speedometer question

So I just failed my inspection after months of work (new paint, polishing engine cases, tires, carbs, dyna ignition, valve clearances...the list goes on) I thought I had everything inline... BUT the mechanic came back from the test ride to tell me that my speedometer works great except it won't go past 45 mph... :huh: Since it wasn't inspected I had only ever had it out around the block at speeds less than 45 so I had no idea. Good news is that he had it out on the highway passing people (so he was at least at 60 or so) with no problems other than the speedo. So my questions are #1 what may be the problem, and #2 how do fix it. Could it be the speedo gear at the wheel, or is it in the gauge itself. I know I can find plenty to replace it with but would rather fix what I've got. Anyone have any insight or experience with this? Any info would be greatly appreciated.

I might just be the cable. You can remove the inner cable, clean, and lube it to see if that helps. Otherwise replace the cable and see if the problem goes away. Ed

I have the same problem on a 440, but it begins at 55mph. In my case, I believe it to be cable routing, since the 400 fork ears that I used require a significant bend in the cable in order to clear the headlight housing that is closer to the forks than it should be. Fortunately, there are no inspections required here. That's a long way of asking: Did you alter the cable routing?

Thanks, I'll check the cable out, I didn't look too closely at it, figuring that it works good until 45 so it should still work good past it... :blink:

I didn't alter the cable routing, but that doesn't mean the PO didn't, but then it never looked odd... I'll check it out just to cross that off the list.

Thanks guys.

You've probably got an inner cable that's made up of twisted steel wire, sometimes they will get a strand loose, limiting the rpm's to the speedometer or tach. I'd do this: remove the cable from the bike at both ends, seperate the inner from the outer cable, looking for signs of a loose or broken wire strand. If none is found, wipe down the inner cable with some paint thinner on a rag & then re-lube with a thin coat of wheel bearing grease & re-install it back into the outer cable.

Re-attach the cable to the speedometer, and if possible, spin the end that would go to the front axle with a cordless drill to test the speedometer, this way you can see if it's the instrument or the cable(maybe the front axle gearbox)that's the problem.

It may also be that the needle is bent and is getting stuck on the dial at the 45 mph mark. When you have it open checking other things, gently push the needle around and make sure that it moves freely.

Figured it out... I didn't have the notches in the gear housing lined up with the hub on the wheel. :blink: so it wouldn't give an accurate reading.

quick side note: i tried to check if the speedo was working right by hooking up a drill to the end of the cable, as suggested by Mfolks, but didn't realize it needed to rotate in the counterclockwise direction. Once i figured that out, my drill would only get the speedo up to about 20 mph. but i needed to check at over 45 mph. So i ended up attaching a square bit into my pneumatic impact wrench to get it up to speed :woohoo: it was interesting... but it worked like a charm. that way i was sure that the problem was in the gear housing and not the gauge itself.

But its all sorted out now, and just got the inspection finished up this morning, and promptly took the long, twisty way to work (about 3 hours late)

So now its all legal for the first time in 3 years and i absolutely love it... thanks to all who have taken the time to educate me and all that have posted about their experiences. i have learned so much from so many people whom i have never even met.

Thanks!

Happy our idea's gave you places to look! Enjoy your bike, but watch out out for distracted drivers(texting, cell phone users, mom's with a car full of kids fighting, and plain idiots on the road).