Cause of Snapped Spark Plug?

[Yutchadol]

First of all I wanna say my non running '92 GS500 is being sold. I have to thanks everyone on the board for answering questions I've had specially Adidasguy & Weedahoe. 


With that being said I got a 2004 Yamaha Virago 250 on Craigslist. It's a good town runner up until today. On my way to my motorcycle class I was going from 1st to 2nd but gear went into neutral. So I quickly shift it from neutral to second & all of the sudden the bike died. I had to park the bike, take the bus & walk back home, got my mom's car & made it to class 40 minutes late & I was dismissed. $100 gone.

After all that I went back to the bike, push it for about 1 hour to the shop. Mechanic took off the spark plugs. The left one was 1/4 snapped. Seems like the broken pieces just sitting in the cylinder. I got a "worse come to worse" quote for $950 in parts (replacing the whole rear cylinder)  & $450 in labor. But they will do a tear down for $200 & hope to just replace the broken parts.

Now I'm wondering what could be the cause of the snapped spark plug. I've had the bike for 1 week. Bike is a '04 with 3,000 miles 200 of which I put on in the week. Could it be that the last owner did something that cause this? I bought this bike due to the low miles & thinking it would be no problem (at least nothing major).

Anyway I've had a day & it's only 12:40pm. Thanks for reading & your answers in advance  I'm a go take a nap

[skunkteeth]

I'm kinda confused, what part snapped? Insulator tip/electrode? Or terminal end?

I had an image in my head of the terminal end snapping, which shouldn't leave much in the cylinder except the threaded portion.

And as a side note I would rather buy a bike from '04 with 30,000 miles compared to 3,000 miles, otherwise it sat quite a bit without much attention or maintenance (not saying your bike, but some)

[mustangGT90210]

It's possible the PO over tightened the plug on install and it's been cracked a long time

[Yutchadol]

I'm kinda confused, what part snapped? Insulator tip/electrode? Or terminal end?

I had an image in my head of the terminal end snapping, which shouldn't leave much in the cylinder except the threaded portion.

And as a side note I would rather buy a bike from '04 with 30,000 miles compared to 3,000 miles, otherwise it sat quite a bit without much attention or maintenance (not saying your bike, but some)

The electrode part snapped. And you are right thinking like that. Maybe this bike has been sitting.

[Yutchadol]

It's possible the PO over tightened the plug on install and it's been cracked a long time

This PO sucks man. I called him & he said he was in class & will call me back. I messed up for not making a copy of the ad though. He said bike was in perfect condition.

[weedahoe]

Ive seen the electrode parts of plugs explode and break before with no warning or reason. Sorry I cant tell you why but do know your are the only one

[adidasguy]

I doubt there is anything the PO could have done or not done to cause a spark plug to snap.
Sometimes things just happen.
I had one go intermittent - a new NGK - and no idea why. So I suppose an internal defect in a plug could cause it to explode or fracture.

[wayne242]

Faulty plugs or more common then people think. They can be damaged in shipping and you will never know unless you look at them with magnifying glass for cracks. I have found a few cracked, and always look at them be for install. Even a cracked plug may run months be for coming apart from heat and pressure.

I highly doubt the last owner could for see this, a plug is only a couple bucks so doubt he supper glued it and stuck it in there.

[ohgood]

..... I got a "worse come to worse" quote for $950 in parts (replacing the whole rear cylinder)  & $450 in labor. But they will do a tear down for $200 & hope to just replace the broken parts......

before i start a new rant about shitty mechanics and over pricing....


why not just replace the spark plug and ride it ? if the plug is broken, fine. remove the plug and run the starter a few revolutions with the plug removed. if there are any bits to fly out, that's a good hole to fly them out of.

put a new plug in and ride it. remember, you're screwing a very fragile, very thing walled steel and ceramic assembly into an aluminum head: once the crush washer crushes - STOP.


i don't get where the $950 comes from, unless he has a boat.

[codajastal]

..... I got a "worse come to worse" quote for $950 in parts (replacing the whole rear cylinder)  & $450 in labor. But they will do a tear down for $200 & hope to just replace the broken parts......

before i start a new rant about shitty mechanics and over pricing....


why not just replace the spark plug and ride it ? if the plug is broken, fine. remove the plug and run the starter a few revolutions with the plug removed. if there are any bits to fly out, that's a good hole to fly them out of.

put a new plug in and ride it. remember, you're screwing a very fragile, very thing walled steel and ceramic assembly into an aluminum head: once the crush washer crushes - STOP.


i don't get where the $950 comes from, unless he has a boat.

LMFAO, oh and +1

[wayne242]

..... I got a "worse come to worse" quote for $950 in parts (replacing the whole rear cylinder)  & $450 in labor. But they will do a tear down for $200 & hope to just replace the broken parts......

before i start a new rant about shitty mechanics and over pricing....


why not just replace the spark plug and ride it ? if the plug is broken, fine. remove the plug and run the starter a few revolutions with the plug removed. if there are any bits to fly out, that's a good hole to fly them out of.

put a new plug in and ride it. remember, you're screwing a very fragile, very thing walled steel and ceramic assembly into an aluminum head: once the crush washer crushes - STOP.


i don't get where the $950 comes from, unless he has a boat.

I agree with the above, you can buy a good used engine to put in it for much less then 950. 450 labor, diffidently not a place i would take my bike to. did not even cost no where near 450 labor to put head gaskets on my friends 07 truck, and a bike is much much more easy to work on.

