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]

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??

[The Stranger]

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.


A dropped valve would do that.

[MaxB]

Got me stumped. A while back there were a few problems common to the Chinese made GNs based around assembly and clearances but blowed if I can remember.

My gut feeling, if everything is as they said, is starter motor or gearbox, something loose or disengaged.

[Pedrostt500]

I geuss it might be time to drop it in to your local bike shop, ask them for a diagnosis, and a quote to fix.

[ManDownUnder]

Sorry - it's still not clear (from what I've read)

Put it top gear, clutch in and push it - ease the clutch out - does the motor turn over? If so - not seized.

If it turns part of the way then suddenly STOPS it sounds like a dropped valve or something mechanical actually stopping things (try going backwards at the point see if the motor moves a bit then stops again...?). At that point - don't force anything... you'll only damage valve, piston and cylinder head

I'd put money on a dropped valve if pressed but it's not enough evidence. Taking the rocket cover off would prove it... 1 valve missing?

First things first - sprak plug out, a few drops of 2 stroke oil in the hole. If it is partially seizing that might helpd keep things apart long enough to dismantle it. Then it's buy a head gasket kit, head off - and take a looksee.

[xwhatsit]

A dropped valve would do that.
Yeah, but... would it drop a valve while turned off? He rode it quite happily, parked it, then came out a little later and went to start it. It drops a valve when he hits the starter?

Seems bizarre.

Do try and roll it in 2nd gear (or top) with the spark plug out. Or yes, take off the tappet inspection covers and have a nosy.

[The Stranger]

start it. It drops a valve when he hits the starter?

Seems bizarre.


That it does.
That said R6_Kids GSXR did exactly that when we hit the starter.

[bobsmith]

Do try and roll it in 2nd gear (or top) with the spark plug out. Or yes, take off the tappet inspection covers and have a nosy.

First thing I tried when I got there....

It rolls find when I have it in gear with the clutch in but as soon as I let the clutch out the frekking engine won't turn (even with the spark plug off)

I'm going to go over there today with my tools and open the top end off the engine and see if we can see anything and if nothing's obvious will take some pictures of the inside and post it here. Perhaps someone can shed some light from the pictures.

[paturoa]

Try putting it in top gear and gently roll it backwards. If it is a jammed starter then that may unlock it.

Also before taking the head off, take out the starter motor and have a butchers around there. Eliminate the easier stuff before pulling it apart.

[Deviant]

It can't be turned in any gear, removing the spark plug has no effect on anything.

We didn't get around too looking at it because I got smashed last night and spent all day watching sci-fi TV series' in bed.

Perhaps tomorrow if we have time.

I'm thinking its what a couple of you said, dropped valve or cracked piston?

Thinking that as it cooled down after being heated up, something may have cracked. Expanding/contracting metal and all that.

My comment about the 'long ride' was to indicate the engine had heated up. It wasn't just a 2 minute trip up the road.

A truly long ride would be another trip up to Paihia taking the scenic routes or down south somewhere (Vegas). :)

Bring on summer!

[Deviant]

Got the bike back, it turns out a bolt had shorn off the cluthc (?) and gone through the engine ripping the shit out of everything it could, then the engine just cacked it. Took it to Chris at Queen Street Motorcycles in town who has replaced it with a Japanese made engine (old one), which seems to be running fine (just rode it to work on the shore).

It took a long time because of the Xmas break, lack of fund, car crash, unexpected $1300 bill that had to be paid immediately and other things.

Now I need to work on getting the car fixed before the winter storms because I wont be risking my life daily over that bridge on a flimsy little GN250 like I did all last year! I swear, the number of times I nearly ended up greasing some trucker's axles with my own body fat due to gusts coming down the Auckland side of that f***ing bridge!!!

Good to be on two wheels again though :D

[peasea]

Got the bike back, it turns out a bolt had shorn off the cluthc (?) and gone through the engine ripping the shit out of everything it could, then the engine just cacked it. Took it to Chris at Queen Street Motorcycles in town who has replaced it with a Japanese made engine (old one), which seems to be running fine (just rode it to work on the shore).

It took a long time because of the Xmas break, lack of fund, car crash, unexpected $1300 bill that had to be paid immediately and other things.

Now I need to work on getting the car fixed before the winter storms because I wont be risking my life daily over that bridge on a flimsy little GN250 like I did all last year! I swear, the number of times I nearly ended up greasing some trucker's axles with my own body fat due to gusts coming down the Auckland side of that f***ing bridge!!!

Good to be on two wheels again though :D

You lead an interesting life, don't you?

[klingon]

Got the bike back, it turns out a bolt had shorn off the clutch and gone through the engine ripping the shit out of everything it could, then the engine just cacked it. ...

That's zakly what happened to my Volty. (All fixed now too... I needed a new engine anyway) Hooray for you being back on two wheels! :wari:

[The Stranger]

That's zakly what happened to my Volty. (All fixed now too... I needed a new engine anyway) Hooray for you being back on two wheels! :wari:

You get that with those high torque engines.

[Deviant]

Well it's been over a month now, and asides from a few loose bolts, I have to say Chris did a good job on the bike!

It's running as good if not better than ever before, and after a bit of wearing in and some general maintenance (helped out by pyrocam) the bike is in good shape.

We bled and replaced the front brake fluid, loosened the front brake, tightened the clutch and back brake, tightened and oiled the chain, tightened a few loose nuts, and some other stuff.

It's like riding a different machine!

[Conquiztador]

It's like riding a different machine!

It is! You have a different engine!

S/H working GN engines should not cost you more then $200 - $400. (Said that, I know someone who paid $800 for one apperently mint...yeah right!)

[vindy500]

whats with such new bikes arsing over