Pretty sure I blew up a cylinder (?)

[M42]

Went out to ride today. Everything was completely fine for hours of riding. Cruising along, downshift, half a second later BRRRRRRRAAAAAPPPPPPPPPPPP!!!!

Basically the bike is clearly running on one cylinder. While running, I can smell oil - not burning oil, just straight up raw rotella t6 smell. Nothing is leaking anywhere on the bike, at all. A hair under 15k miles. I did all the maintenance on time and didn't abuse it. The oil was even changed like 100 miles ago. Even rode with @Finesse on sunday and everything was a-ok. I'm gonna do some exploratory surgery sometime this week, and either I'll come out with some souvenirs, or it'll be something simple like a plug (unlikely though). I've basically never ever heard of a pregen blowing a motor... I don't know. Anyone have something similar happen?

Here's a video (NSFW swears)

Link to original page on YouTube.


I was having such a good time on the ride, too. Even pulled over to take some pics.




Waiting for the tow



not a good day.

[csmith12]

Dats a bummer...

[alex.s]

I'm sorry for your loss.

[alex.s]

i liked your swearing though.

[jkv45]

Hmmm...

That was an odd sound. Blew a plug out maybe?

[ninjamunky85]

Originally Posted by jkv45

Blew a plug out maybe?

Had this happen to me once. Sounded a lot like that when it happened. That would be the first thing that I would check.

[Skullz]

That is an exhaust sound so i would think the plug came out or something else happened on the exhaust side of things.

I had a car that blew the ceramic and electrode out from the plug and it sound pretty much like that sounds.

[alex.s]

could be the plug. doesn't sound like a blown crank. sounds like a hole in the engine. but its not leaking anything. i think plug is probably correct.

double check the threads on the plug hole before installing a new one if thats what happened. it may need a helicoil installed

[JohnnyBravo]

I didn't hear nothing pop, and didn't hear no loose motor parts bangin around, I'd go with aint dead, just needs a bit of fixin

[Sirref]

doesn't sound like anything majorly broke, sounds like a plug to join in with the chorus

[choneofakind]

That's exactly what it sounded like when my engine blew a plug out. Had to get the plug threading drilled out and a helicoil inserted. Not surprising it happened during decel.

How many miles on the bike?

EDIT: a hair under 15k

THATS THE SAME MIKEAGE MINE HAD!

[M42]

Haha, wow. So, in case it is actually the plug - how hard is it to put in a helicoil/timesert? All I know is the wiki says it takes forever and is super annoying. Like, hard enough I'd think about getting it done at a shop even though $$$$$$.

[csmith12]

lol... mn

[Ninjinsky]

It does sound like a pluggy, however with a bit of right hand they will usually keep running and limp home on one (been there) whereas yours sounded totally unresponsive.
These things are never on your driveway are they.
If its any consolation last week,after 6 trouble free years I took my car on a trip to Wales looking to buy a house. 5 pm in a village in the middle of sodding nowhere 250 mile from home it won't turn over, starter is burned out- kaput.(I used similar words to yours) I thought it was a battery but no, garage comes out and battery is fine, so we bump start it, and I drive home without stopping praying I don't run out of gas or stall on the flat. I nurse it home and this week it rewards me by failing its inspection on a rotten subframe which is no easy job to source and replace. All done now.
The thing is we always triumph in the end even when things look insurmountable rugged persistence in the face of adversity wins.

Keep us updated

[fishdip]

you sound mad bro

[choneofakind]

Yeah it's not hard at all... for someone with a full machine shop and some time on their hands.

I took mine to a shop because limited machine shop at home. If it had been at school instead of home, I would have done the work myself.

[M42]

So I just went and checked real quick- coils are good... Squashed my hands under the tank, checked the left plug boot, everything ok, checked the right, it wasn't seated. Got my hopes up that it was just a disconnected plug, but when I seated it and fired up the bike, it blew off again. Could see the front brake light cable bouncing from the popping down there. So yeah, sounds like the plug got wrecked at least. I'll grit my teeth and take it apart tomorrow to see what's up.

If the plug blew out but everything else is ok, I'm buying a new head. Messing around with helicoils in that tiny space is a bridge too far even for my near-infinite patience.

[choneofakind]

Take the head off and have the helicoil installed off the bike. That's what I did.

[M42]

I'm pretty broke, I doubt I'll be able to afford having any kind of work done at a shop, since it's 90/hr here. A head's like 70 bucks off ebay.

[Ninjinsky]

That's good news although it wont feel like it. Hold off buying a head until you have priced getting a helicoil done (if indeed it needs it, might not), since the head is coming off anyway I dont know which is the cheaper option but you know these cam bearings valve guides and such are good.

ps I see we are overlapping comments, crossed wires imminent

[choneofakind]

That's an option. Have you found any in good condition?

The other option is a machine shop. They'll be less expensive per hour than an automotive/motorcycle shop and are likely faster. Should be able to bring the cost down there. The head is flat and will bolt nicely to a drill press or mill. The spark plug hole is not perpendicular to the bottom of the head, but it is a straight hole, so that's not a huge issue for a machinist.

[Skullz]

Before you pull the head take a peek down the hole and see that you have threads, if the threads are toast then you'll need to do something about it but if they look good then drop a new plug in and see what happens.

