82' xj750 maxim repairs.

Did you ever for sure identify the gauges as to which bike they came from? I thought I read earlier that the new gauges had a mechanical tach and your original was electric?

 

I'm almost positive they came from a 79 xs1100 not an 81 like the marker said but I'm not sure 100%. Oe tach was electric and so is this one. Lots of cool gauges at the yard but 80% of them had mech tachs so I avoided them.

 

After a little test ride. The Speedo is a bit slow ( but catches up ) and the tach bounces.. gonna do some research into what would be making it possiby do that and also chase the signal wire all the way to the coil and tci unit. It's strange because the old tach worked fine, never a hickup, so it'd be odd that something happened at that same time to the wire somewhere.

Would the two different tachs take a different signal or something since the 79 Yamaha might not have had a tci unit?

 

The bouncy speedo and misbehaving tach speak to them both needing to be cleaned and lubricated. The tach might have cold solder joints on the circuit board, so look at those too,

 

Good call. I'll pull them both off and open them up. I had the back of the tach off and it all seemed good when I was chasing what wires were what, but I'll take a closer look for sure.

There's two little nuts I didn't undo, so I can obviously dive a bit deeper into it

 

I can't seem to get in enough to get the circuit board out. The front glass and round housing are over the lip n won't even spin, the two nuts on the back just loosen the gauge / circuit board in the case.. with the sun coming in through the window I could almost get goodenough of a photo. The brown wire solder looks a bit worse than the grey wire but I'm also not sure what a cold solder is.



I'll keep trying to find a way into this tach.

 

A cold solder joint will be dull and often a little wrinkly. The brown wire in your top pic looks kile t might be a clod joint. When you get in there all you need to do is hit it with an iron to reflow the solder.

It seems to me that the gauge comes apart like this (maybe): Repairing your 700 gauges

 

They seem to match Ebay XS1100 Special. The XS1100 and I believe the XJ1100 get the tach signal form the AC Generator that is mounted directly to the crankshaft, most of the other XJ's get the signal from the TCI. However, I am not sure if it would make a difference. I can't recall anyone ever making this particular swap. +1 on above where bouncy gauges usually do indicate a need for lubrication - sometimes on the speedometer you can just lube the input shaft bearing from the outside and that will work.

 

On one of my older model bikes I had to bend the front cover off of the rim to remove and get to the internals. Here is a link for what I ended up doing, but I am not sure yours are like this.

 

I do believe this is what I have to do.

Ok thanks for the info that puts me in a direction atleast. The Speedo is just a tad slow on the response ( a few seconds ) , does not bounce at all. Will try lubricating the Speedo. The tach bounces but also doesn't read even close to right so I'm assuming it's signal/voltage related

 

Also here's a couple shots of them mounted. Really like the look n can't wait to have them working properly (fingers crossed)!

 

I like the look of that! I am still fighting with my XS1100 but that is another thread. Love the bars and how you have shortened this bike up. I guess if I do that all new cables...it would be worth it.

 

Thanks man! I'm pretty happy with how it's turned out so far. If I can just get these last few things sorted for the rest of summer I'll be stoked. Can't afford to throw any more money at it until winter time haha

 

After chasing the grey signal wire all the way back and it looking good ( i figured maybe i bumped it when i was putting thank on and off or something ), i wired in the old tach and it worked, so now im going to stop poking around my bike and start pointing to the tach. In response to some photos, its been pointed out that the brown wire in the tach (12v power) might have a cold solder inside of it, the white signal wire seems to have a very good one on it. Now my question is are those two wires married at all, would the brown wires connection interfere with the incoming pulses from the signal wire ? If so then that could be the culprit.

Im also going to call the salvage shop tomorrow and ask him if he tests all these parts prior, If not i think i saw a couple more laying around and maybe hell let me switch them and i can see if another one works.

worst case find one on ebay maybe and try my luck there with a swap.

anyway making progress, and cancelling posibilities out which seems like a good thing!

