Speed vs. rpm (speedometer fluctuation problem)

[scapello]

Can someone give me a quick speedometer readout at 4000 rpm in 5th. I am getting rather large fluctuations that are well within ticket range and I just want to make sure that I am in the right range.
I know there will be differences since I am running a 17" rear and so on but I am reading anywhere from 45 to 75 mph when running at 4000 rpm. Just trying to limit it somewhat before I can figure out how to dampen the speedometer to help with this.

Steffen

[andyb]

Remove the speedo cable, lightly lubricate it with grease, reinstall.  Unless the gauge itself is getting wonky (or the cable is about to break), this provides enough damping to solve the problem.

[jvb_ca]

Try this....http://autos.groups.yahoo.com/group/yamahafj/files/Gearing%20Info/

From Yahoo Groups files section.

Cheers...Jake

[mikeholzer]

I use lock lube on mine. It's a very light oil with graphite in it. I remove the whole cable, pull out the drive element, clean off the gunk (I like brake cleaner for this), spray out the casing, then re-install. I spray a little of the lock lube down from the top end and it flows to the bottom.

Lock lube is available at your local hardware store, or you can find it at locksmith shops, too.

Back in the day, you could pick up a tin of "special" lube just for speedometer cables, but I haven't seen that stuff for about 20 years. It was a type of grease with graphite in it; made one heck of a mess on your hands when you applied it! I guess that with the advent of electronic speedometers, there is less need for this.

FYI: on the freeway, high gear, 4000 rpm comes up at about 70 mph.

[scapello]

Thanks guys, I will try the cable lube and see if it helps.

Steffen

[scapello]

 

I have tried the lock lube, dry lube, Axel grease, WD40 and motor oil and I can make that speedometer read anywhere from 55 to 75 at 4000 rpm and settle it at anywhere in between. Cable looks to be in great shape, gauge seems to be in great shape.

The yahoo link does not work, was that also about lubrication?

Any other suggestions?

Steffen

[racerman_27410]

i think i have a known good speedometer around here somewhere... if i can put my hands on it and you want to try it.... its yours for the cost of shipping


KOokaloo!

[jvb_ca]

The yahoo link does not work, was that also about lubrication?

Any other suggestions?

Steffen

Linky fixed......
There is a couple of gearing/speed spreadsheets to calc speeds at rpm.

Chers..Jake

[scapello]

Thanks, the link works now. I have since driven by one of those active speed monitoring signs that show your speed when you go by and am close to the calculated numbers. I am still baffled by what would be causing this, the fuel gauge damping makes sense to me but the speedo behavior doesn't

Thanks for the offer racerman, I might have to take you up on that one but I want to play a bit more to see if I can fix this first.


Steffen