Now if the old plug has some of the old thread from the head attached then you know you'll either need to helicoil or get a new head.

Personally i would see about having both plugs helicoiled as if it happened once there is a risk of it happening again.

[Finesse]

I curse everyone, I'm sorry

Get an R6

[Sirref]

Originally Posted by Finesse

I curse everyone, I'm sorry

Get an R6

nono R6 is for when you crash
cbr600rr is for mechanical failure

[Finesse]

^Hmmm, never heard that one.

SV650 must be for when your bike gets totaled but you didn't crash it.

Sounds like M42 needs an SV.

[Sirref]

I'm trying to get the cbr one kickstarted, I almost went for it myself but got a 300 instead

[Finesse]

Hondas suck.

[csmith12]

Originally Posted by Sirref

cbr600rr is for mechanical failure

replacing one set of problems with another set doesn't solve anything

[Finesse]

^he knows

[Sirref]

it's all about finding one that isn't jacked up in some way or another...patience, a virtue that comes in handy if you have it

[Finesse]

and especially when you do not..

[Klondike1020]

Patience and Perseverance . That will allow you to overcome.

Good luck fixing your stuff. all you spark plug hole stripping maniacs

[LoneRonin]

lol...love your commentary.

[M42]

Update:

Pulled out the boot on the offending side, it came up with the plug. Everything was very sooty




Plug threads looked alright, a few mms of the edges on the thread were dulled but that was it (lighter grey on the threads in this pic)




Boot end of the plug was bent, some threads straight up flattened (that divoted part)




Valves ok




Down the hole. Can't see the threads at any angle except straight on, so I have no clue if they're actually stripped. The little mirror on a stick I have is too wide to go down the hole, and I ****ing suck at using those anyway. It looked like there was a literal pile of soot at the bottom of the hole. Nothing glinting in it, though.





I yelled YOLO at the top of my lungs and threw in a new plug. It found the end of the thread without a problem, but I could only finger tighten it 1/4 of a turn before it stopped. Tightened it another turn or so with a wrench. I don't actually remember how far in the plug threads go on the bike, but they probably should go in a little farther when tightening with fingers iirc... turned the bike on, both cylinders worked, warmed it up, seemed ok. Sounds normal. I'm just not sure about the threads - I could wrangle the **** out of the plug with a breaker bar, but I don't want to strip everything/send aluminum bits down into the engine. I could leave it as is, but risk another blowout.

[alex.s]

it threads in at least 10 full turns before it hits the crush washer. if its not crushing the crush washer, it will come out again. don't overtorque or you'll screw the aluminum threads like you said and have to helicoil it (been there. not fun)

you could put some grease on the spark plug threads... should make it go in better. just make sure you crush the crush washer properly

[alex.s]

also that "pile of soot" is your piston top

[jkv45]

If the old plug was not completely seated for a while you may have carbon built-up on the threads below where the plug stopped.

I would take the new plug out and spray some carb cleaner on it and on the threads while you try to turn it down with your fingers. You could remove the other plug and put a mark on it (or the socket) so when you turn it in by hand so you know how many turns to expect before it is seated.

I've used carb cleaner before on plugs that had been in the engine for many thousands of miles and didn't want to come out. In that case you move it a little (until it stops) then spray carb cleaner on it, then thread it back in, then back out, then spray, repeatedly until it eventually comes out. Without doing that it would lock-up tightly after 1/16 turn, and most likely mess-up the treads if you used enough torque to continue to move it.

If that doesn't do it, look into a "thread chaser".

I wouldn't leave it how it is.

[Ninjinsky]

Obviously been loose for a long time and a lot of soot has built up as it worked its way out which will have clogged the threads somewhat. Since you don't have a plug tap you can file a vertical groove into the old plug threads and use it to clean out the threads. Insert till you meet resistance then keep adding a quarter turn and backing off out again. Hopefully this will gradually clear the threads until you reach the bottom.
If a couple of turns is the bottom then the threads are stripped anyway. You cant win them back because they ain't there. And you know what comes next

ps
ie more or less what jkv45 posted ^^^ while I was typing LoL except for making a chaser out of the old plug.

[dcj13]

Originally Posted by M42

... threw in a new plug. It found the end of the thread without a problem, but I could only finger tighten it 1/4 of a turn before it stopped. Tightened it another turn or so with a wrench. I don't actually remember how far in the plug threads go on the bike, but they probably should go in a little farther when tightening with fingers iirc... turned the bike on, both cylinders worked, warmed it up, seemed ok. Sounds normal...

That's encouraging! Especially considering the electrode is way up in the threaded hole instead of down lower where it should be.

If I were faced with your situation, I'd try to shove a toothbrush loaded with my favorite solvent down the hole and twist it in hopes of cleaning out the threads the best I could. (May be impossible due to overhead obstructions?). Then I'd put some grease or anti-seize compound on the threads, get the plug started straight, and run it in as far as I could without cranking too tight.

Worst case outcome: If the threads are yacked up, you're in for a helicoil job anyway.

Best case outcome: it goes in OK and you're ready to ride.

[dcj13]

Yeah, ok...

Jay and Paul's idea of chasing the threads is good.

Are long plug taps available for chasing threads in overhead cam engines? And would one have to pull the engine to gain access?