 

https://xjbikes.com/forums/threads/xs1100-tach-swap.8405/

i came across this link just now while doing research and it seems im not the only one. So maybe it wont work without some wizardry. Not sure what the guy meant by calibrating it though?

( he also had just plugged in the connectors since he had no movement at all )
They do fit together but signal and power wire are reversed.


Also ive read a few times online about inline resistors to get tachs back to where the belong, has anyone had any experience with that sorta thing. I guess thats just for when a tach is bouncy but reading pretty accurately.

 

Does anyone know what year Yamaha went from alternator signal to coil or does it vary by bike. Hoping to get back to salvage yard and maybe find another gauge that'll slip into this housing.

 

I think you are on the right track here, and I believe (others may know more) but the early 80's XJ650, XJ750, and XJ700's I believe all used the TCI signal to derive the tach signal . The XJ1100 and the XS1100 I believe both derive the tach signal from the AC Generator. I am clueless on the other XS series, but it may be any bike with the mid mounted AC Generator and subsequent reduction gearing that utilized the TCI signal.

The answer in that thread is a bit too simplistic and probably why the thread died unanswered. I looked at a XJ1100 tachometer and the difference in input frequency is quite dramatic, and it looks like the AC Generator utilizes a 12 pole winding. The result of that is the difference in tach signal frequency is six times higher for the alternator output signal compared to the TCI output signal, which would make the tach read off by a factor of six. I won't say it is not possible to re-scale the XS1100 tach, but it would be quite a science project to get it right.

Edit: removed 550 mechanical drive tach

 

Thanks for the info! An xj cluster / tach is definitely the route im going to go now. The more research i continue to do, im finding out the difference between the two is quite drastic as you have pointed out. I have the abilities to follow someones instructions and POSSIBLY figure out how to re wire the tach but i think for the time and money it would cost i should go a different route, and eat the 100 bucks i spent on the cluster and go with a different set up. Like i said id love to find a tach thatll fit the housing , not sure how consistent yamaha was with their gauge sizes but ill bring the tach and compare at the yards. I wont have time to hit up the two salvage yards we have here for another couple weeks but maybe ill be able to find one thatll fit the housing or just put a whole new one in now that the wiring is already all done. If anyones looking for an useless set of XS gauges for the xj let me know haha.

 

I've noticed the xj550 seca round gauges are similiar. Maybe the tach would match up dimension wise.

 

If I can't find any locally ill be buying some online. Does anyone have a 550 with round gauges that could toss me some dimensions of the tach? Would be a huge help!

Tia!

 

Or a tach for sale would be even better !

 

mechanical drive tach on the 550

 

Gahd dammit. Ok thanks. I saw a thread somewhere that the gauges look identical but some went to tci signal in like 82-83 or something but at this point I've read so much it's all blending together haha

 

The only tach ive found that seems similiar in size is an autometer one but it's for cars so no neutral light. I guess I could wire up one of the two indicators in the middle that I'm not using to be a neutral light, I do like the little green light in the gauge though.. Other colors are white and red.. not a huge fan haha

 

Im also shopping around for carb sync gauges and a colortune plug, does anyone recommend any manufacturers without breaking the bank? i understand a good tool is worth money, and i invest in them though. Lots of gauge sets online to purchase and not too familiar with them to know what one should cost for accuracy.

Do the gauges cut out the need to colortune or should both be done to ensure accuracy?

 

The colortune lets you see the fuel mixture as you adjust it. You can read the plugs instead, but that takes a lot more time and requires more practice to do correctly.

The vacuum gauges measure how much vacuum the pistons are pulling. They are seperate measurements, and you need both. You can get by with a homemade manometer, but check e-bay for a used set of stick gauges. IMO dial gauges have become plentiful and cheap, emphasis on cheap, so skip those for now.