[Yutchadol]

Thanks for the replies. The mechanic printed out this sheet of parts (cylinder head assy $452.95, piston std $75.95,etc.). He said he'll charge $200 for the tear down & see what's broken in there. Not meaning I will end up paying $694.36 in parts unless the whole thing is broken. So about $700 in parts not $950. I was tired. So I'll probably just pick up a spark plug & get the broken bits out somehow. Thanks guys 

[Yutchadol]

Apparently I'm not the only person this happen to.

http://www.motosport.com/cruiser/2004-yamaha-virago-250-xv250--NGK-IRIDIUM-IX-SPARK-PLUGS

Make me feel a little better 

[yamahonkawazuki]

..... I got a "worse come to worse" quote for $950 in parts (replacing the whole rear cylinder)  & $450 in labor. But they will do a tear down for $200 & hope to just replace the broken parts......

before i start a new rant about shitty mechanics and over pricing....


why not just replace the spark plug and ride it ? if the plug is broken, fine. remove the plug and run the starter a few revolutions with the plug removed. if there are any bits to fly out, that's a good hole to fly them out of.

put a new plug in and ride it. remember, you're screwing a very fragile, very thing walled steel and ceramic assembly into an aluminum head: once the crush washer crushes - STOP.


i don't get where the $950 comes from, unless he has a boat.

or you can advance the piston to a bit below top, rig a tube to a small van and suck the bits out.  this DOES work. or those tiny telescoping magnets work wonders too.

[Yutchadol]

Great ideas! I will do the magnet one. Hopefully nothing is broken in there. I guess there's no way of knowing that unless I open up the head.

[MarkB]

i don't get where the $950 comes from, unless he has a boat.

Bits of spark plug rattling around in a running engine could have damaged the piston and/or cylinder.  That said, I don't see that the OP is risking breaking anything that hasn't already been broken by vacuuming out the cylinder, replacing the plug, and trying to run it.

[crzydood17]

Yep move piston to about half way and inspect with a light, grab a cheap telescopic magnet and move it all over the piston and especially around the rings (this is why you want it about half way up so that you can reach everything). After you have magneted all you can magnet. Move the piston up and down a bit and try it once more. Move it back to near TDC and vacuum the port out. You can also try to get it on an exhaust stroke to get the exhaust valve open and allow some air to flow around in the cylinder that might stir something up. Hit it with some canned air to blow any remaining bits around and move the cylinder back to half way and go around with the magnet again. Take pictures post results.

[Yutchadol]

Update:

I picked up some spark plugs & a telescopic magnet, went to the shop to start the bike but noting. I did learn that the rear cylinder spark plug hole is tighter than the front. Where the front one I can screw in with my hand, the rear I needed to borrow tools from the shop. So my plan is to leave the bike at the shop & have them work on it.

[ohgood]

First of all I wanna say my non running '92 GS500 is being sold. I have to thanks everyone on the board for answering questions I've had specially Adidasguy & Weedahoe. 


With that being said I got a 2004 Yamaha Virago 250 on Craigslist. It's a good town runner up until today. On my way to my motorcycle class I was going from 1st to 2nd but gear went into neutral. 1) So I quickly shift it from neutral to second & all of the sudden the bike died. I had to park the bike, take the bus & walk back home, got my mom's car & made it to class 40 minutes late & I was dismissed. $100 gone.

After all that I went back to the bike, push it for about 1 hour to the shop. 2) Mechanic took off the spark plugs. The left one was 1/4 snapped. Seems like the broken pieces just sitting in the cylinder. I got a "worse come to worse" quote for $950 in parts (replacing the whole rear cylinder)  & $450 in labor. But they will do a tear down for $200 & hope to just replace the broken parts.

3) Now I'm wondering what could be the cause of the snapped spark plug. 4) I've had the bike for 1 week. Bike is a '04 with 3,000 miles 200 of which I put on in the week. Could it be that the last owner did something that cause this? I bought this bike due to the low miles & thinking it would be no problem (at least nothing major).

Anyway I've had a day & it's only 12:40pm. Thanks for reading & your answers in advance  I'm a go take a nap

ok, rethinking this one and ewww, not good:

1) could be the stator or whatever generating system / timing system this bike uses sheared it's key, or died, or ... . i don't know. a problem, yes, but not related to the sparkplug, or assumed damage from the sparkplug (i think NONE), because you put a new one in, and it didn't start.  on to " 2 "...

2) the mechanic did it. he twisted hard on it, when the head was cold, and didn't care if it snapped. it takes 5 minutes to tap in a screw extractor, and turn out the threaded portion of a sparkplug. (for me anyway)

3) see " 2" , the mechanic killed it, caring or not... and whoever put the plugs in didn't use anti-seize, or over tightened it. i'm still blaming the mechanic because they lie, at this point.

4) you put 200 miles on it. that's about enough time for a tac-welded stator/alternator/something to work loose, and a missed shift to completely dislodge whatever amazing piece of sensing (ignition circuit) to fall off or fail.


so, i'd pull the side covers, look for really bad things ( trademarked phrase !), and go from there.

ps- i hate to be negative, but the bike is not worth the cost of fixing at that mechanics' shop. when the guestimate is $1000, it's rarely, if EVER less than 75%.

option:

push the bike into a corner, buy another GS500, love that gs, and tinker on the 250. remember, it costs -nothing- to do -nothing- to a machine. time doesn't matter, if it sits 5 days or 5 years. dump some oil in the cylinder if you plan to resurect this bastion of bascily boring transport at a later date, and move on.

[ohgood]

oh, look ! your karma has paid off. a fello twinner is condiering selling his, fantastically fine gs for a reasonable price. and right next door to your thread !

road trip  ?

fly n ride ?

http://gstwins.com/gsboard/index.php?topic=63333.0

start the adventure