Starts now, but why wouldn't it before?

[brucealmighty]

1982 XJ1100 Maxim owner. So, I cruise on down to the pharmacy (about 10 miles away). After dropping off my prescriptions, I figure I'll gas up the bike while waiting for the scripts to be filled. Head over to the Shell station across the street. Shut off the bike, fill 'er up, go to restart and it doesn't start. Cranks over. And cranks and cranks and cranks, but doesn't fire up. Now I know I living on the edge here by using a battery that is much too small for this bike. It was a quick-fix replacement, and as long as I keep it on a float charger when not in use, I've been okay with it for a while. But now I figure, I've pushed my luck too far. Maybe the charge is down a bit and it's putting out enough to crank the starter, but not make a strong enough spark to restart the engine, though that shouldn't be difficult since the bike was already warm and had only been off for less than five minutes. I figure I might as well get my meds anyway before I start contemplating my next move, which just might be a 10 mile walk home. So, I push the bike over to the curb, and go back to the pharmacy to get my pills. I'm gone maybe 15 minutes. I go back to the bike and figure I'll give it one last shot before I start walking, even though the battery is now really run down. And what happens? Bang, it starts right up! Well, needless to say I am much relieved. Still I am perplexed. Why wouldn't it start before? If it was from insufficient battery charge, it sure didn't get any stronger as I was draining it. That would seem to indicate that it was a fuel problem. Don't know. Maybe some one has some ideas before I start looking for problems where there aren't any.

[TopCatGr58]

Here's my theory/guess!?

Hey Bruce,

The tip over switch may be going on the fritz! The TCI requires about 10.5 volts to fire, so it's not necessarily the coils as the TCI controlling the coils that can cause starting problems when the voltage drops too low! IIRC the tipover switch will allow the engine to crank, but won't supply power to the TCI! It's under the gastank, and simply unplugging it is the way to bypass it!

Otherwise, I would think that you weren't totally out of gas when you stopped to refuel. Did you happen to smell fuel during the extended cranking no start episode? Did you try to use the choke/enrichener? A warm engine needs less fuel than a cold one. Perhaps it got flooded, and once you let it sit a while, evaporated and allowed it to fire with the proper air/fuel mix?
Or, moving it from sidestand, back up, etc. sloshed the tip over switch around anough to deactivate it, allowing it to start!?

Take a voltmeter, and put it on the + of battery and to frame ground, and then start the bike and see what the voltage drops to! IF it's 11 or more, then that small battery is probably still okay, and it was something else that caused it not to fire!
T.C.

[brucealmighty]

Tip over switch? As in, if the bike tips over, the switch prevents the engine from running? I will check that out. Yes, during the extended cranking/no starting period, I thought I smelled gas, so that's what leads me to think that it was flooded. We're all so used to driving cars and even bikes that are fuel injected so we don't have to diddle a choke to just the right mixture. I'm always wondering if I have it right. If I'm having trouble starting it, I always wonder is it too much choke and it's flooding, or too little choke. I know when the engine is warm, it shouldn't have to be choked at all, but after refueling, it didn't seem to want to fire so I gave it some choke, which I probably shouldn't have. It seems lately it's developing a habit of not wanting to restart even when it's warm and then starting with a little bit of choke. I can see that the carb intake boots are cracked and so that may be the culprit as it may be sucking in some air, causing a too lean mixture.
It's always an adventure, ain't it?

[Jerry]

This is a classic symptom of a bad kick-stand switch. The XJ uses an interlock system that was supposed to prevent you from driving off with the kick stand (side stand to some) down. There is a switch on the kick stand that has 3 wires coming out of it down by the spring that keeps the stand up. Follow these wires up to just behind the gas tank. Unplug the connector, then on the bike-side connector, hook uo a 3-way piece of wire and plug it into all 3 connections. I used 1/4 inch male terminals and speaker wire to make my 'jumper'. This makes the system think the stand is always in the up position.

Switch is no longer available from Yamaha.

From personal experience, the other thing you can do is jiggle the switch plunger; at some point you will hear a quiet click as the switch trips a relay and the bike will start. I suspect that some small vibration happened when you moved the bike which caused the switch to trip enough to let the bike start. Sometimes flipping the stand up and down a couple times will do it. Problem will only get worse, btw.

If you do this mod, be careful not to ride off with the stand down, results can range from embarasing to dangerous.

If you have already done this mod, suggest you look at 2 other items: kill switch, shich should have the contacts cleaned every couple years, and another XJ-unique switch which is in the clutch lever housing. This small pin switch tells the system when the clutch leves is pulled in, idea was to not let the bike start if you were in gear with the cluch out. Two wires come out of this switch and go into the headlight shell. Jumping the bike-side connector defeats the switch. This one is not normally a problem, same with the kill switch, but the side-stand switch is a known problem area. Good Luck!

PS...If my XJ is warm, it starts easier if I hold the throttle wide open when I crank, When the bike fires I can let the throttle go back to idle.

[brucealmighty]

Excellent suggestions and much appreciated. I will do as you suggest right now and let you know the results. Thanks.

[brucealmighty]

But wait a minute, that doesn't make sense. The kickstand kill switch is for preventing you from putting it in gear with the stand down, which is does. Several times I've lowered the stand with the clutch engaged and the engine dies. But that's not what happened. The sidestand switch won't prevent the engine from starting if the bike is in neutral and the clutch is engaged. It should still start even if the stand is down. That is usually how I first start the bike in the morning. In this case, wouldn't it seem more likely to be the switch in the clutch lever housing? If that switch is telling the sidestand switch that the clutch is disengaged, then the bike wouldn't start.

[Jerry]

A bit more trouble-shooting detail:

The Neutral light circuit also ties into the interlock. If the green Neutral light comes on, chances are the Neutral indicator circuit is fine.

You can check the clutch switch by unplugging it in the headlight shell and putting a continuity meter across the 2 wires. Can't remember which way it goes, but clutch in / clutch out will give you continuity one way but not the other. As long as it is different one way, the circuit is probably OK.

I don't know of a way to test the side stand switch without jumping all 3 wires. However, you can put the bike on the center stand, ignition on (engine not running), and move the side stand to the down position. You should hear a relay click. If you don't, wiggle the plunger of the switch a bit. My guess is that you will soon hear a click. At that point the bike will start; unless you hear the click it won't. At least that is how it worked on my XJ, but considering the side-stand switch feeds into 3 circuits my failure may not be identical to others.

I also replaced my clutch lever switch; is is part of a cable assembly and cost was - IIRC - around $8.00. Until then I had jumped the bike-side connector with a piece of wire. Problem could be in this switch, which is why I mentioned it, but feedback I get from other XJ owners indicates the side stand switch is more likely to be a problem than the clutch switch.

All of this applies to having the side stand down, which is how most people start their bikes, even if the stand is not on the ground. I get on, hold the bike upright, fire up, then flip up the side stand. Other option is to put the stand up before you fire the bike, which should take the side-stand switch out of the equation.

BTW, don't choke the XJ when it is warm. Most people I've spoken to report results similar to mine; hold the throttle wide open until the bike fires, then release it to go to a normal idle.

[brucealmighty]

NEVER MIND! Found the problem. Happened again today, and I figured well, that's it then. It's got to be just some sort of a loose connection and I'm going to find it. So, I took off the seat and commenced checking every connection until I found the culprit. There was a loose main fuse wire. I tightened it up and secured it with electrical tape. Bike starts just fine now. Thanks for all the info.