 

Check out Acewell!
I installed one and they also have an adapter to convert your analog speed sensor to digital without using those magnets.
I put it on my bike and it's very clean looking!
I also switched out the Maxim tank for a Seca tank and Used the Acewell gauge to add the fuel sensor. Acewell has many variations to fit all kinds of bikes!
I spent a long time researching this, so far I have everything working but haven't finished up the speed and RPM yet as my bike hasn't ran since tearing it apart and rebuilding so those are next up on the list in the near future.
You can check them out on my profile
This can help you get to the correct website quickly:
http://www.acewell-meter.co.uk/Acewell Speedometers/ACE-MD52/index.htm

I think this was the Speed Sensor Adapter:
http://www.acewell-meter.co.uk/Acewell Accessories and Sensors/Speed Sensors - Cable Drive/ACE-S1.htm?action=full&id=264

 

Thanks for the info, for now im still hoping to find a gauge thatll fit in the housing or just a new cluster all together. Not sure if id go the electronic route but good to know i have the option. I currently dont have a fuel gauge as the wires have been cut from the fuel sensor but im hoping itll work when i get around to it.

 

I also hope to find a seca tank for mine so i might also not even bother getting that to work until then. with the riding i do i just fill up every few rides, on long runs i just count my trip odometer. Not the first vehicle.. or the last ill have to do this with probably haha

 

If you have the wires, it'll work. It's powered by the gauge using the ohm resistance to show how much fuel is inside.

I've seen a post around here about tank compatibility per year and models, with that info I found someone on here selling their Seca tank. I then stripped and repainted it.

 

Nice. Yea that's definitely the plan . Started catching up on your thread , good work man!

 

So ive been enjoying the bike but the rainy winter is setting in and with the cost of insurance and my wanting of wrenching i have benched her for the winter to get some much needed things done. I figured id start with the carbs since i know my last go around of "cleaning" them didnt include throttle shaft seals, fuel rail interconnnect seals, mixture screws ( and springs ) ect.. I spent a few days reading the chruch of clean and figured id get started the other day. I cleaned off a nice perfectly flat workspace ( my glass drafting table ) and got to work, taking lots of photos, i know the church of clean recommends 100 and i think im going to have just a little more by the time these are done being dissaembled. Ive gotten as far as to breaking the rack, i stopped to do more reading on the next sections rather than continuing like my brain is telling me too. Now is where things seem to get very precise and important compared to the first steps. with all the throttle blades, screws, seals and spring placements.

My rebuild kit came with 6 new o rings for the fuel rail interconnect tubes but they dont fit perfectly so im going to order some from chacal. Well see what else doesnt seem perfect and all that will be ordered as well.



















The new o rings provided.. maybe they are for something else but there is 6 of them so i dont see what else theyd be for.. i definitely dont like the look of that seal so like i said i will be ordering some other ones.




A question i have going into the next section is

- Ive read about filing the back of the throttle shaft screws, mine seem to have a bevel to them already and i can tell these have been broken before by how easily the rack screws came out ( other threads say they should be very difficult to remove ). The throttle shaft screws seem to be almost flush with the shaft already.. id hate to have the file hit the shaft at all with how little protrusion there is currently but will do whats necessary.

Here are some photos even though they might be hard to see.





I am going to be going alot slower than i want to with the disassembly of the rest, its intimidating, not from a skill level but from the amount of importance stressed in the threads about doing this right. Maybe ill even hit 200 photos by the time im done.

Thats all for now, Im going to keep reading and reading and reading and maybe get a bit further today. Good thing about it having the plates taken off of it is there is NO rush to get this done, i got months and months to tackle my list of objectives.

I keep reading about doing it right or not doing it and im gonna do my best to tackle this properly for the second time and avoid the 3rd and 4th haha

 

another question is what grit is appropriate for polishing the slide bore in the carb body and the slides themselves ( i have some varnishing on the bottom of them )

 

do not polish slides with any sandpaper, it will ruin them. clean with cleaner and soft rag.


only Mikuni carbs need the screw filed down the screws are peened

 

I got the throttle blades out. Marking each ones orientation . I marked them with an arrow pointing down towards the bowl. After taking about 50 photos I started to take out the shafts along with the accompanying springs and seals. Laying them above the carbs in the exact orientation they came out. The shaft seals seem good as to not be originals but who knows. Some have some small cracks on the inside flange type part of the seal so I'm just going to replace them all anyway. I've come this far, to not replace a questionable part would be ridiculous naive. Behind where the throttle blades attach to the shaft is some tarnishing. Will clean up with cleaner and a soft cloth as to not score anything. Is this a sign of anything I should prbe besidesconcearned about beside prolonged exposure to fuel?

