Seized engine?

[Deviant]

Hey guys, looking for some advice here.

About a week and a half back, I pulled up outside a veggie shop after a long ride (rush hour, Northcote to Mt Roskill), bought some veggies, and went to ride off.

Only I couldn't, because the engine had seized up.

Here's the syptoms:

Suzuki GN250

Electrical ignition- when starting it tries to start, but something locks up before it makes it's first "turn" of the engine. It's only getting a tiny bit of the way through before it locks.

Tried a rolling start, putting it in gear locks the back wheel.
Removing and cleaning the spark plug didn't help- it's getting power anyway so I doubt that's it.

It was low on oil, but the engine was hot and topping it up didn't help.

The back wheel and chain move freely in neutral, only locks in gear when the clutch is off.


Any ideas what it could be, and whether I can fix it myself (having no mechanical history) or need to fork out for a store fix?

I'm off this weekend so I'm thinking of getting it done Saturday if I can't fix it myself.

Thanks in advance for any input.

[xwhatsit]

Those symptoms could be down to the starter shitting itself (is this the sort of failure where you hit the starter with a hammer and it engages or summat?). The rear wheel locking when you try to bump start; have you bump started a single before? The GN250 is not particularly high-compression, but I'd still hazard a guess that it'll lock the wheel unless you first roll it back against TDC. Put it in first gear, then pull the bike backwards, the engine should whirl and chuff backwards until it will just stop; now you're at compression; when you drop the clutch, the bike will go through a full cycle before coming up against TDC again, so you'll get some momentum and compressed charge and the wheel won't lock.

Also, when you drop the clutch, time it perfectly and slam your arse down on the seat.

I wouldn't think that an engine would seize after leaving it, long ride/hot engine or not. Surely it would only seize while it was still running.

If you really want to determine whether it's seized or not, pull out the spark plug again, then try rolling the bike in 2nd gear. It should turn over, without the spark plug there won't be any compression. If it still won't turn, then you've got issues.

[Ixion]

Your battery is flat , becos your charging circuit is stuffed.

Maybe.

[Forest]

Definitely sounds like a flat battery.

[Deviant]

Hi Ixion, I checked the battery. While it's nearly flat now (left the headlight on while trying to fix it then went out for half an hour), it wasn't at the time. But it certainly could be battery related. It just doesn't feel like that at all- something inside the engine cover is stopping it from turning over.

The guy I called at Holeshot suggested the battery, a lot of people have, because it shouldn't seize up just sitting there, but it also shouldn't go from running hot and fine to a flat battery while turned off in a couple of minutes. It's just weird how it happened.

xwhatsit, I'll give that a shot but my mate from work already tried something like that. I don't think it can be forced, something is actually locking it tight. The wheel just wont turn if it's in gear with the clutch off. But I'll give it a shot tomorrow anyway, it's got to be better than doing nothing.

Thanks for the inputs though, it's all helpful.

[howdamnhard]

Put your battery on overnight charge.As xwhatsit said remove the plug put it in 2nd and try turn motor over,should turn with no compresion.When my regulator/rectifier blew it took out the fuse and it was pretty sudden.Refit charged battery and bump start as xwhatsit said but hit starter as you drop clutch,might be just enough to get it going.Do a search for a workshopmanual on the forums.

[Forest]

The guy I called at Holeshot suggested the battery, a lot of people have, because it shouldn't seize up just sitting there, but it also shouldn't go from running hot and fine to a flat battery while turned off in a couple of minutes. It's just weird how it happened.

If your charging circuit is dead, the engine will run using energy from the battery.

As a consequence the battery may be flat when you attempt to restart the engine.

[bobsmith]

Yeah, I'm the guy who tried to see what's wrong with his bike...

Really strange since even after I removed the spark plug, we couldn't get the engine turned over at all...

Someone mentioned a fucked started. If a starter is fucked and not releasing from the engine could that lock the engine hard enough that we can't get it turning over?

[Deviant]

I'm 99% certain its mechanical, not electrical.

There is heaps of power, it fires, tries to turn, then locks.

The wheel is locked.

It's something in the engine or starter motor I reckon, can't get the engine cover off to look at it, broke a ratchet trying.

[The Stranger:Me]

Hey guys, looking for some advice here.

About a week and a half back, I pulled up outside a veggie shop after a long ride (rush hour, Northcote to Mt Roskill), bought some veggies, and went to ride off.

WTF!
We didn't spend the last million years climbing to the top of the food chain to eat that shit.

Best advice - leave it for the rabbits.

[The Pastor]

I think i know what the problem is.

A long ride isnt north cote to mt roskill!!!!

[kevfromcoro]

I'm 99% certain its mechanical, not electrical.

There is heaps of power, it fires, tries to turn, then locks.

The wheel is locked.

It's something in the engine or starter motor I reckon, can't get the engine cover off to look at it, broke a ratchet trying.

Bit lost here....it fires?? so the motor is turning over....
The wheel is locked??? are you trying to start it in gear....
As sugested..take the plug out...put it 2nd.and push it..
if all if free.and turns your motor aint seized..

[barty5]

Bit lost here....it fires?? so the motor is turning over....
The wheel is locked??? are you trying to start it in gear....
As sugested..take the plug out...put it 2nd.and push it..
if all if free.and turns your motor aint seized..

dose sound strange but im sure 2 people wouldnt make the same mistake while lookin at it almost sound like somthing towards the gearbox if its trying to turn over then locks up (starting to urn then conects with what ever has ben damaged) i would drain the oil to start with and filters see what foreign item comes out with the oil.

[awayatc]

be tempted to blame seized starter, however, other bits may have broken/seized and prevent engine turning....
You will have to break out some tools and start taking off some engine covers....
Amazing what you may find...Or eliminate...
Good luck

[kevfromcoro]

dose sound strange but im sure 2 people wouldnt make the same mistake while lookin at it almost sound like somthing towards the gearbox if its trying to turn over then locks up (starting to urn then conects with what ever has ben damaged) i would drain the oil to start with and filters see what foreign item comes out with the oil.

Got me straching my head......though about the gearbox too......
thought pushing it in neutral would elimate that...
Havent left your rear disc lock on have ya??