Maxim Speedo Mod - 140 mph!

[Dan Hodges]

XJ air speed indicator Maxed

Zilla truly stand's alone as the trickest XJ yet.This is the only XJ I have ever seen with that speedometer and it look's like it came that way from Yokohama,totally cool.

[Geezer]

Originally posted by MAXIMAN
Yeah I know that. The speedometer working is not my concern...but the other functions of the Pilot Box (tach...warning light...fuel gauge...etc).

Thanks
Cg

You sure did a nice job on it and I hope the electronics in the rest of the panel work for you.

I posted the note on the ratios as an FYI because there was some question about it working correctly for your bike. It's too bad tach ratios were never standardized...

Geezer

[OpFlash]

you went back in there and re did it wow nice work it does look alot better with the needles the same color etc.

[Tresjay]

I just bought an '79 SF and the speedo "lags" reality by more than a minute. It's movement is smooth and appears normal in all other aspects. By "lags", I mean I can run it up to 5000 rpm in 5th gear and hold the throttle there, and the speedo will show 30 mph. After 10 seconds it might creep up to 40 mph. Only after 90 seconds will it show ~75 mph.

I took the instrument out of the bezel, and found that it really isn't serviceable (as noted in the photo above.) For people that have actually destroyed the plastic and seen inside, do my symptoms make sense?

I assume there's a magnet mounted on the cable and spins in close proximity to a magnet mounted on the needle that is counter balanced by a spring. I considered trying to oil the pivot of the needle by inserting a syringe through the cable entrance, but I don't want to risk spattering the inside of the lens or the legend.

Has anyone managed to open the plastic in such a way as to be able to reassemble it?

I'm open to any suggestions, including my own willingness to live with the problem.

Tresjay

[Tresjay]

Oy. SF.

Note to self: Always "Preview Reply".

[TopCatGr58]

Easy enough to fix!!

As for the gauges, I found out how to pry off the metal bezel from the casing, see this tech tip on repairing an aged instrument plate and broken needle!
T.C.

[Tresjay]

T.C,

My speedo is like this. Mine is all plastic, not a metal can like your tach. Thank you for the tech tip, but I'm not sure how relevant it is to my problem. Maybe I'm missing something.

Tresjay

[John]

Your problem may be with the speedo 'drive clutch' located in the hub on the left side of the front wheel. If the tangs of the clutch don't properly engage the speedo drive, that may be the reason for the lag time. The tangs may not be making good contact with the drive, and slipping when you first start off, and then after a while the friction between them will be enough to get the drive up to speed. Kinda like a slipping clutch in the trans.

[Tresjay]

I didn't realize there was a clutch in the hub! After looking at the parts diagram, what you say makes sense. I'll let you know how it turns out. Thank you pointing that out.

Tresjay

[MAXIMAN]

UPDATE

I've put about 120 miles on the bike since the rebuild. Zilla has not rejected the 160 mph transplant. As a matter of fact the speedometer it more accurate now than any XS I've ever had.

At 4000 rpm it indicates 63 mph.

At 4200 it's indicating 65

At 5000 ...79 mph and at 7500 in top gear it rings up 120 mph.

If you calculate the speed using a final ratio of 4.76 and my Venom 130/90 16 OD of 25.2 ...calculated speed is almost perfectly correlative.

[MAXIMAN]

140 mph indicator up for grabz

Ok...any of you XJ owners want a 140 mph speedo? You can have the one I got. You just have to replace your old Jimmy Carter special (85 mph version) with the XS650 Speedo. All you need is an hour, a screw driver, and a dremel.

Just lemme know. First come first serve.

[HobbyMan]

Cool mod. I bought a 79 standard XS spedo from John and dissasebled it to match the mileage of my 80G. After doing that I remanufactured a damper out of bicycle inner tube and its waiting to be installed. This forum helped out a lot. BTW: I had the same problem as Tresjay, just not so bad. I lubed the cable and the oil solved the problem.

[Deano K]

Deano K. here - haven't posted in years since I've moved on to FJR land but my son Kirk has my XJ and the 160MPH mod is still working like a champ. You do retain the pushbutton reset for the trip meter in fact all is retained except for the face which is swapped. The accuracy is suspect on the low end (<25mph) which indicates more than actual speed. I also had to enlarge the window in the XS face for the trip odometer to accept the XJ.
Hope everyone's doing well and keeping the blue side up!
Deano K.
Dean Koehler
'04 FJR1300a

[randy]

Hey, Cody.

Coudn't help noticing that you zero'd out the odometer. How about a tech tip on that?

[MAXIMAN]

Yep...
The replacement was inaccurate to my bike anyway. When I installed '79 speedo it was the same time I rebuilt the engine so it would be easier to keep up with the mileage post rebuild I zero it.

I just took a pencil eraser and pushed each number ring around to zero. The gears are plastic and flexible. It sounded like a rachet as I turned them but apparently did not hurt them as they work fine.