Looking to extend Mileage and lower RPM 83KZ1100

II bought this bike recently mostly for cruising with some longer trips in mind... 5 to 600 miles one way. I have rode the bike for about three tanks of fuel about 250 miles... Bike has Star header ( with heavily modified LOUD baffle) Sounds cool in the city. It also has Complete dyna ignition coils included. Some type of Pod filters. I don't see a brand on them. Not concerned with light to light speed. Bike has averaged 28.9 miles per gallon in three tanks. I can defenitely tell its running rich (Plugs are dark) . Previous owner couldn't remember jet sizes. As I have posted before it is at 5500 rpm at 70 mph. From what Ive read in other posts that's close to 1k higher than some with same bike. I've also read that final drive ratios between 1000 and 1100 were different and will interchange. I love this bike it runs GREAT looks Great and even sounds Great (other than on highway) Will a 140 tire fit this bike ? If so how much rpm difference am I looking at ? Has anyone changed the final drive ratio ? I had a 82 KZ1100 years ago that was completely stock with fairing and got 40 mpg. Like I said looking to cruise a little more and not looking to forward to stopping every 80 miles to fill up..lol I know this is a lot of questions but if anyone has answers to any of the questions Id love to hear them.

One more question ... Wanting to check float level before messing with jetting so I'm sure my rich condition isn't from improper float height. I briefly looked at float bowls is there a homemade type fitting that you make to use clear tube float check or is it available on ebay etc ?

I'd quiet the baffle first, then lean out the carbs. As for the drive, I'd have to defer that to others that know more about it. Coming up here today, I was at 5000 and 80 MPH.
Steve

My stock 750 twin spun 5K @ 70 mph, so I changed the gearing to take it down to 4200. Reduced noise and vibration, did NOT increase mileage. Even though the revs drop, you have to open the throttle more to get power to pull the higher gear.

76KZ900 wrote:
One more question ... Wanting to check float level before messing with jetting so I'm sure my rich condition isn't from improper float height. I briefly looked at float bowls is there a homemade type fitting that you make to use clear tube float check or is it available on ebay etc ?

I kluged one up by "tapering" the end of a piece of tubing with a razor blade so I could cram it into the carb drain hole.

You can heat it, then screw it in to make threads.
Steve

Thinking all the 80's KZ1100 drive-shaft gear ratios are the same, otherwise there would be known-options available to choose from.
At 70mph, my engine is turning 4400-4500 rpms in fifth gear, with a mu90 16 tire on the back, and mm90 19 on the front.
Perhaps your tire sizes are different, or your electric tach/speedometer system is giving false readings.
My speedometer shows sixty five or so, when I am actually moving at 70 mph according to a GPS unit mounted on my bike, so I question the accuracy of the factory gauges.
The only practical(?) option would be to change over to chain-drive, but when considering the cost/value ratio, those thoughts tend to fade away...especially considering the smooth ride and maintenance advantages we already have.
Ride-on!

daveo wrote: Thinking all the 80's KZ1100 drive-shaft gear ratios are the same, otherwise there would be known-options available to choose from.
At 70mph, my engine is turning 4400-4500 rpms in fifth gear, with a mu90 16 tire on the back, and mm90 19 on the front.
Perhaps your tire sizes are different, or your electric tach/speedometer system is giving false readings.
My speedometer shows sixty five or so, when I am actually moving at 70 mph according to a GPS unit mounted on my bike, so I question the accuracy of the factory gauges.
The only practical(?) option would be to change over to chain-drive, but when considering the cost/value ratio, those thoughts tend to fade away...especially considering the smooth ride and maintenance advantages we already have.
Ride-on!

I had read on another forum that the shaft 1000's were different vs the 1100, Something like 2.29 vs 254 or 245 on 1100. I don't think that would make that much difference though. And of course its been like trying to prove bigfoot exists...lol I thought maybe taller tire would be way to go, I'm going to GPS my bike on my days off but based on traffic speed I'd say my speedo is reading low if anything.

Anyone use www.gearcommander.com ? Have the results been consistent ? It shows my bike with factory gearing should be 4126 rpm @ 70mph not the 5500 that its at...

Checked speedometer today with gps. It's dead on..

I read that shaft kz1000 had 2:29.1 final drive ratio.. My 1100 is supposed to have 2:54.1 .

Anyone that's smarter than me at math.. Which should be 90% of you at least.. Can you tell me the difference in rpm that would make ? Like I said I went to the gearcimmander.com page but although data looks right to me it's coming out way lower rpm than I'm running. So maybe I'm not smart enough to read websight right

That gearcommander.com link doesn't work for me.

The link works for me but I don't know what to look for. DO YOU HAVE A FACTORY MANUAL? It may be possible someone changed the gearing to compensate for the lack of power being it's a shaft drive. It might be in the final drive or transmission gears.
Steve

76KZ900 wrote: Checked speedometer today with gps. It's dead on..

I read that shaft kz1000 had 2:29.1 final drive ratio.. My 1100 is supposed to have 2:54.1 .

Anyone that's smarter than me at math.. Which should be 90% of you at least.. Can you tell me the difference in rpm that would make ?

It would be:

2.29/2.54 = 90.2%

So whatever your RPM is now, multiply it times 0.90 and that's what it will be with the 2.29 gear.

swest wrote: The link works for me but I don't know what to look for. DO YOU HAVE A FACTORY MANUAL? It may be possible someone changed the gearing to compensate for the lack of power being it's a shaft drive. It might be in the final drive or transmission gears.
Steve

I only have the owners manual under seat for now. I just checked it.. And I must have had a dyslexic moment..
My owners manual states final drive ratio 2.454.. Not 2.54..
I'm def not getting into transmission but final drives for kz1000 , with the different gearing are less than $20 on ebay so that may be worth a try..
So far I'm at a half tank of 55mph riding where I would normally be on empty riding at 70mph. So it seems to have helped lowering rpm's.

If anyone has a kz1000 shaft manual and can confirm that number for final drive ratio of 2.29 id appreciate it.