Gremlins...

[trbig]

OK... got my bike FINALLY put back together today. For a re-cap... XS motor, XJ head (Bigger valves) with XS cams, new cam chain. When I started taking the bike apart, and since I have had it, I have been reading on here of how fast these bikes were. Mine felt like a lead turd. At highway speeds, I would have to downshift and rev the motor not to lose speed on a hill. Anyway... I got this all together, and finally got it started... and it ran like crap. #4 cylinder wasn't even hitting, and #1 barely was. I could hold it wide open, and it would take probably 10 seconds to rev up high, and sputtered and popped all the while. I decided to take it for a limp ride, see if anything cleared up. I pulled out of my road, and there's a hill I have to go up. I had it in first, and had to have it full throttle to make it up the hill. I got about 3/4 of the way and POW... the bike almost came out from under me, and it would have flipped. I honestly thought I had been hit from behind. I was looking in my mirrors to see the idiot that rammed me... but.. no one around. So I goosed it again... this thing is firing full on, on all 4 and it SCREAMS!!! I have 2 problems though..

1. Before tearing into it, when you start it, and about 10 minutes after, it runs and idles perfect. 1000-1100 rpms. After it warms up good, it would rev up to about 4 grand every time you pulled the clutch. It did this with the current set of carbs, and another set I tried. Now it is running better, and when you pull up to a stop light... it will rev to at least 5 grand. The carbs were completely redone with this last part, and the floats were all adjusted, but I haven't sync'd the carbs yet... could this be the problem?

2. I took it for a ride after I got it together today, and noticed about dusk... that I had no frikkin headlight! I went and bought a new one, but no go. So I got out the volt meter, and my battery is puting out 14 volts, but the plug for the light is cosistently only getting 8 volts. It's constant, and doesnt fluctuate between high and low beam. It's just not enough juice to light the candle. I didn't mess with this at all during the tear-down, but i did have this one wire above my fuse box, and I don't have a clue what it goes to. Everything seems to have a home around it. I checked it, and it has no juice with the key on or off..


Any help out there?
Tod

[chevy45412001]

wire

i think that is for the batt sensor? but deffinetly could be off on that one?

[trbig]

I don't see anywhere for it to hook up, but the wide clip right behind it with the green and yellow with a green stripe wires behind it go to the headlight. I tried disconnecting this, but it looks clean. Put it back together, and still just 8 volts.

Tod

[Mike F]

Just a thought but did you fit the XJ head with the XJ cylinders?

[trbig]

The XJ head is mounted on an XS motor. I capped off the holes for the YICS tube.

[trbig]

I'm not as worried about the wiring right now as the revving problem after it's warm. Any suggestions on that?

Tod

[Dragonrider]

Cam chain tension ok? Then sync carbs, check for vacuum leaks (if you find any, fix and sync carbs again). Check for sticking vacuum advance and/or blown pod. Vacuum advance line hooked up to the right port? (#2 carb NOT the vacuum ports on the carb boots).

Is this an XS wiring harness/frame? If it is, under the tank is the headlight relay...check connections to it...4-wires--1 12 V feeds in, one power from alternator to trigger the relay, 12V goes out another (when triggered), and one is ground. Then check the connector for the handlebar switch to harness for corrosion.

Do you have a reserve lighting unit (I know the specials had them)?

[skids]

The runaway revving is a symtom of the need to synchronize vacuum of the carbies.

Originally posted by trbig
I'm not as worried about the wiring right now as the revving problem after it's warm. Any suggestions on that?

Tod

[trbig]

DragonRider,

Everything on the bike is XJ that I have found except the motor case. The electronics, coils, and everything else appears to be XJ by the numbers on them. Cam chain is new and tight... unless it loosened in 50 miles. The vaccum advance is connected to the carb now, not the boot (Like it was). I will check for leaks tonight as well as have a stab at my first carb sync.
I don't know what (Or where) the headlight relay is on the XJ, nut it should be about the same place. I will dig in my book tonight and try to find it, then check the connector on the headlight switch. I have no clue what a reserve ligting unit is... so couldn't answer that one.
Thanks guys.

Tod

[DiverRay]

Tod,
I just looked at the picture. CHANGE THE FUSE BOX. Look in the tech tips, but My guess is a bad fuse holder. You can buy the new style(blade) fuse holders for about $3.00 each at almost any hardware or auto parts store.
Use the VOM to check voltage on both sides of the fuses. You may find one side is down. If it is, that is a bad fuse or holder.
Ray

[xj11john]

trbig,

My Xj had the same lighting prob, only i think mine only had 5 volts. the reserve unit it on yamaha parts site http://www.yamaha-motor.com/sport/parts/home.aspx
look at # 55 for the 82 xj, on electrical #2 selection.

it is mounted right behind the battery, is a black box-like rubber thing with a connector with about 10 wires coming out.\

good luck.

that is what was bad on mine.

[prometheus578]

"You... light up MY life..."

I have no clue what a reserve ligting unit is...

If your headlight burns out, the Reserve Lighting Unit turns on your High Beam, but runs it at a lower wattage. Your high beam indicator light also comes on, dimly, I believe, to tell you what happened.

[trbig]

I'm going to try the cheap fuse fix that JC showed me first. Figure it couldn't be bad to start off knowing that was right. My headlight won't come on at all, and neither is my high beam indicator, so either the reserve lighting unit is completely out, or it's not the problem. Gonna start with the fuses though.

Cheap Fuse Fix

I am still fine tuning my carb sync. I have fixed the over-revving problem finally though!! My number 3 and 4 carbs were drawing about 20 mb of pressure more than my #1 and 2 carbs! I am doing it with a single pressure gauge... just trying to get all the carbs equal to what #2 was.

[skids]

Yeah, using a single gage means a lot of swapping of hoses and rechecking! Someone once mentioned a way to use a single gage and a fish aquarium air maniford with the four-valve gizmo.

Originally posted by trbig
I am doing it with a single pressure gauge... just trying to get all the carbs equal to what #2 was.

[trbig]

OK.. Before I get hate mail... I realize I had it all bass-ackwards. I was trying to tune everything to #2 carb... and couldn't get #3 to move for some reason (DOH!!) But my #4 was a runaway. It's tough doing this with just one gauge.