FXR150 conrods breaking

[dangerous]

... ok, been thinking and I DONT think the rod was the problem.

IMO I think the stinking new piston disintergrated, the crank pulled the rod and pin down draging it around the crank smashing it through the casing... the rod then broke and the rests history.

[Sideways Sam]

OK,

I had thought she might be fixable but now I think I can trash just about the whole lot........

Here we go:

* - Shrapnel found everywhere, carb, exhaust etc

* - First sign was when I removed the plug which had the end completely destroyed

* - Crankcase smashed to pieces, originally I thought it was just the hole throught where the rod penetrated just behind the barrel but it has destroyed just about everything including smashing a large chunk off the front of the case

* - Barrel destroyed including crack right up one side and skirt totally missing (I found most of the skirt in the exhaust pipe)

* - Head cavity completely munted including 3 missing valve heads etc

* - Almost nothing left of the piston, most of it seems to be floating around inside the crankcase

* - Crank is a bit of a mess so probably won't be any good either

My guess is that the piston and valves came into contact, I don't know whether this happened before the piston lost it's conection with the crank or if the broken rod was a result of the piston hitting the valves.

Interestingly the rod broke at the top, unlike the other's I've seen which have broken at the bottom. By breaking at the top it could go up and down inside the barrel ramming the piston into the valves/head repeatedly which has obviously happened in this case.

Still don't know which comes first, the chicken or the egg..........

Has anybody ever thought about whether the coolong is adequate on these things? anybody run a temp guage?????? If they were getting too hot that could explain all manner of problems. Running too lean could cause similar issues, I think that may have been my problem.

[stanko]

That will cheer up dangerous !

[Sideways Sam]

That will cheer up dangerous !

Yeah, he got off lightly

[Skunk]

I wonder if that's a piston failure too? A few bits get in the way and all hell breaks loose. Seems the engine wasn't stopped very quickly either (speaking from MY experience with GL145).

[Bren_chch]

fuk me thats impressive!!

I'd bet your piston split apart first... your rod then carried the gudgen and whatever was attached down and back up again smashing the shit out of your barrel, then pushing all the side wall of your barrel back up in to the remainder of the piston and then on in to the valves until the rod broke... i guess we will never know for sure.

[dangerous]

OK,

FARK...................

[Bren_chch]

What carb and what main jet did u run?

Apparantly The FXR's are meant to have better than average cooling for oil.

[Rick 52]

Shit mate that is wicked I have never seen one in that state.
I hope you find something soon and the right price .

[koba]

That is fucken amazing!
It looks as though the head has been dinged many, many times...

[Bren_chch]

Seems the engine wasn't stopped very quickly either (speaking from MY experience with GL145).

Keep it pinned skunk! lol

[TZ350]

A little demonstration of the kinetic energy stored in a crank that has a few rev's on.

[Buddha#81:Me]

good effort........makes me want to leave my standard motor alone.

[speedpro]

The head damage suggests a valve, or a few, dropped before the piston stopped. The valves will eventually smash the piston which does not help the rest of the engine at all. I've seem a lot of engines with similar damage at various stages. Sometimes the piston is still more or less together and the head looks just like that.

Forged pistons anyone?? And what about a Carillo rod?? and "quality" aftermarket valves?

[dangerous]

The head damage suggests a valve, or a few, dropped before the piston stopped. The valves will eventually smash the piston which does not help the rest of the engine at all. I've seem a lot of engines with similar damage at various stages. Sometimes the piston is still more or less together and the head looks just like that.

Forged pistons anyone?? And what about a Carillo rod?? and "quality" aftermarket valves?

Yeah thats what I was thinking, same damage when my CB droped two valves.

forged, carillo... yeah right these engines are a malaisain run about only that spilled over to NZ, china parts only.