Engine went bang

[Oblivion]

So I'm having a little bit of a dilema. I took my bike out yesterday for a ride after not using it for a week or so. Checked the fluids, charged the battery and off I went. Pretty much went as normal until I went around 14ks from home when I heard a bang and the engine cut off completely.

Pulled over and checked if it would start. No go. Usually the starter motor ticks over, but in this case it was nothing. No noise whatsoever. So we managed to get it home, and I had a look over it.

The only thing that I can find that is different is that the clutch wont work. I put it into gear, and pull the clutch in, and the wheel won't freely rotate. And now there's pretty much no resistance on pulling it in either.

So, I'm thinking that the clutch exploded or something,

But its an 87' GN250. There are a few other problems that are wrong with it, There's a charging problem, the rear wheel bearings are shot as I just found out, and It needs new brake pads all around. We bought it cheap, but with this new addition to the list of problems, is it really worth fixing or should we just deregister it? Bear in mind, we paid the rego the day before all of this happened, and it is my only form of transport currently.

[Paul in NZ]

If you can do the work yourself it might be worth fixing.

Where did the bang come from

[Oblivion]

I'm not sure, but I'm thinking bottom end.

[bogan]

Its a GN, so my advice would be lie it down on the left side (guess you could put some pillows/tyres down for the other side), pull off the clutch cover and have a look. You could drain the oil instead of lying it down of course, but then you have to spring for new oil before testing.

If it's fucked, just give it to ducatilover, he's got a thing for GNs.

[Paul in NZ]

I'm not sure, but I'm thinking bottom end.

Bottom ends don't usually go bang without bits flying out of the engine etc.

Does the engine still turn over????

[Oblivion]

Its a GN, so my advice would be lie it down on the left side (guess you could put some pillows/tyres down for the other side), pull off the clutch cover and have a look. You could drain the oil instead of lying it down of course, but then you have to spring for new oil before testing.

If it's fucked, just give it to ducatilover, he's got a thing for GNs.

If I lived in Palmy then Id get him to have a looksie. :(


Bottom ends don't usually go bang without bits flying out of the engine etc.

Does the engine still turn over????

Nope doesnt turn over at all. Push the starter, it whines, then it sounds like it gets stuck on something.

[FJRider]

Pretty much went as normal until I went around 14ks from home when I heard a bang and the engine cut off completely.

Pulled over and checked if it would start. No go. Usually the starter motor ticks over, but in this case it was nothing. No noise whatsoever. So we managed to get it home, and I had a look over it.



Sounds more like major electrical short.

With the clutch gone ... it would not stop the engine from running.

[sinfull]

we paid the rego the day before all of this happened, and it is my only form of transport currently. Sounds like you really gettin more bang for ya buck !

[Oblivion]

Sounds like you really gettin more bang for ya buck !

414$ Worth :doh:


Sounds more like major electrical short.


With the clutch gone ... it would not stop the engine from running.

Well, Upon closer inspection, the flash unit is buggered, since the indicators are solid. But are there any other signs of an electrical failure that I should look for? Because the headlights run normally. Horn works, All of the lights work properly except the indicators.

[Akzle]

seized engine -OR- something gearbox has fallen off and dun gone got stuck.
stop pushing the starter button or you'll blow that too.

STRIP DOWN.

worth fixing? up to you... if it's in the head (piston melted to cylinder, dropped valve, ring made a bid for freedom via the exhaust port etc then it's new top end. fuck knows what they're worth.
if it's something clutchy, it's new gearbox. (see above for value estimate)

either way. stop fucking wit it. pull it apart.

[bogan]

Well, Upon closer inspection, the flash unit is buggered, since the indicators are solid. But are there any other signs of an electrical failure that I should look for? Because the headlights run normally. Horn works, All of the lights work properly except the indicators.

That's not a closer inspection, rip the damn clutch side cover off :bleh:

[Haggis2]

Even if you can't fix it don't just dump it - put it on trademe and someone else will pick it up and (maybe) fix it. At least then you can recoup some of your $$$

[Oblivion]

That's not a closer inspection, rip the damn clutch side cover off :bleh:

I dont have the proper sockets to do it at home :lol: Thats tomorrows job. Maybe over a few beers. Who knows :rolleyes:

[Ender EnZed]

I have no idea what's wrong with it, but I'd recommend setting it on fire and pushing it off a cliff.

[FJRider]

414$ Worth :doh:

There is the "Quit while you're only $414 (refundable if you deregister) behind option ...



Well, Upon closer inspection, the flash unit is buggered, since the indicators are solid. But are there any other signs of an electrical failure that I should look for? Because the headlights run normally. Horn works, All of the lights work properly except the indicators.

Indicators "solid" ... I assume you mean come on but dont flash. This can be caused by a bad earth to the bulb(s).

Not so silly question ... but have you looked at (IN) the fuse box ... ???

Look for blackened wiring around (electrical) bits that dont work.

[ktm84mxc]

There are a few easy tests you can do first- try removing the spark plug if you can't chances are its dropped a valve, remove the cam chain adjuster and see if it hasn't broken the chain jamming the bottom end, drain the oil and check with a magnet for metal bits jamming the clutch\gear box, remove the tank to check for electrical shorts the coil and stator will need testing by an auto electrician.
The humble GN has been on the NZ market for almost 30 yrs so 2nd parts are easily sourced.

[Oblivion]

There are a few easy tests you can do first- try removing the spark plug if you can't chances are its dropped a valve, remove the cam chain adjuster and see if it hasn't broken the chain jamming the bottom end, drain the oil and check with a magnet for metal bits jamming the clutch\gear box, remove the tank to check for electrical shorts the coil and stator will need testing by an auto electrician.
The humble GN has been on the NZ market for almost 30 yrs so 2nd parts are easily sourced.

Parts are easily interchangeble with bikes like the GN, so if I can get all of the stuff together, I'm sure I can fix it. No promises though :sweatdrop


There is the "Quit while you're only $414 (refundable if you deregister) behind option ...




Indicators "solid" ... I assume you mean come on but dont flash. This can be caused by a bad earth to the bulb(s).

Not so silly question ... but have you looked at (IN) the fuse box ... ???

Look for blackened wiring around (electrical) bits that dont work.

Have done that, Nothing new that wasn't there before. Checked all of the wiring that I could find, and most of the blackening that is there is just excess grease. <_<

If I can get a socket set somewhere tomorrow, Ill be taking the top end off and taking a looksie.

[Oblivion]

Apparently its not as bad as first thought. The start clutch has pretty much destroyed itself. The bolt was broken in half, and the metal contorted around the inside of the bike. A lot of metal shavings everywhere. The Alternator housing was intact, which was a bonus. Cleaning out the metal shavings is for tomorrow, but hopefully we can find another starter clutch and some bolts for the alternator housing. There was metal putty inside the casing, which we found strange. Looks like someone has been in there and done some repair work before.

If I could find my camera, I would upload some pics, but someone had stuffed off with all of teh SD cards for the cameras.