Airhead Gas Mileage

[kneedrachen]

Just bought my first Airhead, an '86 R80RT, i filled the tank for the first time, it took just over a gallon, so obviously it was near full. Took it on some back roads and then out on the highway, as I was nearing my exit it was sputtering so it seemed like a fuel issue. I flipped the petcock on to reserve, which seemed to remedy the problem, however this happened at 87 miles on the tripmeter, never exceeded 66 MPH. The new fuel line and fuel filter installed by the previous owner are clean, and i'm sure the fuel in the tank is old. Any ideas? Or am I destined to have poor gas mileage?
Thanks In Advance,
Alex

[Stuff2C]

40+ is what you should expect, depending on how you ride. I have a 86 R80RS (homemade RS) and get 40 to 45 depending on how i'm feeling that day :D Clean the filter in the tank on the petcock.

[kneedrachen]

stupid n00b question as I haven't read that far in the clymer manual yet, is there a filter in the tank itself? :dunno

[Stuff2C]

on top of the petcock...you can't miss it when you take it out :thumb
If one side is clogged you can only use half the tank.

[kneedrachen]

Got it, thanks for your help!

[Isamemon]

if you find your in tank filter is indeed bad (dirty) I would pull the tank and slosh it around and rince it out, you might have goo in there too that will just settle and plug the clean filter again

[37071]

If you find the filter is plugged; check to see whether there is rust in the tank, and whether the tank lining is peeling off. Good Luck

[kneedrachen]

thanks gang, will update as i progress through this, just haven't had time as thanksgiving has pushed other things (likes bikes aside :banghead ) damn in-laws. . . :bolt

[pmdave]

Obviously, drain the tank and look around inside with a flashlight. If the brown liner paint is falling off, you'll need to do some serious cleaning and "cream" the inside.

Assuming the tank is clean and the brass screens clean and in correct position, be aware that the tank cap can also be a culprit. The tank needs a vent to allow air to enter as the fuel is used. Some tank caps don't vent correctly. The symptom is the engine starving for fuel, and when you open the tank cap to check, there is a little "whoosh". And when you try to restart the engine, it runs normally.

Next time it stalls, listen for a "whoosh" as you open the cap. I'll take a photo of the correct location to drill a tiny hole in the cap.

pmdave

[pmdave]

The hole is 1/16" and just goes through the aluminum cap (1/4" penetration will do)

[osbornk]

I've had my 86 R80RT a little over 8 years and the worst mileage I ever got was around 45 and I get between 50 and 55 on slow roads such as the Blue Ridge Parkway (about 45 miles down the road). I only open 1 of my petcocks and I generally go between 160 and 200 before I need to open the other one or go to reserve.

They are good and solid bikes. In the 8 years I have had mine, other than tires and normal maintenance, I have replaced the battery once and one fork seal. I have about 50K on mine. I had both it and a 92 K75RT for 7 years and decided to sell one. Even though the K75RT did everything better than the R80RT, I kept the old one because it had a personality.

[crazydrummerdude]

I only open 1 of my petcocks and I generally go between 160 and 200 before I need to open the other one or go to reserve.

Why?

[MichiganMike]

I've been getting about 37 to 40 MPG on this bike since I purchased it this last spring. What's the consensus on best operation of the petcocks? I normally just use the left one as that seems convienient. Before this first snowstorm here in Michigan I used both and reserve on both sides to see if
it made any difference. Didn't notice anything different. Any fast and hard rules I should be following?

:usa

[widebmw]

I run both sides on. When I go on reserve I turn the left side to reserve, then when traffic is clear I turn the right side to reserve.
The reason is I don't like it when there is no power.
Every time you switch from one to the other it is because you are out of gas and you don't want the traffic behind you to catch up while you are switching from one side to the other, to first reserve then second reserve.

It's all the same amount of gas.

[willard]

Mileage is between 47-52 - - depends on speed. You ought to get a little less because of additional displacement. bb

[osbornk]

Why?

I only open one petcock for a couple of reasons. One reason is I like having an extra reserve because I live and ride in the sticks. Mainly, it's easier to remember to turn off the one. With my prior K75, K100, Honda Magna and Goldwing, I didn't have to turn on a petcock and got out of the habit. I had both the K75 and the R80 at the same time for 7 years and I kept forgetting to turn it off. I pick up my new to me K1200CL next month so my forgetfullness may return.

[Isamemon]

if your scooter does not run well on only one petcock its a good bet that the petcock filters are yucky
otherwise, I like the dual petcocks and running one at a time when low, it is like a double reserve
rest of the time I run em both open

and while were on that subject, I recomend in line filters between the petcock and the carbs
I know many of you do too
its that one little pinch of filtering thta might keep you from pulling your bings apart on the side of the road, in the dark and in the rain
been there done that

[kneedrachen]

as a side not, just like to say i'm pretty proud of myself my first post turned in to a two pager. . . :type

[The_Veg]

If you use in-line filters, make sure that they allow sufficient flow. You want at least 125 ml/15 seconds. This is a simple test to do- just find a container with ml graduations, hold it below the bottom end of the fuel line (disconnected from the carburettor), and open the petcock for 15 seconds.

[osbornk]

if your scooter does not run well on only one petcock its a good bet that the petcock filters are yucky
otherwise, I like the dual petcocks and running one at a time when low, it is like a double reserve
rest of the time I run em both open

and while were on that subject, I recomend in line filters between the petcock and the carbs
I know many of you do too
its that one little pinch of filtering thta might keep you from pulling your bings apart on the side of the road, in the dark and in the rain
been there done that

Mine had the in line filters when I got it 8 years ago and I've never had any problems running with one petcock open. A prior owner might have taken the petcock filters out. Never had any reason to look.