Tether Killswitch

[89fj1200]

Hey everyone.  Im looking to install  tether killswitch on my bike so that I can take it to tracks.  I was wondering what wires I need to run it too and Also do I need a normally open switch or normally closed?  Thanks for any help!

[andyb]

Two ways to do it. 

The fast dirty (and wrong, and ghetto) way to do it is to drill a small eyescrew into the killswitch button itself.  Many tracks will accept that.

The right way of doing it is buying something like this, which is what I use, or that which will work also.  Both include directions and such.  Pop open the switch assembly and you'll see how it works, just follow the colors of the wires and splice it in appropriately. 


However, most dragstrips aren't anal about them if you've got a relatively stock appearing bike.  The track I usually run at will allow you to skip it if you're not running a dedicated dragbike, but some get snotty about it.  I've seen a lowered but otherwise stock appearing GSXR1000 run 9.19's without one without an issue, for example.  Go to the track and watch sometime, and ask around what the tech is like.  Usually they're more concerned with having the right gear on and a helmet that meets requirements.

[89fj1200]

I already have the killswitch, I just need to wire it up now. My local powersports store was about to tell me which one I needed,  I just need to hook the 2 wires up now.  I cant wait.  My 83 vf750f runs 12.3s consistently.  Im hoping to see close to 10s on the 1200.   Ill post up timeslips when I go to the track next.  It should be either this weekend or next.

[andyb]

10's are doable with a strap easily enough

gluck!

[fj1289]

What type of setup are you using on the vf750f?

Figure out which wire come from the kill switch and splice into it.  The tether then functions just like the kill switch.  Use a voltmeter to back probe the connector from the handlebar switch to see which one has no power when the kill swith is in the off (or stop) position, and has power when the switch is on (or run).  It is probably a red and white wire according to the wiring diagram.  I've changed out switchgear, so I can't use mine as an example.

Like Andy said, strapping the front helps a lot.  The soft springs in the FJ fork let it droop quite a bit static, then on the launch the forks get that distance to some upward momentum whtat makes it want to wheelie more.  The strap keeps it low and tight and prevents that "slide hammer" effect.  The 89 is easy to lower at the rear too - I made a set of dogbones with two sets of holes - one set of holes shorter to raise the rear for street riding, and a set of holes longer than stock to lower the rear for the dragstrip.  Here's how it set lowered in the rear and strapped in the front.  This was just a bit more than 2 inches of clearance under the exhaust.  



Has second gear been undercut?  If not, make VERY DELIBERATE shifts into second.  An airshifter is even more valuable for that insurance than it is for cutting time.  

Let us know how you do!  

Chris

[89fj1200]

No I dont believe its been undercut.

[andyb]

Meh, it'll be fine.  My 90 was never undercut and has over 150 passes on it.  Trans is fine (well, was when i tore it down for other reasons).  Actually if any gear gave me issues, it was 4th, and that was exceptionally rare.

[89fj1200]

Okay so i never tracked the bike yet, I just ran the vf750 again.  Now i want to run the fj, How do you guys that race strap the front? It already has progressive fork springs.  Also I wanna get sprockets, does anyone have any suggestions?

[andyb]

17/40 to 17/42 is probably in the ballpark for gearing, depending on how much you've got done to the bike, your weight, and the air quality.

Strap the bike just like any other, though it's easier to use the lower caliper bolts for it.  One hand on the brake, one hand on the strap, grab the brake, pull the strap, and then use a cable tie to keep the strap's free end from flying loose.  Springs won't make a whit of difference.

If you are going to give it a decent go, you can also make yourself a set of slightly longer dogbones and lower the rear some.  Between an inch and 2.5" works really well, but it makes using the kickstand impossible without someone to release the strap for you.