KZ440 Speed / RPM / Gearing

I took my 81 KZ440 on the local highway for the first time.  I didn't feel comfortable going faster than 55mph because the bike was running at about 5.3k RPM.  Looking at Gear Commander it shows I should be running 60mph at 5.1k RPM.  Not sure if that's just theoretical versus real world difference, anyone chime in there?  To me its unacceptable I need to ride at least 65mph, I need to regear.  I live in a state where the interstate highways are 85mph - that seems a little frightening on a KZ440 (not so much with other bikes I've ridden though).  That means, according to Gear Commander, I'd need to run a 32T rear to achieve 85MPH at the same 5k RPM range.  That seems quite a bit ridiculous.  I don't think I'd have any fun riding a bike like that around town.  How many of yall have found Gear Commander for your kz440 to be pretty spot on with your real life riding?  What would be an acceptable RPM to sustain for hours on end on a 440 motor if I decide to go ride hours away (6hr being the most)?  I'm looking at moving to a 40T rear to achieve 65mph at 5k rpm.  Any KZ440 riders out there change up their gearing?

Maybe your bike's clutch is slipping.  Ed

Are you sure you are looking at the information for your exact model? In 1981, Kawasaki sold the 440B2 standard chain drive, the 440A2 LTD chain drive, and the 440D2/D3 LTD belt drive. I bet they are geared differently.

Well, slap me silly. The fsm says 45/15 for A and B models.

www.kzrider.com/modules/ServiceManuals/kz440.pdf

Yes, going to a 32 out back would be ridiculous, and would necessitate a shorter chain and it is likely that the chain would begin to hit the swingarm. I bet you would have to slip the clutch for a hundred yards to get going from a stop. Does yours in fact have 45/15?

EDIT: There is a lesson here—- check your sources before opening your pie hole, or pecking the keyboard. 

Not saying this is your issue, but what are you using to base speed and RPM results?  It could be that the stock speedo and tach are not as accurate as one would wish them to be. 

Please search KZ440 gearing..... there's some more good info there.

wrote:

Maybe your bike's clutch is slipping.  Ed
 

What makes you say that?

wrote:

Are you sure you are looking at the information for your exact model? In 1981, Kawasaki sold the 440B2 standard chain drive, the 440A2 LTD chain drive, and the 440D2/D3 LTD belt drive. I bet they are geared differently.

Well, slap me silly. The fsm says 45/15 for A and B models.

www.kzrider.com/modules/ServiceManuals/kz440.pdf
 

Yup 15/45.  I've always felt first gear was too short,  I feel like I'm changing to second waayyy too early.

I know I can use a phone to measure GPS speed.  What other way could I measure RPM?

wrote:

Please search KZ440 gearing..... there's some more good info there.

 

I'm not finding anything within the forum or by google search of the forum.  But then again, I've never used a forum with this type of format, so it could be my problem

SteveKing84 wrote

I should be running 60mph at 5.1k RPM

I would say that sounds about right. My 750 is  at approx 4700rpm @ 100kph (60mph) with a slightly bigger than stock rear sprocket  and I would be comfortable doing that all day.

I would guess maybe 7000 + rpm  to get me to 85mph (137kph). Would I do that hour after hour for up to 6 hours? I think not. That would mean running the motor continuously at say 75% of redline.  Would I do that on a kz440 ? No way. I would think that if I wanted to cruise at 85mph hour after hour I would be looking at a big Beemer or a Wing.

Just my opinion but it would be interesting to hear from others.  The kz motor is tough, bulletproof say a lot of us but perhaps not totally indestructible.

 

wrote:

wrote:

Maybe your bike's clutch is slipping.  Ed

 

What makes you say that?

A slipping clutch could account for the higher than expected rpm at highway speeds.