Sorta quick question

Took my bike out for a ride tonite after work. Put about 70ish miles on her ( Really enjoyed myself ). Anyway, She seemed to sound a little flat tonite, But seemed to be running OK, But not really sure?
She turns 5000 @ 65 mph. in 5th. gear. Is this correct?

Thanks! :thumb:

 

Well since no-one made a comment, I will assume that the rpm VS mph is normal. :tongue:

 

Seems right. How many miles do you put on the bike per week? What i'm getting at is how old is the gas thats in it? The new gas with ethanol in it does not stay near as fresh as the stuff without ethanol did. If its not getting alot of miles put on it you should run fuel stabilizer (sta-bil) all time. I also run a dose of seafoam through the tank periodically to clean the fuel system out.

 

I have put just under 300 miles on the bike in the last week, & have had to fill the tank twice. The first tank I ran a bottle of fuel cleaner, & the next fill up will be doing so again. Oh & I am running 93 octane.

 

93 Octane fuel is a waste of money unless you are experiencing pre-ignition knocking or your engine specifically calls for it which the VF / VFR engine does not. Octane is nothing more than a measure of the fuels resistance to detonation. The higher the Octane the higher the resistance and the slower the fuel burns. Higher octane does not run better, produce more HP, run cleaner, etc even though all the oil companies want you to believe it does.


Rollin

 

Since The bike was sitting for an extended amount of tyme. The fuel that was in the tank when I bought her was old & smelled bad, & she balked & sputtered & popped under a load. I figured running 93 octane & some lucas fuel system cleaner couldn't hurt, even if it didn't help. Plus It was cheaper then pulling the carbs & rebuilding them without trying this first. Right now the carbs seem to be operating properly.

 

is it flat through then entire range or just at cruise? They are set from the factory to run lean between 4-5 and 7-8k rpm (if I remember correctly) to pass emissions. My v45 Sabre pulled like a tractor below 4500 and screamed after 7500 but in the middle it was just down right sluggish. Shimmed the needles and it made a world of difference. My baby ceptor was the same way and shimming the needles on it netted the same result, a much healthier feeling mid range, just not nearly as strong as the Sabre.

If you've ever seen a dyno chart of one of these v4's in stock form the 750 actually drops between 5 and 10 hp in the mid range before picking back up (again, if I remember correctly, pain pills from my recent "flight over a car" have me a little fuzzy).

 

Got her out again today, & rolled another 120+ on the odometer. To me She likes to run @ 4000 rpms & above, From 3RD. gear on up.

Another Question: When the Fuel guage is one bar above the reserve, I have 2 Gallons of fuel left, is this correct or is the fuel guage off?

 

Someone will correct me if I'm wrong but...

Higher octain basically reduces knocking or pre-ignition by making the fuel harder to ignite. This is a handicap but is necessary in really high compression engines due to being prone to pre-ignite due to the heat from the compression alone. As far as horsepower, even though you loose power from the higher octain, you gain more than that is actually lost from the higher compression.

But if you use a higher octain rating than is necessary, you will loose power. You could also begin to build carbon from incomplete fuel burning in the engine which will cause hot spots that will cause pre-ignition problems. Using high octain along with fuel additives may raise the octain rating even higher compounding your problem.

In a nutshell, use the lowest octain rating possible for the best performance. If it knocks move up one grade and try again. Factory calls for 87 pump.