crappy gas mileage on my 1986 vf500f

About two months ago I bought a 1986 interceptor 500. I love absolutely everything about the bike except for one thing. the best gas mileage I have gotten out of it was 25 MPG. I do mostly city riding around my college town, to and from classes. I have a friend that does pretty much the same riding that I do and his katana gets about 50MPG. Everything else on my bike is great, idles nice and strongly at 800-1300 RPM depending how warmed up it is. Starts easily in the morning no matter how cold it is. What are some things i can check or do to improve my mileage. It is not fun having to get gas every 70miles. Although, its still no contest on city MPG compared to my car. so not complaining if its not an easy fix. LOL.

--Elliott

 

Your car must be a BEAST!

I am sorry. I had to. Welcome to the forum, hopefully someone with some knowledge will be by shortly to lend some advice.

 

Make sure your choke is fully returning and the cable is not adjusted too tight. A friend of mine had that issue on his katana and it caused the choke to hang open slightly, it killed his gas mileage. I ride my 5th gen to class only 2 miles away every day and I get about 38 mpg doing that. I try to get out at least once a week and let her stretch her legs, get fully warmed up, burn off any excess fuel that may have accumulated in the oil from short trips, and all that good stuff. Doing that I get 45-48 mpg. Just to make sure it isn't running conditions, take the bike out on a nice ride that doesn't involve city riding so she can cruise for at least 75 miles. Then gas up and report back your mpg and we will go from there. Also check things like brakes to make sure they don't have excessive drag, and that you lube your chain about once a week.

 

98 Honda accord. it just gets shitty city mileage hwy is fine. i only buy honda lol.

what is the stock gearing and how can i check?

i will check the choke, as i think that maybe why it always starts so easily. and the back brake is a bit weird, but i dont think it should be impacting the mileage this much. im planning on bleeding the brakes and replacing the pads after winter.

 

A wierd feeling back brake(spongy) could just be air in the system. As long as its not dragging excessively it wouldn't affect mileage. Put the bike on the center stand in neutral, the rear wheel should turn easily by hand. Good luck with the bike, I've only seen one 500 in person, they are beautiful machines.

 

yeah, it will spin. it just makes a little tiny bit of brake rubbing noise, but i think the rotor is slightly warped. and i know it needs to be bled, after winter im going to bleed the brakes and the clutch.

 

My 500 used to get really shitty mileage but when I put 85 carbs on it and sent them to billy Carr it gets around 210 to a tank and that's with aftermarket gearing. And the stock gearing is 15F 43R. M

 

i am not familiar with billy carr.

 

+1 on the choke and also I would check the air filter. Your really not too far off on mpg though. My 500 got low to high 30's with the stock gearing. That Katana is air cooled, lighter and less powerfull than your bike so it wil get way better mileage.

How many miles are on your bike?

 

actually, the kat is heavier and more powerful + bigger engine. and my bike has 25k miles on it.

 

Ah I was assuming it was a gs500 you were talking about

 

ok, so it may be from the back brake sticking. the right side pad on the back brake is always in contact with the rotor making the wheel not spin very far when i push it. any idea what i can do to correct that? its also clear that im going to need to replace the pads on that brake as the right one is about 3x more worn from this. im sure something is probly slightly bent as this bike has been down a few times. Also, i havnt ruled out the choke as the main problem, but this just concerns me more.

 

Tinkerin is right, if the rear brake were the issue, it would be very difficult to turn the rear wheel by hand. Follow the leads on the choke, make sure the air filter isn't clogged, the plugs are good, and the oil doesn't need changed.

 

well, the pad that's touching is a lot more worn out then the side that is free. also the rear wheel makes that screeching brake noise when i spin the wheel, or ride for that matter. i haven't ruled out the choke yet, but this was easier to get at. since i have to remove the front fairing to get at the adjustments. ill try to get a clear picture of the brake tomorrow.

 

The rear brake could be in need of a cleaning and greasing. Stick a new set of pads on it and grease the caliper slides, that should take care of your uneven wear problems.

 

caliper slides? do you mean the pistons? i think i need to replace the rubber pin boots that hold the caliper in place.

 

How many pistons are in the caliper? Most of the vfrs use 2 or 3 pistons on one side of the caliper and the caliper bolts are sliders that allow the caliper to center over the rotor when the pads wear. These slides can stick and cause uneven wear.

 

Rear brake caliper intel from the FSM: