I think my speedo might be screwed...

[Incubus]

So I took Incubus for his first real ride today. It wasn't real long, just a country block (5-6 miles) and I was pleased with his performance. Good idle and kickass acceleration. The handling seems a bit off, but for the last couple of years I've been riding a Shadow VT1100, which is much lower and a bit longer, so I think it may be just the wheelbase and higher center of gravity that feels different, not wrong.

I do have one issue. I'm riding Incubus without a windshield right now, which I am no longer used to. On one long straightaway, WOT, third gear 6,500 rpm on the tach, the wind and torque trying to tear me from the bike, flash past a pickup seemingly doing the 55 mph limit.... speedo says 30 mph.

I'm thinking that might be a little low. Thoughts?

Patrick

[Ivan]

Well, on my 79 with the original FD, it redlines at about 85 in third gear, so yeah, I think your speedo is not keeping up.

Maybe you are just hammering it so hard, it can't swing that fast.

[DiverRay]

I would pull the cable and spray a silicone or light oil lube into the back of the speedo. I do NOT use WD40, as I don't think it will hold up under "adverse conditions" like the silicone lube does.
If you ride the machine for a while after the lube, you should notice the speedo getting "closer" to a real reading. It MAY do that without the lube, but new oil can't hurt!

[Ivan]

Also, if you notice that the needle swings back and forth a lot, pull the cable and pull the core out. Get some of that LubriPlate grease. The cheap stuff that is somewhere between snot and lard. Smear it all over the first half of the core and shove it back in.

Another suggestion going along with Diver Ray, is to buy a cheap medicine dropper that has a large diameter, and pull the bulb off. Put speedo head lube in it and gently squeeze, to keep from spraying in the speedo and getting stuff all over the glass.

[fredintoon]

They all do it

- - - I do have one issue. I'm riding Incubus without a windshield right now, which I am no longer used to. On one long straightaway, WOT, third gear 6,500 rpm on the tach, the wind and torque trying to tear me from the bike, flash past a pickup seemingly doing the 55 mph limit.... speedo says 30 mph.
I'm thinking that might be a little low. Thoughts?
Patrick

Hi Patrick,
5 out of 5 Yamaha round speedos on our various XS bikes ALL read slow to some extent
or another and on the ones that haven't died it seems to be getting worse with age.
Try all those tricks that others have posted and in addition, do a mileage check.
Our working speedos all show they've gone 10km between those 10km hiway markers.
(except the US sourced mph unit which reads 6.2 miles)