Pop sound, followed by smoke during start sequence - what broke?

[ljlucas]

Hi all. Looking to get some insight from the more electrically-savvy of the bunch.

Scenario: 2012 model 1200cc, been in the garage here in Pittsburgh fora bout 3 months without getting used and I failed to put on a trickle charger. Tried to start up recently, wouldn't crank over but sounded close. Live on a hill, so tried to catch it in gear to no avail. A neighbor attached a handheld quick battery charger at the bottom of the hill - still wasn't cranking over after charging up, so we pushed it back into my garage. After charging fully on the trickle charger, I tried starting again, held the starter button for about 10s then heard an electrical-component sounding POP, then a little bit of smoke came out from just under the tank in the center of the bike towards the handlebar end of the tank with a distinctive but not terribly strong burning smell that abated quickly. I saw that most electronics still worked, so I tried starting again, wouldn't turn over again, but it seemed like it could given enough tries. Haven't had time to check all the fuses but suspect fuses don't pop and smoke when blown.

Question: So what was the pop sound? Ordered a new battery, arriving on Friday, is there anything I can do to check for damage in the electrical system in the meantime?
Thanks!
Lenny

 

[JamesGang]

Welcome to the forum, ljlucas. Sorry that I can't offer any advise but someone should be around shortly that may have some idea's.

 

[hulkss]

Did the bike backfire out the air intake? Not uncommon after failed start attempts.

 

[~TABASCO~]

Take off the right side cover and give it a good look over, make sure its not an obvious battery issue, Etc .... I then would look at and check the fuses first (on the right side in the two black boxes). If those are ALL good, I would move on to the starter relay with the red on it located in the top left area. (looking directly at the side panel) You can check that with a meter or even a test light.

still not working.... post again more info after.....


When you tried to start it for 10 seconds, did you hold the throttle wide open in a "hard start" situation ? Or did you leave it closed ?

 

[Sierra1]

Check for signs of rodents also. They've been known to f some s**t up with similar symptoms.

 

[VRODE]

Check for signs of rodents also. They've been known to f some s**t up with similar symptoms.

This. Also, lift the tank and check the air filter. If it was a backfire thru the intake, it should show up on the air filter (a burned spot). Fresh gas, a fully charged battery and wfo throttle should get you going (assuming there were no fried electrics)

 

[Sierra1]

. . . . (assuming there were no fried electrics)

'Cuz if a mouse chewed up a soy covered wire, and that wire touched the frame, it would explain the "pop" & smoke.

 

[WJBertrand]

A loose or poor battery or starter solenoid connection can arc making a popping sound and letting smoke out of the wires.


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[mran]

Id pull the tank and air box look for damage to any wiring. Smoke can be serious ive seen harnesses go up in flames before. Also check the air filter coukd be a rats nest. Sucked in bent valve blew shit out the air box. Unlikely but when your that far any way. You rly dont want a electrical fire...

 

[mran]

Could be a hard start too but its really worth checking when you see smoke..

 

[Longdog Cymru]

Starter relay or main fuse perhaps?

 

[Jdubco]

what did the smoke smell like, electric smoke has a pretty distinctive smell over a fuel/backfire type of smoke

 

[Squibb]

Firstly welcome along, not the most auspicious start to S10 ownership.

Have you checked for codes, available through the dash on a 2012?

From a distance, this sounds like a classic hard start to me, exacerbated by the dead battery, with just a spit back from the inlet for your trouble. Check the air filter for witness, along with all the fuses & relays - check the fuses with a meter in situ, not by eye. If all OK/replaced, then try a WOT start up with the new, fully charged battery; max 10 seconds on the start button, with a lengthy pause between attempts to avoid damaging the starter motor.

If this doesn't deliver after several attempts, then I would be checking the cam timing, in case the chain has jumped the sprockets, along with the decompressor & CCT, then drop in some new spark plugs. Hopefully this won't be necessary.

 

[AusTexS10]

Welcome. I don't have much to offer that others haven't already. The one thing you said, though, that struck me was that the burning smell abated quickly. In my experience (including 4 years as a USN Electronics Technician), most burnt electrical component smells don't abate quickly. Maybe not as strong, but they typically don't go away that fast, whereas odor from something like a backfire would tend to dissipate quickly since it was the result of ignition of the vapor that could otherwise leave an odor. Just a thought. Good luck with your troubleshooting, and let us know what you find.

 

[ljlucas]

Thanks all! So far no luck after checking fuses (visually) and installing a new battery. There was a darker spot on the air filter. No evidence of rodents, consistent with being garage kept. Cleaned the filter and tried again, popping sound appears consistently after the second or so cycle of the start while holding the starter button then just tries cranking without more popping. What's the "hard start"? Is that a wide open throttle (assuming that's what WOT and WFO means) during starting?

 

[hulkss]

Did you store the bike with gasoline that has alcohol in it? There is a problem with it called "phase separation". Corrosive slime will form in the bottom of your fuel tank and plug up the fuel system.

 

[Squibb]

Just use search - countless posts about hard start & methods of overcoming potential flooding of the cylinders.

Fuses must be checked with a meter for continuity, not by eye. Invest in a meter, they are inexpensive & will save you time & heartache.

Have you checked for codes yet?

 

[ljlucas]

Following up. I ended up just taking the bike to the local shop. They determined that the timing chain skipped and likely caused some valve damage that is still being diagnosed and fixed. Has anyone had this happen? This happened after starting it up for the first time in a few months after sitting in the garage throughout a typical northeast winter. I never usually do anything special to winterize it, since I ride it into early December and bust it out again in March and never had any issue. Are there any known issues with the timing chain? Otherwise, I'm racking up quite a stupid bill at the shop for the fixes.

 

[RCinNC]

Your cam chain tensioner likely failed. The one that's on a 2012 model has been superseded twice with newer updated models. There are several posts in here about the cam chain tensioners on pre-2014 models failing. If they fail, the timing chain loses tension, which can allow it to skip a tooth on the cam gear and wreak havoc.

 

[gv550]

Earlier bikes did have problems with the original cam chain tensioner, several reports on here over the years of engine failure due to cam chain jumping a tooth or two.