Valves got louder then BAM!

[bleeble]

Valves

Cylinders 1 and 2

Cylinders 3 and 4

I had some pictures of the top of the head/valves, but they turned out blurry. If you still want to take a look, they're here: http://s292.photobucket.com/albums/mm38/TheRealBleeble/GS750/Motor/

One thing I did notice is the clean spot on piston number two and the bottom of the head. I guess that "thud" was from the piston flying up and hitting the top?

EDIT: And that oil got on the valves after I took it off. Yes, the exhaust valves on cylinder 4 were black.

EDIT 2: Oh yeah, I didn't have time to pull off the oil pan yet. My school schedule is really kicking my butt. In fact, I have a paper I should be writing right now...

 

[Guest]

to my eye (only semi-experienced eye though) spies only that clean area on #2 that you mention as well
that's good news i think

next stage, take the barrels off, that should reveal some damage i expect

 

[Suzuki mad]

Try and get the barrel off the best way you can without damaging the externals of the barrel.

At that point you will know how bad the damage is.

Looking at the pictures oily No4 looks like the valves are slightly open. Thats only oil seals which are easy to replace. Looks like No2 has bumped the bottom of the cylinder head from the marks on the picton and the head. With the position of the pistons in the picture that looks correct so a little inconculsive at present as to what has happened.

From the look of the parts of the bores that are showing theres no damage from the piston at present so the barrels may be salvaged.

Suzuki mad

 

[bleeble]

Doooooom! :evil:

Oil Pan

 

[bleeble]

Piston 2

 

[bleeble]

Piston 2 (more)

Sorry about the quality. My digicam's battery died and I had to use my brother's phone. Looks like I'll be needing a new engine... :?

I'll take apart the rest of the engine just for kicks, now that I don't have to worry about not putting it back together correctly. I'll try to take some better pictures with my digicam too.

 

[TheCafeKid]

WOOOOOW that thing KASPLODED!

 

[bleeble]

Yeah, it looks like the rod broke then took everything else out. :-k

EDIT: And in case anyone else has the same issue with being unable to get things apart in the future, a bit of liquid wrench (penetrating oil) around the gasket edge really loosened things up for me.

 

[SabreJim]

Wow

Wow

Daaaamn I feel the pain just from following this thread . I am so sorry and yet thankfull for as Basecliff puts it.... the indulgence.

If the crank is still good then you just need to score a piston with rod and cylinder base. head looks ok ....

what was the cause of this mess? did you find the source ?

 

[catbed]

if that happened to me, i'd have to keep that piston and connecting rod for some fond memories.

i agree with TheCafeKid. that definitely KASPLODED!

EDIT: wait! first picture of post #46. You still got some cross hatch on the walls! Just throw some new pistons in and you be fine!

 

[tkent02]

So all of this happened just cruising down the highway?
I'm not buying it.

 

[bleeble]

EDIT: wait! first picture of post #46. You still got some cross hatch on the walls! Just throw some new pistons in and you be fine!

Are you serious? :shock:

So all of this happened just cruising down the highway?
I'm not buying it.

Well, that is actually how it happened. I don't have any reason to lie to you guys; it's not like you're my parents and I wrecked your bike. But think about it... the thud was probably the piston hittin the top of the chamber and the broken rod destroying everything in the immediate area. What I thought was valve noise was almost certainly the bottom of the connecting rod being loose on the crankshaft (seriously, there was about 1cm of play before I took it off. It's oval-shaped now). Loss of power? Maybe that was caused by the extra movement of the rod/piston, I don't know. Or maybe the loss of power was after the piston broke free and I was only running on three cylinders.

Just imagine the engine spinning at 5000 RPM. A piece of hardened steel comes loose and starts slamming into the aluminum block and steel cylinder walls. Not only does it have the inertia of all of the moving engine parts behind it, it also has the firing from three other cylinders and the mass of the entire bike and rider forcing things along through the drivetrain.

I'm not expert, but it sounds plausible to me.

 

[Nessism]

Bike must have lived a hard life, cruising at 5000 rpm doesn't cause engines to implode...unless there was no oil inside the engine

 

[catbed]

of course i wasnt serious, silly!

 

[tkent02]

Just imagine the engine spinning at 5000 RPM. A piece of hardened steel comes loose and starts slamming into the aluminum block and steel cylinder walls. Not only does it have the inertia of all of the moving engine parts behind it, it also has the firing from three other cylinders and the mass of the entire bike and rider forcing things along through the drivetrain.

I'm not expert, but it sounds plausible to me.

I'm not arguing the fact that all that damage resulted from a failure at that low RPM, only that that failure would have happened in the first place. There must have been previous cracks or other damage from over revving, running out of oil, running way too hot, something bad had to have happened previously.
Any engine can cruise FOREVER at half the designed RPM, and these engines are seriously overbuilt for the stock configuration. FOREVER.

Never heard of one just breaking without serious abuse.

 

[bleeble]

I'm not arguing the fact that all that damage resulted from a failure at that low RPM, only that that failure would have happened in the first place. There must have been previous cracks or other damage from over revving, running out of oil, running way too hot, something bad had to have happened previously.
Any engine can cruise FOREVER at half the designed RPM, and these engines are seriously overbuilt for the stock configuration. FOREVER.

Never heard of one just breaking without serious abuse.

Ah, I guess I just misunderstood your previous post. I'd have to agree that someone must have abused it (not me ) or something else must have gone wrong to cause this.

 

[bleeble]

I guess I forgot to post these...

Think I could still use the crankcase if I cleaned out all the metal bits?

 

[Nessism]

Think I could still use the crankcase if I cleaned out all the metal bits?

Sure! Use some JB Weld to glue the pieces back together.:shock:

 

[tkent02]

Sure! Use some JB Weld to glue the pieces back together.:shock:

Sure you can use it!
For a planter box!
Ashtray?
Too big for a paperweight, to light for a good anchor.
I know, sell it on Ebay!

"Ran perfectly when parked nineteen years ago."

 

[robertbarr]

That does explain the low compression, though...