TOPIC:

Should I be getting 180kms( 112 miles) (before reserve) to a tank on my 77 Z650?
If not, what should I check? Ignition timing is factory, have Dyna ignition and coils. Power seems good, although I have only ever ridden this 650.

Regards, Andrew.

I usally get about 130 mpg on my 77 until I hit reserve.
IIRC, that's filling it up on the sidestand.

Your mileage may very.

I get between 30 to 40+ miles per gallon with my bike that is slighty modified.Then again it depends if I am highway riding or stop and go in the city.

I'm getting 200 km/ 124 miles on my 650 before I need to switch to reserve. There was a post earlier, and this seemed to be low. My plugs are black, and I have done the Coil Wiring Mod. My bike runs strong, with no missfire or bogging. I'm thinking of lowering the neddles in the carbs one notch and try that for a while.

Post edited by: rstnick, at: 2006/04/24 20:06

I have a B model with the Mikuni carbs that have the idle adjuster screws at an angle on top of the carbs.
I have thought about lowering the nedles a notch, however I was getting slight detonation in top gear/ full throttle when it was very hot last summer. But then, maybe I can live with not hammering it on hot days and change down a gear or two if I need to.
I would like to ick up some more economy, mainly to increase range, but if running the engine abit rich wil help keep it alive, I am not going to pursue it!
I've also just gone from a 130/65 rear tyre to a 130/90 and dropped 500 rpm at cruise, so we'll see how that goes I guess.

Regards, Andrew.

My bike is stock except for the air filter and electronic ignition. I'm getting 44mpg and can go at least 160 miles maybe 170 before reserve.

I get 160 miles before hitting the reserve. I get exactly 40 MPG at 90 MPH. My 650 has the 720 big bore kit, pipe and pods.

Andrew, consumption is not just a factor of the bike's settings/mods. What do you weiggh and do you carry a passenger/ The next pertainent info is, are you going hot off of the line each time at a lite? Even a little fun cuts the average. Check your plugs for color and that will tell you more about the bikes using fuel compared to your using fuel based on the way you ride.

Yeah, that is true. I do ride a hilly road to work, maybe I am expecting a bit much in th eway of economy.
I am a pretty big bloke, 6'1 tall and about, well, 260 lbs or so! Tall in the body too, so a bit of wind drag I suppose.
I don't know if jetting is stock either, the bike had a 4 into 1 exhaust and pods when I got it, so maybe someone before me has played with things, or maybe they just replaced old OEM parts that broke.
Plugs have a nice dark tan colour on teh porcelain, with black fluff around the threads.
I don't really hammer it off the line, usually change at around 3000rpm tops and cruise at 4500 rpm to work.

Regards, Andrew.

I just ran my bike till it died yesterday and it was at 125 miles before I had to go to reserve.But I ride double alot in the city and my plugs are REAL dark still as for I am still trying to get the carb jetting dialed in.

As for your plugs being sooty around the edges that is the low end (idle/choke) circuit.If you run it on choke to long this will be aparent.

i've thought that something was up with my '78 KZ650 B2 for a while...and this thread confirms it.

i get 25 mpg average, and have to go to reserve at 80-90 miles.

everything on the bike is stock, from what i recall.

i'm 165lbs and don't ride too hard. i'll cruise on the highway at about 70mph, usually at 5000-6000rpm.

i haven't noticed anything specifically unusual about the engine. it starts right up with the elec start, mostly with the choke on, but i close the choke before i ride away. it generally has good power when accelerating. sometimes, however the engine will hesitate when i open the throttle wide from idle...often when the engine is cold. i'll get some smoke when i rev the engine while in neutral. not really black or white smoke...and it's not terribly thick, but it's noticeable and bluish.

i'll pull the plugs later and see what condition they are in and report back.

i don't mean to hijack this thread, but can anyone offer suggestions of things for me to check to get my fuel economy up to "normal"?

regards,
-bt

BT, probably the best place to start is the plug test. Does your bike smoke? Are there any leaks elsewhere? My vacuum petcock is giving up after being rebuilt two years ago so I think I'll replace it with a Pingel for about five bucks more than a rebuild kit.

I'm getting just around 40 MPG on my SR which isn't too bad considering I weigh around 250 pounds myself and am about 5' 10" and there is no windshield on the bike. At an indicated 65 MPH the tach shows 5400 RPM. I guess I should get an electronic tach to figure out my tach error like I did the speedo error with my GPS.

- Nate >>