Seized 155z

[Chickenwingz]

Hi guys, I was taking my x4r around for a spin in the backyard today and while in second gear with the clutch in at about half throttle it died and made some wierd noise, I kicked it over gently just to feel what was going on and it went down 3 times without compression at all but made some noises and by kick number 4 it was seized solid, I didn't kick it over once I felt it seize, I drained the oil and took the spark plug off and realised this.

can someone please help explain what could have happen, thanks!

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[Cordogs]

Not entirely sure why you engine seized but your spark plug suggest that carbon fouling is apparent, usually caused from being too rich, a faulty choke or an old - unclean air filter.

Was there any filings in the oil?

Also did you take note on how much oil came out?

Have you tried to pour a little fuel down the spark plug hole to loosen the piston?

 

[my67xr]

has it snapped the tip off the end of the spoark plug ?
cant see it too well.

it might have brocken a valve, collets, or retainer, it could have damaged the piston too
think the head may need to come off to diagnose it properly

 

[Chickenwingz]

the tip of the spark plug is still intact, hope i didn't damage the piston, its got less than 3 hours on it. It shifts through the gears fine so i think the bottom end is ok.

 

[Cordogs]

Not entirely sure why you engine seized but your spark plug suggest that carbon fouling is apparent, usually caused from being too rich, a faulty choke or an old - unclean air filter.

Was there any filings in the oil?

Also did you take note on how much oil came out?

Have you tried to pour a little fuel down the spark plug hole to loosen the piston?

Any answers to the questions above?

 

[Blender]

it may have overheated ? did you notice it running a little hot?

 

[Chickenwingz]

Not entirely sure why you engine seized but your spark plug suggest that carbon fouling is apparent, usually caused from being too rich, a faulty choke or an old - unclean air filter.

Was there any filings in the oil?

Also did you take note on how much oil came out?

Have you tried to pour a little fuel down the spark plug hole to loosen the piston?

I put all the oil in a clear 1.5 ltr bottle, it filled up about half but i did lose about 50 mls on the ground, should i put some filter paper infront of the oil to see what is in the oil? i haven't found any filing in the the oil from watching it pour and looking at it in the bottle. I haven't poured fuel down the spark plug hole yet.

 

[Cordogs]

750 mls sound pretty close to standard.

From your first post it sounds like its gone through 3 cycles before the compression and the got stuck!

I'm not entirely sure on why your engine would have no compression in the first 3 strokes then get stuck?

sounds like a question for the spanner spinners mate.

 

[rotn50]

Have you pulled the cam sprocket cover off to see if the cam chain is loose, I have come across stripped crank sprockets on which the cam chain runs, also the chains have a certain life or even less then a certain life before they stretch and jump teeth on the cam sprocket, id suggest removing the cover and also doing a quick timing check.

 

[timeeh]

Having a look at that pic it seems as if ground electrode (tip) has been crushed into the plug itself, which in turn means the piston has hit it (thats if i'm reading/seeing that pic correctly) To say that it's bad is an understatement if thats the case.

 

[my67xr]

i think we need a side on pic of the plug ?

if you put some petrol down the spark plug hole, add some oil too, or do you have any kerosene ?
i would start by taking the r/h cover off the engine, and the cam gear cover as mick suggested,
that way you can check things out better,easier than guessing

 

[GooseMan]

What kind of noise did it make? Something like gears crunching or a squeak, or a cam chain loose??

 

[Chickenwingz]

It was closest to a chain noise, I opened the cover and the top of the cam chain is solid with no play at all and the bottom is loose, I suspect the chain has got caught in between the case and sprocket in the bottomend, it happen to me when splitting the engine, the chain slid down and got caught there.

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[zwebx]

strange, hope your cases are okay

 

[zwebx]

i know of some one who has a spare 155z head laying around if your one is shagged.. and a spare piston (no rings though)

 

[my67xr]

so, any new news on the 155 yet ?

 

[Chickenwingz]

I've been away from home so I haven't been able to work on it, planning on working on it when I'm back.

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