1982 XJ550 Seca dies…won't start…starts! Electrical-shmectical

Plot:
A friend, we'll call 'em Dee, is riding the "new-to-me" '82 XJ550 Seca on beautiful Sunshine Coast backroads. Pulls a u-turn at destination and…bike dies, suddenly. Mayyyyyybe user error (slow speed clutch, not enough gas?), but suspicious. Roll to a stop, neutral, kill switch is still on "run", side stand up, clutch in, push the starter…nothing. Starter not turning, engine not turning over…just the sound o' the wind in Dee's ears. Wait half a minute, push starter…nothing. Sigh, oh well, we're here, let's have a caesar (Canadian cocktail to match our red Canadian Seca), leave it overnight. Try in the morning, prepare for the worst, but a proper Seca breakfast: petcock on prime, choke fully on, don't give it any gas, and prepare for nothing to happen and…it starts! Praise be.

Woohoo, Dee makes it back to the ferry, shuts it off, fingers crossed…it starts! Well, get it to the home garage and investigate. Dee and me charge the battery with a smart charger to full, give it a proper check-over and…it starts! Let it idle for a bit, choke off, running OK but idling a bit low, let's see if it stalls and…it stalls on the stand…oh well, let's start it up again and…nothing. Push the start button…nothing. It's baaaaaaack.

Charge the battery to full again and wow, the starter button engages the starter motor, engine turns over for ten seconds, but doesn't catch. Stop, stay calm, relax. Pull the choke out, ignition on, kill switch on "run" and…nothing. Starter motor not turning over. Let's pull another battery from my bike and hey, it turns over…but doesn't catch. So:

Clues:

1. Turn on ignition, put kill switch to "run" and we can hear a subtle click. Open up a seat and, I believe, the relay is that little cube visible just aft of the tool tray. We can hear and feel it click when moving the kill switch to off [click], then to run [click], off-to-run [click].
2. Ignition on, side stand up, bike in neutral, kill switch to run, push starter button and small click heard (and felt, when touched) from starter solenoid next to battery.
3. Start motor turns when battery 100% charged. When engine doesn't start after ten seconds, stop pushing starter button, wait a few seconds, push starter button again and…no starter motor, just the click of the solenoid.
4. Ignition on, kill switch to run, bike in neutral, side stand up and short the solenoid contacts with old screw driver and start motor engages, but now engine doesn't catch.
5. Pulled plugs after no-start scenario: two slightly wet, two dry, looking pretty clean overall.
6. Battery: AGM sealed type no maintenance, from previous owner, appears to hold charge
7. Bike has been running since purchase a week ago.

Questions:

1. Two problems interfering with each other? Electrical (starter relay, solenoid, starter motor?) and flooded engine or spark plugs and/or coils faulty?
2. It only seems to not start after it stalls. Causation or correlation?
3. Not enough electricity to starter motor and coils/spark plugs at once?
4. Can't we get more than ten seconds of turn-over with a fresh-charged battery?
5. Do all old motorbikes spit in the face of Occam's razor?
6. What time's the bar open 'till?

Notes:
Only been wrenching on motos for a year now, but learning fast, getting in deeeeeeep. Ask me about being stranded in Oregon on my Honda CM400, or the 12th breakdown on my KZ650, or the weird suspension on my Suzuki GS650G. Long time lurker on XJBikes (well, about 40hrs of reading in the last 7 days), first time poster.

 

Still original fuse box or upgraded to blade style fuses? I'd start checking voltages there first and see where it takes you

 

This I think. Remove check and clean starter motor (refurb guide is on this site somewhere) fit new solenoid (they're cheap enough). Then check valve clearances - I'm convinced poor attention in this area can cause starting issues. After that it's a carb strip..

Bon chance.

 

I agree with rebuilding the starter, but also check:

Sticky Sidestand switch. Easy to check, easy to fix. Clean with electrical contact cleaner as you move the plunger, then lubricate with a silicone based dry-film lube.

 

Thanks everyone, stay tuned…going through these suggestions and closing in on the culprit(s). To start, yes, original fuse box—looks clean, but will check the voltages there. Next: pull the starter solenoid to take a looksey. After that (if needed): clean the starter motor—may just clean it regardless, after this problem is solved. Sidestand switch, too (although if in neutral it may not be related to the current problem, but always worth checking).

 

Can't wait for the sequel! Nice read.

Yes, do as you just mentioned. Then (if it was me) go through all of your electrical connections, make sure they are clean, tight and a little greasy (die-electric that is).

 

Update (actually did this a week after feedback from everyone): voltages seemed to check out, and in the interest of time I pulled the starter solenoid. Short story: it's not really repairable (I pulled / snapped some contact wires out trying to pry it apart). It did appear, however, that one of the two copper contact posts was more pitted and corroded than the other, which may have been leading to a loose connection (not fully contacted) connection (further exacerbated when the area was under heat stress?). Anyways, it's a $25 part online or $40 at my local shop (Modern Motorcycling), in Vancouver, Canada)—I bought local and had the bike running that afternoon.


Image shows original solenoid (left) and new (slightly stubbier) model on right. Had the same rubber mount and connector.

Now stay tuned for my next post / problem involving the crankcase and a whole lotta gas.

 

The start solenoid is the usual culprit, I had to replace mine it was intermittent problem ,and was corroded replaced it no more problem. Now as to your whole lotta gas ...your floats are not sealing ..needles are most likely grooved in seat ...Time to got the church of clean..