- Posts: 15
- Thank you received: 5
Little help on troubleshooting poor fuel economy
- thoraxotool
- Topic Author
- Offline
- User
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.
Attachment Screenshot_2014-02-23-19-50-12.png not found
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!
1982 KZ550 LTD
Please Log in or Create an account to join the conversation.
- bountyhunter
- Offline
- User
- Posts: 7246
- Thank you received: 337
That's about what my 750 twin gets in all city driving.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.
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)?
1979 KZ-750 Twin
Please Log in or Create an account to join the conversation.
- bountyhunter
- Offline
- User
- Posts: 7246
- Thank you received: 337
1979 KZ-750 Twin
Please Log in or Create an account to join the conversation.
- Patton
- Offline
- KZr Legend
- Posts: 18640
- Thank you received: 2098
And would also perform the clear tube test to confirm fuel levels are within specs.
Good Fortune!
1973 Z1
KZ900 LTD
Please Log in or Create an account to join the conversation.
- thoraxotool
- Topic Author
- Offline
- User
- Posts: 15
- Thank you received: 5
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!
1982 KZ550 LTD
Please Log in or Create an account to join the conversation.
- z1kzonly
- Offline
- User
- Sustaining Member
- Posts: 2892
- Thank you received: 542
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
Livin in "CheektaVegas, NY
Went thru 25 of these in 40 yrs.
I SOLD OUT! THE KAW BARN IS EMPTY.
More room for The Old Girl, Harley 75 FLH Electra Glide,
Old faithful! Points ign. Bendix Orig. carb.
Starts everytime!
Please Log in or Create an account to join the conversation.
- z1kzonly
- Offline
- User
- Sustaining Member
- Posts: 2892
- Thank you received: 542
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?
Livin in "CheektaVegas, NY
Went thru 25 of these in 40 yrs.
I SOLD OUT! THE KAW BARN IS EMPTY.
More room for The Old Girl, Harley 75 FLH Electra Glide,
Old faithful! Points ign. Bendix Orig. carb.
Starts everytime!
Please Log in or Create an account to join the conversation.
- z1kzonly
- Offline
- User
- Sustaining Member
- Posts: 2892
- Thank you received: 542
I went on a tangent!
Gasoline.
Livin in "CheektaVegas, NY
Went thru 25 of these in 40 yrs.
I SOLD OUT! THE KAW BARN IS EMPTY.
More room for The Old Girl, Harley 75 FLH Electra Glide,
Old faithful! Points ign. Bendix Orig. carb.
Starts everytime!
Please Log in or Create an account to join the conversation.
- thoraxotool
- Topic Author
- Offline
- User
- Posts: 15
- Thank you received: 5
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.
1982 KZ550 LTD
Please Log in or Create an account to join the conversation.
- steell
- Offline
- User
And then there's riding style,
KD9JUR
Please Log in or Create an account to join the conversation.
- bountyhunter
- Offline
- User
- Posts: 7246
- Thank you received: 337
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.
1979 KZ-750 Twin
Please Log in or Create an account to join the conversation.
- thoraxotool
- Topic Author
- Offline
- User
- Posts: 15
- Thank you received: 5
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!
1982 KZ550 LTD
Please Log in or Create an account to join the conversation.