Speedometer error?

Well, took the 650 out on the freeway for the first time since the accident last August. Was kinda nervous but felt good and the bike ran and felt great. Anyway, I need to know what RPM's you KZ650 owners with stock gearing (16/42) are running at 70 mph. My old spedo (85 mph) showed 6000 rpms at 70 mph, my replacement (140 mph) now shows 5500 rpms at 70 mph. I'm just curious which one is or was off? I know these old spedos are not super accurate but just wonder which one is closest. Thanks guys...

I think your bikes original speedo was more optimistic than most. :blink:

My 650 purrs along at roughly 5K rpm's at 70 mph since the gearing change (17/42) I did a few years ago, and IIRC that knocked off 500 rpm's from what it originally was at any given speed.


BTW, does your toolbox have an open spot where something used to be? :laugh:

LMAO @ Chris!:laugh:

Did you FORGET something at Chris's place when you two were playing??:laugh: :laugh:

Sorry John...couldn't resist.:laugh:

John, I almost forgot.

I'm planning on taking a few of the broken Craftsman sockets I have in to Sears to get the FREE replacements.
Want me to break those pliers and get you some ones while I'm there? :laugh:

RetroRiceRocketRider wrote:

John, I almost forgot.

I'm planning on taking a few of the broken Craftsman sockets I have in to Sears to get the FREE replacements.
Want me to break those pliers and get you some ones while I'm there? :laugh:

Phoning Sears now,to fink on you!:ohmy:

Nope, not mine Chris! I guess there yours now, unless someone else pipes up. Those are good pliers too!

So, sounds like my new spedo is doing the right thing. That means I was probably going 75+ before. I'll see if any other 650 owners confirm this, Thanks Chris.

Mine was around 5500 RPM, but it was also a tad lean.

Bluemeanie wrote:

Well, took the 650 out on the freeway for the first time since the accident last August. Was kinda nervous but felt good and the bike ran and felt great. Anyway, I need to know what RPM's you KZ650 owners with stock gearing (16/42) are running at 70 mph. My old spedo (85 mph) showed 6000 rpms at 70 mph, my replacement (140 mph) now shows 5500 rpms at 70 mph. I'm just curious which one is or was off? I know these old spedos are not super accurate but just wonder which one is closest. Thanks guys...

My 750 came with stock gears of 16/38 and spun 5k at 70 MPH, so a 16/42 set would be in the 5500 RPM ballpark.

RetroRiceRocketRider wrote:

John, I almost forgot.

I'm planning on taking a few of the broken Craftsman sockets I have in to Sears to get the FREE replacements.
Want me to break those pliers and get you some ones while I'm there? :laugh:

I have a squirrely torque wrench you can beat on the pliers with so I can get a new one...

I was out on my B1 yesterday. Stock speedo and stock gearing.
6K RPM @ 70MPH

dont forget tire size will change the reading by a few.