Maxim Speedo Mod - 140 mph!

[MAXIMAN]

For a couple years now I've looked on my brother XSive's 11's with lust in my heart for a "real" airspeed indicator. I mean "thank you US Government" but no thanks for your damned speed limit crap and the resulting 85 mph speedometer.

My good buddy Dan Hodges bought his '81 SH brand spanking new off the showroom floor. Within a matter of weeks he had swapped that worthless excuse of a psuedo-speedo for a brand new '79 SF 160 airspeed indicator.

My dilemna: I love the digital information I get from the LCD display of the Maxim's pilot box. The digital fuel gauge is the bomb! The warning lights are nice too. So I had to device a way to keep the OEM look and function of the mighty Maxim's LCD pilot box and still have a real speedometer.



I'll post the procedure of how to do this later. I'm sure many of you have already dechipered exactly what I did.

[MAXIMAN]

I got to looking at the other XS instruments. It's obvious they were all about the same size. I looked at the parts diagrams online and it appeared a speedo from any of the XS series (650, 750, 850 or 1100) would actually fit in the Maxim pilot box. But I wasn't willing to spend a lot to test the idea. Maxim pilot boxes generally are not cheap...and neither are the 160 mph speedo from the rare '79 SF.

I got lucky. I was watching a Maxim cluster on ebay and nobody was bidding. It worked and was in very good shape. I got it for about $50. A few weeks later I snagged a 140 mph cluster from a '77 XS750. I hadn't had any luck even finding a '79 SF indicator and when I did see one it usually fetched $150+.

Since the speedometer drive on the 750 is the same part number as the Maxim and XS11 I knew the actual indicator must be compatible. I paid about $30 for the 750 speedo on a hunch it would be "swap-able"

Here's the XS750 cluster after I removed the bezel.



Now after I removed the glass face. The speedo on these XS are sealed in a plastic case with the metal ring...gasket and glass face.

[MAXIMAN]

In order to get the actual instrument out ...intact...I had to split the case like so...



Here you can see the two indicators are identical in shape and size except the Maxim employs a push button trip odometer reset. Not a problem as you'll see later.



This pic shows the removed OEM indicator from the Maxim pilot box.



I had to slot the case and the black cover of the Pilot box to allow the thumb roll trip odometer to protrude through the side. I used a dremel to exact the cut.



When I finished I filled the exposed slot with black RTV silicone and smooth it out. You can barely see it. It almost looks like it came from the factory that way. And of course the finished product. A XJ1100 LCD pilot box complete with a 140 mph speedometer!





Not if it will just work. I have yet to test it. When Zilla gets out of surgery I will install it and report back here.

[MAXIMAN]

Oh yes...while I was at it I reset the odometer to zero. Since I'll be running on a "new engine". It will make it easier for me to keep up with how many miles I have on the rebuild. Besides I'll always have the original pilot box for reference.

[GNEPIG]

.. Very cool! it looks very stock and you dont need to go faster than 140 anyway, its about how fast you can get to 140 that counts.
..its people like this guy that makes this site so groovy

[Ken Talbot]

Nice job there, Maximan!

[MAXIMAN]

Thanks for the kind words fellas.

not only do I not need to be going faster than 140...I'm not sure that full dressed behemoth would pull it off....even if the motor winds up cranking 100+ hp. I mean how fast can ya push a 4x8 sheet of plywood through the air? (read Vetter fairing)...

[MAXIMAN]

I was poking around and found some reference to a guy named Dean Koehler. Apparently he had done a mod on his XJ box with a '79 SF (160 mph) faceplate. Then sent his original XJ speedo in to have it recalibrated to the face plate.

I never could find the actual thread though. I guess it was too old and been lost somewhere in cyberspace.

I suppose he did this to keep the "push button" feature of the tripometer. Jerry reported that an XS speedo will not fit in the XJ pilot box.

That is true...unmodified...an XS speedo will not fit because of the XJ pilot box due to the tripometer knob. But as you can see in my mod if one simply slots the pilot box and cover such that the two pieces "clam shell" around the tripometer stem then the XS speedometer fits perfectly.

The disadvantage to my method is you lose the "push button" tripometer. However the advantage is you don't have to send the unit in for calibration.

Thanks

Cg

PS: Any XS speedometer should be readily adaptable to the XJ box utilizing this modification

[dorkpunch]

so am i the only one with a speedo that goes to 240?

[trbig]

so am i the only one with a speedo that goes to 240?

Well... if that is in MPH... then yes! lol.

Tod

[Dan Hodges]

Originally posted by MAXIMAN
I was poking around and found some reference to a guy named Dean Koehler. Apparently he had done a mod on his XJ box with a '79 SF (160 mph) faceplate. Then sent his original XJ speedo in to have it recalibrated to the face plate.

I never could find the actual thread though. I guess it was too old and been lost somewhere in cyberspace.

I suppose he did this to keep the "push button" feature of the tripometer. Jerry reported that an XS speedo will not fit in the XJ pilot box.

That is true...unmodified...an XS speedo will not fit because of the XJ pilot box due to the tripometer knob. But as you can see in my mod if one simply slots the pilot box and cover such that the two pieces "clam shell" around the tripometer stem then the XS speedometer fits perfectly.

The disadvantage to my method is you lose the "push button" tripometer. However the advantage is you don't have to send the unit in for calibration.

Thanks

Cg

PS: Any XS speedometer should be readily adaptable to the XJ box utilizing this modification

This is really slick,with modifications like this we will have to start calling you Max, as you always seem to take it to the Max.You and Zilla are slowly encroaching on Attila's claim to the most tricked out stock looking Eleven.Where are my FJ carburetor's,they gotta be around here someplace.This is getting crazy!

[MAXIMAN]

Well it's not as perfect as I'd like. As soon as I can land a '79 SF indicator (160 mph) it's going in.

No no I don't need the speed. But the motif of the XS speedo faceplate matches the XJ tach. If you look very closely the 140 XS indicator I installed is a different shade of black than the OEM tach. And the needles don't match. Little stuff like that bugs me.

Would you like to donate Atilla's air speed indicator to the cause? hehehehehehehe...

[John]

You need a 160 Speedo?

Do you really think it'll go that fast? If you do, then I have a 160 speedo available. Make me a decent offer.

[MAXIMAN]

You didn't read the post. I said it would NOT go that fast. But it would look nicer. The SF indicator has the same style lettering and and same needle and the same color background on the faceplate.

I'll pm ya.

[Dan Hodges]

Originally posted by MAXIMAN
Well it's not as perfect as I'd like. As soon as I can land a '79 SF indicator (160 mph) it's going in.

No no I don't need the speed. But the motif of the XS speedo faceplate matches the XJ tach. If you look very closely the 140 XS indicator I installed is a different shade of black than the OEM tach. And the needles don't match. Little stuff like that bugs me.

Would you like to donate Atilla's air speed indicator to the cause? hehehehehehehe...

The color and logo is different but I doubt anyone but us would notice.Atilla's air speed indicator is quite macho, but short of being kicked out of the back of a C-130 it read's faster than it will ever go.My 85 mph Jimmy Carter special indicator is still in the box the 160 mph Reagan special came in,so I can always reinstall it if Hillary comes to power.