is this a broken tachometer cable?? how replace and fix?

[stephen2us]

Hi.. I have a 1981 special II, and after switching the handlebars to euro styles, I noticed my rpms were reading zero when throttling. investigating I found what is in the picture, and I assume this is a tachometer cable? I am not mechanical, and changing the handlebars were challenging enough, but would like to fix this if possible? can you still get a cable? and how do I do this with details? Thanks! I assume the other end is somewhere in that hole still... thanks for the help... newbie here...

 

[bcware]

Remove the phillips head screw below the motor mount in that photo and the metal bit will pull out. A new cable just pops right in. The screw keeps it from coming out. The end on the tacho just screws in; get some slip joint pliers to ease removal and installation.

Oh, and yes, it is the tacho cable. Make sure to lube the new one before you install it.

 

[stephen2us]

THANK YOU!!! Going to give it a shot when my new cable arrives!!

 

[stephen2us]

Well, this isn't going well at all.... The old piece that was stuck in the hole, was pretty much welded on, and had to drill it out... Took a lot of work, and scary since I wasn't familiar with what was actually in the hole, or suppose to be there....

The end result thus far, is I have a small drill bit that broke off into the smaller hole (see pic) somehow.... It's not sticking out, so I can't get pliers on it. There is probably between half an inch to an inch of bit in there...I believe I just have to get that piece out, and new cable will be ready to put on... But no clue how to do so without messing things up even more.....

Steve

 

[BBS360]

Someone else might have a more specific suggestions but my first idea is to stop drilling immediately!

It's hard to tell from the picture but it looks like you've gone beyond drilling out the tach cable plug and have started drilling into the tach worm gear assembly inside the valve cover.

I'd take the valve cover off and remove the tach worm gear from inside. Hopefully it's not too damaged and the drill bit can be removed with the worm gear removed.
I have not personally taken mine apart but there's a circlip holding the assembly together.
http://www.yamahaparts1st.com/oemparts/a/yam/5004207bf8700209bc786eb4/tachometer-gear

 

[lemonhead]

Yikes. Hopefully none of those metal shavings make their way further down into the engine...

 

[arfstrom]

That rubber seal, has been their for 30 years. It is going to be a PIA. to get it out. I could not tell if the drilling has accidentally into the head. I think it is going to be easier to pull the head off and then you can apply a mini crow bar, (big screw slotted driver) and push it out from the other side.

PIA = Pain in A@@
Good luck

 

[stephen2us]

yeah that bit isn't even remotely coming out from the front, so I'll have to remove the valve cover--so is getting to the tachometer gear, just a matter of removing the gas tank and then the bolts for the top of the valve cover? any and all details would be GREAT.... I'm in this mess because of myself, and was drilling into something I thought was part of the leftover cable... SIGH....

Thanks

 

[arfstrom]

Have you downloaded the manual yet? There is two of them out there. On the Garage main page, one of the top two links in the threads is manuals. download this one two.

http://www.xs400.com/forum/showthread.php?t=14495

its 45 megs.

You will need the torque settings for each nut, bolt and what ever else you remove.

 

[bcware]

Some things to ponder:

If there is damage to the valve cover it will need to be replaced, but the head and valve cover are machine matched. If you replace your valve cover and not the head you will likely get some leaks. Use of a sealant might stop this, but I have no idea.

If the motor is in the frame you'll need some kind of mini torque wrench to fit between the backbone and the head; I was not able to fit anything normal in size in there for all of the bolts. I tightened mine by feel and not a torque setting (with a box wrench), but this can be challenging if one does not have the experience. If you're a beginner you'll almost certainly over tighten everything; keep that in mind.

I would plan to replace the valve cover and the oil seal around the cam. You'll need sealant as well; something non-hardening. There isn't much to it; just 14 bolts I believe. There is a specific order of removal and tightening to avoid warpage. See the manual that was linked above.

 

[Winnipeg_79_XS400]

Looking to remover my tachometer cable. I plan on removing the head cover, remove the gears and cable and reassemble. what plug I use is yet TBD. i

If I do this, will I have to make any adjustments to the head assembly, or possibly the ignition/timing?

cheers

 

[xschris]

These is no real benefit to taking it out. It will save you an once or so in weight but that's it. I took mine out on one of my bikes and epoxied the hole afterwards. After a few years decided I liked having a tach for tuning and see where the engine was running at so I put it back in.

 

[Winnipeg_79_XS400]

I' going to a single gage. Like you I don' want it to be permanent.

Any required adjustments or returning after a head cover removal?

 

[xschris]

Re-seal rocker box, new cam seal, set valves and re-time the bike. Set points if you still have them. Also keep in mind that setting timing accurate with a gun will be hard to do if you don't know what rpm's the motor is at while it's running. 1200 is where it needs to be. You could be off quite a bit without one. I would just let it be or cut off the end of an old cable and make a plug out of it. It's your bike do what you think is right but unless it's going to be a race bike and every bit of weight counts it wont do anything to improve the bike.