do I test it with no visible splits? All the stuff under the airbox is fine but I haven't checked the diaphragms.

benny hedges · Post by **benny hedges** » Sat Jun 04, 2011 7:01 pm

are you sure they are all on properly though????
best to just replace the vac hoses. it's 4mm id

Taz69 · Post by **Taz69** » Sat Jun 04, 2011 7:56 pm

Benny,

Can I ask the question is that for the smaller vacuum hoses, its 4mm internal diameter?

Thanks

benny hedges · Post by **benny hedges** » Sun Jun 05, 2011 8:33 am

yeh mate the hose from the rear intake to the fuel tap and the front one which will either go to your scottoiler or is blanked off for balancing.

Miztaziggy · Post by **Miztaziggy** » Sun Jun 05, 2011 10:18 am

If it's only a tiny bit down on power, but getting such good fuel economy, why fix it? Is it something that is going to do some damage?

If you do 'fix' it, let us know what it was mate, I'll probably do it to mine as a mod...I'll save a small fortune with commuting.

benny hedges · Post by **benny hedges** » Sun Jun 05, 2011 10:56 am

if you want better fuel economy while riding slow you could drop the needles a bit & turn the mixture screw out a turn each.
it will run a bit rough and lose power but the difference may be worth it if you want that sort of thing.
personally i dont mind the economy or lack of it lol... stack it against any other thou and theres not much in it.

tinysmall · Post by **tinysmall** » Sun Jun 05, 2011 11:16 am

It could cause damage if it's running lean yeah. The plugs look ok but it can take time for them to change colour, so it might be running lean now but the plugs haven't changed yet. Lean running can destroy engines in the worst case. And to be honest I would rather have crap fuel economy if it means huge grin factor.

Miztaziggy · Post by **Miztaziggy** » Sun Jun 05, 2011 6:33 pm

What damage does it cause?

I knew running lean on turbos can cause it to run too hot and cause premature detonation, but didn't know it did anything with NA engines. The air isn't under any pressure going in is it?

tinysmall · Post by **tinysmall** » Sun Jun 05, 2011 6:48 pm

Miztaziggy wrote:What damage does it cause?

I knew running lean on turbos can cause it to run too hot and cause premature detonation, but didn't know it did anything with NA engines. The air isn't under any pressure going in is it?

Exactly the same thing with a normal engine. Might take a bit longer but can happen. And that can cause terminal problems.

benny hedges · Post by **benny hedges** » Sun Jun 05, 2011 10:55 pm

most common damage is a bit of pitting to the piston crown and combustion chamber.
severely weak mix and hard riding it can burn the edges of the exhaust valves away and lose compression.
also seen holed pistons (on 2T's) and spark plug electrodes burnt off causing damage to valves.

running slightly weak low down in the rpm wont harm it though but you will lose a bit of power & gain mpg.
best bet for better mpg is sell the storm & buy a cg125

try riding a tuono and you will be glad to get back on the vtr.

VTR1000.ORG