 

Also the 6 plastic washers That accompany the outside of the throttle shafts.. should those be replaced with new ones while I'm here even though they appear fine, as I'm assuming they act as a dust guard for the throttle shaft seal.

 

Nice share, great pics...even in focus! Even with the correct "O" rings you will have to make sure the carbs side of those fuel tubs are supper clean. I have had some so bad that I have had to polish them with my dremel and a polishing head. Using a little oil like MMO on the rings and carb parts might help too. Great job on the tear down and sharing the pics and how you are doing with the project. Keep up the great work!

 

Thanks! ill probably be worried until the motor is tuned to the carbs afterwards, the valve shims have been checked/replaced and i hear it run properly. Trying to use that as a good thing though!

Yea i took some photos of the inside portion of the carb where the tubes go in.. not clean.. neither are the insides of the tubes. Going to find a tool to clean both good!

what do you mean by MMO? and thanks for the tip!

 

should be more than 6 spacers 7 needed. do not always needed to be replaced

 

You're right. I actually have 8... One on either side of the throttle shaft bracket or on the ends the circlip goes onto ( carb 1 and 4 ). Okay they all seem straight and without damage.

 

i sprayed the throttle blades with some cleaner and tried to get as much of the tarnish off that i could. whats left isnt able to be felt with a finger so im assuming it should be okay, i may soak them if needed. I havent taken out the enrichment circuit plungers and springs yet, they all slide smooth and have the same tension to them, should i just take them out while im here? i know the answer is probably yes but why not ask haha?

I then just cleaned the carb bodys and the fuel interconnect passages. ive inquired about a quote to get the throttle shaft seals and fuel rail o rings as well.

 

"On the HSC32, carbs #1, #2, and #4 use 2 shims per carb, and the #3 carb uses only 1 shim. Thus, on HSC32 model carbs, there are a total of 7 shims used per entire carb rack."
xj4ever catalog

 

I havent taken out the enrichment circuit plungers and springs yet, they all slide smooth and have the same tension to them, should i just take them out while im here? i know the answer is probably yes but why not ask haha?

you need to remove them to inspect springs for rust and that the seats for them are clean

 

And yea you're right, again haha. Was confusing the locking washer on number 3 as one. Too much carb cleaner fumes today I think.. classic. Good thing I stopped for the day.

 

Enrichment circuit is taken out now. Besides some crud on the parts that see the day light , they seem to be in good shape. The seats inside the carb body seem good too, theyll get a quick cleaning anyway of course, but im pleased to see i dont need more parts to order !

Im pretty much on hold now until i make the order of parts and they arrive for re install. I want to start some other tasks but im trying to complete only one thing at a time so it all stays fresh, and the improvements i make on the bike this winter dont get lost in a bunch of half done mini projects, been there before...

So far i have new throttle shaft seals, hex head button screws (to replace the phillips heads in the throttle shaft/ butterfly ), Fuel supply o rings, and idle mixture screw orings on the list and i think thats all i need.

 

Im not sure why all my photos from dropbox seem to go sideways on this site... not this one atleast.

 

Even though i dont see much grime on them should i still soak them in parts cleaner? or am i fine just cleaning them by hand like i am, and then blowing them out with a compressor?

 

Also got the mixture screws out. Carb 3-4 has some cruddy screws, springs, and washers. Good thing the rebuild kit came with 4 new mixture screws and hardware.

 

Does the spring act like a lock in ensuring this mixture screw doesn't back off , or what purpose does it have?