Little help on troubleshooting poor fuel economy

Friends-

I'm trying to hunt down the source(s) of the poor fuel economy that I'm getting on my '82 KZ550.
I should be somewhere in the 50mpg range, but I'm actually getting in the upper 20s. This isn't a 1 time deal, I've been tracking this a while. I added a screenshot of the app I'm using to track consumption.




What I've done is a complete carb clean, sync, new plugs, new vacuum hoses, adjusted the idle to spec and did a full gasket and O-Ring replacement on the fuel cap. After the work on the gas cap I jumped to 37mpg but that's still 15 under what it should be. I do have the rebuild kits, but I'd prefer that as the last resort.

What I'm looking for is suggestions of other things to check next. I'm new to motorcycles and carburetors in general, so my troubleshooting skills still somewhat are limited.

Thanks!

thoraxotool wrote: What I've done is a complete carb clean, sync, new plugs, new vacuum hoses, adjusted the idle to spec and did a full gasket and O-Ring replacement on the fuel cap. After the work on the gas cap I jumped to 37mpg but that's still 15 under what it should be.

That's about what my 750 twin gets in all city driving.

If your compression is good, timing and timing advancer is working right (no coil/plug problems) then it has to be the carbs.

Is the spark plug color too dark (rich)?

Check for gas loss out the overflow pipes. watch for gas on the ground under the bike.

If not already done, would also verify that the float valves aren't leaking.
And would also perform the clear tube test to confirm fuel levels are within specs.

Good Fortune!

Timing is correct, the advance is also right on. I haven't checked compression but since I can get to almost 50mph in 3rd, I suspect that it's OK.
I don't (nor have I ever) seen gas spilled from the tubes. I used to smell gas a lot before I cleaned the carbs, now I don't.

The spark plug wires are of unknown age, though they show spark. I'm not sure though what exactly "acceptable" is on the strength of the spark. I've considered getting new wires just because of their age. I wonder how much effect old wires can cause?
My plugs were normal on 1 & 4 and ashy on 2 & 3 when I cleaned the carbs, now all 4 seem to be the same color that 1 & 4 were.

I forgot to mention that I replaced all four intakes boots and clamps. I've checked for air leaks and can't find any now.


If I need to rebuild the carbs, I do have the kits.

@ Patton: I'll check that in the morning when I can actually see. Thanks for the tip!
Thanks!

Do you want the real answer? Well, I'll give you my opinion. In the USA? Why is there 20 blends of gasoline?
Why is there 10% ethonal? Me and you can take any vehicle and cross the country, stop at any gas station and get "GAS" right? Well the EPA and the DOT and the pussified, liberal, socialized hippies tell you this!
Fossil fuel is bad! Your evil! you use gas! F U! Your carbon foot print sucks! Motorcycle man!
All the while prez, bro ham runs 2 - 747 jets and 5 C 130 transports to deliver his 20 car fleet of armor plated 10,000 pound caddi's that get 5 mpg's, while he plays golf in California's Drought laden golf course's with ther green grass. And Fat ass Al gore drives his 1 passenger Lear jet around. But your evil! for burning gas!
Last time I was in school, I learned the earth is round. And there were 7 layers of atmosphere!
So China, South America, Mexico still use leaded fuel, etc. And factories the other side of Brownsville Tx, spew tons of chemicals into the air! People in china walk around with paper respirators. So, what the fuk?
So it must be us in america riding motorcycles, that are polluting the whole earth.
So maybe when all the idiot, dumb ass americans get a clue and pull their left wing mainstream media heads out of their ass's. then maybe someone will get a freakin clue. The earth is a spherical globe! and shit rolls down hill in an infinate line, and the line never stops.
So go bake one and figure this out
There take that opinion, and don't exhale too much CO, you might cause more global warming

Oh by the way, my 2012 ford F 150 6 banger is getting 10.6 MPG's. And oil speculators on wall street have driven oil up to $105 a barrel, because gas is to cheap in the USA, they say!
And our largest export is OIL??? Keystone pipeline???? No? it's evil? Crips & bloods = Dems =Repubs Gangs, Gang freakin members. Gangs taken care of their members.
That's all it is! Gangs!
Where's RICO when you want it?

So, how's your gas milage again?
I went on a tangent!
Gasoline.

I'm a cheap SOB, so I like to get maximum fuel economy on all my rides. The less I can pay at the pump, the better. I'm getting about 30mpg at the moment, I'd rather get north of that.

Kind of funny, though. I work in oil and have access to gasoline without ethanol
But honestly, don't even get me started on the oil industry. Being on the inside, I get to hear a whole lot of stuff. That whole Bakken thing is a headache in itself. Oy.

When pushing your bike around the garage, does it roll easy? If not, then that's where your gas mileage went. Bearings, sticking brakes, low tire pressure, bad chain, all may add their part to the problem.
And then there's riding style,

Original air box? Original pipes?

The gas has to be going somewhere. You can get the state of tune off center and then you end up riding with the throttle wide open all the time to make enough power.

So...

I can roll the bike with no issues, but I think there might be a slight brake stick. I will futz with it this weekend.
I replaced the chain, sprockets, air filter, spark plugs, pads and tires within the last 1000 miles. I matched OEM teeth and chain pitch. The airbox and pipes are all stock. Hell, other than the new grips, the machine is damn near 100% stock.
I'm not an aggressive rider, but I do find myself speeding frequently. I'll lay off the throttle some and see what comes of that.

Now, some things that I'm sure affect the economy I cannot change. At 32, I don't think Ramona will ever match her peak. That's OK and to be expected.
My job is at sea level and my house is at nearly 500'. That daily elevation change isn't going away. I do have the option of finding a less hilly route, that will be investigated.
Also, I think I could stand to lose about 30 lbs...

I've done a couple days' worth of trolling the nets, and I will be using what I learned as well as your tips. Since I got the kits for free, I'll be rebuilding the carbs, replacing the crankcase vent as well as the last bits of vacuum hose that I haven't gotten to yet.

I'll report back once I've dome some more work.

Thank you all again!