Engine Popped, now wont start

[DarthVirilus]

I recently had new gaskets installed and it was running perfectly for a week until I was riding down the road when a loud pop came from my engine and completely turned it off.
Had to coast to the side and tried to restart it but it refused to start.
Any ideas?

[Water Warrior 2]

One of the rubber boots on the carb likely got blown off. There are 2, one for intake and one for the discharge side of the carb. I would check these first. They should be properly fitted with the clamps snugged to hold everything in place.

[jonathan180iq]

Which gaskets did you have replaced?

[DarthVirilus]

Clutch gasket and Oil seal from what the receipt the guy gave me says

[DarthVirilus]

He said he replaced another one but didn't give me the info for it

[DarthVirilus]

Also, when trying to start it, it sounds like something hitting the left side of the motor

[alantf]

Can you take it back to the guy who "fixed" it, and see if he has an explanation? If it's something that he fouled up, it should be under warranty if it's only a week ago.

BTW. Why did you need new gaskets? Was it leaking oil?

[DarthVirilus]

I found out the problem and apparently this is the first time it has happened to GZ riders
The piston was hitting the spark plug until it broke and why the engine went dead
Thank you all for your quick responses.

[Water Warrior 2]

Has the plug been changed lately?

[jonathan180iq]

Did the mechanic change the spark plug when you had the other work done? Unless the motor was recently rebuilt with non-factory parts, I can't see anyway that this would happen other than the mechanic put in a plug with too long a reach...

[mrlmd1]

DV - How do you know that? Did your mechanic take it apart already? If not, make sure you are there when the he removes the plug, or take it out yourself and see what he put in if he changed it.. If the plug was too long, it would hit the piston and the rebuild is on him.
Why were these gaskets replaced? You didn't answer alantf if it was leaking oil.
How long have you had this bike? Did the previous owner do that (change the plug) just before you got it? If that's the case, you may be screwed with the cost of a rebuild unless you can go after him.

[DarthVirilus]

The gaskets were replaces because the engine completely stopped working, I don't know why but he ended up getting it running again and it was fine for about a week
I just replaced the spark plug but it is still not starting, just making a tapping sound in the engine like it's not firing up

[DarthVirilus]

Oh, and it was the same spark plug from the previous owner from about 2 years ago
I never changed it until now

[alantf]

The gaskets were replaces because the engine completely stopped working, I don't know why but he ended up getting it running again

Well....the only reason that I can see for replacing the gaskets is that he had to get into the engine to do some work, so he fitted new gaskets when he put it back together (which is the correct thing to do) But what work did he do in the engine? The answer to this is likely to show us what the problem might be. ;)

[DarthVirilus]

Alantf, I have read a few of your forums so I think you will understand pretty well
I just replaced the spark plug and the samething happened to the other one, something is banging into it causing it to bend
On top of that, the engine will no longer even turn over after, again, a loud pop

[jonathan180iq]

If he changed the head gasket with something thinner, it would have essentially lowered the spark plug deeper into the recess and that could have caused the contact... I don't really know how else it could have happened, assuming the mechanic isn't just bull-shitting you...

Does anyone know the internal clearance between the piston and plug head?

Darth, did you pull the spark plug yourself or are you going solely on what the mechanic told you?

[DarthVirilus]

Myself

[DarthVirilus]

As far as the gaskets go, I have the receipt and part number, they are the same parts as the factory

[jonathan180iq]

Can you get a photo of the plug? Was it just the electrode or the whole end of the plug?

[DarthVirilus]

The first plug, the entire end was lopped off
The new one, it was just bent

[alantf]

Have you checked that it's the correct plug? It should be NGK DR8EA or equivalent.

[DarthVirilus]

Yes, I got the exact plug

[chandlerbingfl]

All I have is that this doesn't make any sense unless there is something ON TOP of the cylinder....a metal sliver or something.....

If the correct part numbers have apparently been used this is the only thing I can think of that would alter the clearances between the plug and piston....

chandlerbingfl

[raul10141964]

broken valve

[DarthVirilus]

Update: The Exhaust Valves broke off and destroyed the piston

[isaac]

How many miles were on it?

[Goose51683]

I was gonna say the same thing, thats the EXACT same thing that happened to me. Looked like the spark plug was hitting but pull it apart and it was a broken valve.

[Goose51683]

Isaac, mine had less that 6k when it happened.

[mrgz250]

you are problem running the engine to hot loose head bolts low oil missadjusted valves if the pipes going to the head
are discolored its because dirty air filter & need to open the air screw up a little & use a NGK dr9ea plug. Just a note for the gz250 owners ck the oil to see ir it starts to turn black aftera oil change 50 to 100 miles use suzuki oil & filter only
Ill say it again mine is new condition 80k 2000 13.5 yrs lol love your bike use it but dont abuse it

[raul10141964]

do not trust MRGZ250 he is spanning all the treads

[Goose51683]

Welcome to the club. I'm working on my broken valve issue as
Well