How I Re-Tuned My KZP For Better MPG

I know this is wrong. It's not what a guy is supposed to do but I actually knocked a few ponies off my 2002 11,000 mile KZ1000P in order to increase my riding range of the pitiful 4 gallon fuel tank as I want to use the KZP as a long distance tourer.
First off, I take NO credit. My thanks goes out to member OTAKAR. Without Otto's help and his expert knowledge of the Mikuni BS34 carbs I would still be wandering the countryside in search of a gas station every 100 miles.
As for my own expertise, I am no dunce with a wrench but my carburetor rebuilding experience is limited to dirt bikes (back in the day), lawn mowers and recently my snow blower which took 10 minutes. After reading and hearing first hand stories of people who took perfectly running bikes and getting into the carbs only to never have those bikes run properly again had me scared. The internet is full of such tales of woe.
Long story short. On Otto's instruction, I re-jetted the carbs, slapped them back on the bike, started it up and drove off (running perfectly) wondering what was the big deal in the first place.
Here is what I did:
OEM main jet 127.5 changed to 125
OEM pilot jet 37.5 kept the same
OEM needle jet Y-1 kept the same
OEM jet needle on the police bike is a rich non-adjustable 5GN45 changed to a 5FL51
I also changed my stock gearing from 17/46 to 17/42 to knock down the RPM on the highway. It went from 15.5 MPH/1000 RPM to 17 MPH/1000 RPM

On combination highway/twisties/cruising trips my overall gas mileage went from 32-35 MPG with a high of 39.4 to (after mods) 41-48 MPG with a high of 50.8
My reserve comes on at 143 miles instead of not much over 100.

My intention was to get greater range per tank without altering the bike. Higher gas prices don't sting as much either. Where my main jet has remained about the same, WOT feels unchanged. Small throttle openings on, say, taking off from a red light is no problem. Plugs show no overly lean condition. I would not recommend gearing any more steeply than I did. If I want quick highway acceleration I now have to kick it down a notch.
Hope this info helps. And thanks to all who helped me.

Sounds like you got the gearing just right for your riding.

I took a practical approach. The bike does not seem busy at highway speeds. I'm not crazy about the way it feels above 90 anyway.

Got any ideas on how to improve a shaft drive? I'm changing the exhaust, so I'll have to rejet anyways, but I don't have any sprockets to change. Guess when I get mine all back together, I'll see what kind of mileage I get to start off with.

Chaotic Reason wrote: Got any ideas on how to improve a shaft drive? I'm changing the exhaust, so I'll have to rejet anyways, but I don't have any sprockets to change. Guess when I get mine all back together, I'll see what kind of mileage I get to start off with.

I did check my mileage after the re-jet but before the sprocket change. It didn't change much. I mainly did the sprocket change as I am mechanically sympathetic and wanted to calm down the engine on long highway rides. It was with the gearing change that I noticed the difference in acceleration. I would not sweat not being able to change the final drive ratio. Oh, I just looked at your bike in your signature. My jet needles were from an '81 CSR1000. My police engine was converted to civilian specs.

I'm not too worried about the loss of acceleration, I'm more of a cruising kinda guy. I figure I'll get there when I get there, and if I need to get there sooner, I should probably leave earlier.
Thanks for the heads up though. Guess I'll see what my MPG is like when I get her all back together, and then go from there.

Chaotic Reason wrote: Got any ideas on how to improve a shaft drive?

A buddy of mine just bought a Honda Pacific Coast. It seems a rear drive from a larger displacement Honda model with a lower numerical gear ratio will fit it. Maybe the same can be said for your situation.????

On my 1075 engine with andrews 3X cams my bike got between 48 and 52 mpg. I check my fuel mileage every fill up. That is with pods and open header.Jetted 40/140. Roy

roy-b-boy-b wrote: On my 1075 engine with andrews 3X cams my bike got between 48 and 52 mpg. I check my fuel mileage every fill up. That is with pods and open header.Jetted 40/140. Roy

I have heard similar stories before and I am envious. I have that big honking faring however. I'm a sport bike type but I'll tell you, that faring and floor boards come in handy on a long trip.

I have heard similar stories before and I am envious. I have that big honking faring however. I'm a sport bike type but I'll tell you, that faring and floor boards come in handy on a long trip.[/quote]


Amen!

I'm building a touring bike out of a 1987 KZ1000-P6. It was given to me in pieces by my step-brother, who abandoned it mid-rebuild when he buggered a couple pistons during reassembly. I picked up the block & pistons from an 1100 Spectre, easy fix/upgrade. Conventional wisdom dictates that you want a big, under-stressed engine for a touring bike, right?

I'm planning a road trip next year, a big one! 10,000 miles, give or take. This will take me from central Oklahoma through the mountains of northern New Mexico to the Grand Canyon and Vegas to Oakland, CA, up the PCH to Seattle, down to Denver, then Chicago, PA, CT, RI, MD, VA then Deal's Gap and Nashville before heading home.



Looking at that many miles, fuel economy becomes crucial.

Assuming gas averages $3.50/gal...

10000 miles
35 mpg =
285 gal
$997.50

10000 miles
40 mpg =
250 gal
$875.00

10000 miles
45 mpg =
223 gal
$780.50

A couple hundred dollars saved on fuel could make a difference in how comfortable I am along the way, like could I rent a motel room instead of trying to set up camp in the middle of a huge storm? Could I get a nice sandwich at Subway, or would it be MREs again?

Anyway, good to know about the needle and down-jetting! I'd already planned to gear the final drive taller, like I did with my 750, but I'm looking for every advantage I can find to strike the ideal compromise between performance and economy. I want it to get good gas mileage... for an 1100.

Something else I'm pondering, and maybe I should start another thread for this, but what other, larger tanks will fit this frame? I'm guessing the '82 GPz1100 tank ($$$!)

That is the type of trip I plan to take with my KZP. I did one on my ZRX1200.
There is a larger gas tank which will fit but which one eludes me right now. It bends the seat up a little though. There is also a company that make spare gas containers for ATV's. It is slim, strong plastic, holds a gallon and will fit in your side box. I can look it up if you want. I can't recall it's name either as I no longer have the need for additional fuel with my increased MPG. I think it is a good idea to get off the bike every 100-125 miles to stretch and walk around. A gas stop in this range fits the bill.
Stock gearing was 17/42. I went to 17/46. It was here that I felt the biggest change to the bike. While there is ample acceleration and much reduced highway vibes, next time I would go with a 17/45 or an 18/42. With the 17/46 I am turning 4500 RPM at 75 MPH. I definitely would not go steeper than 17/46.
Make sure your suspension is up to snuff as well as the extra weight you are carrying may cause some hairy nandling.