ZZR250 overheated, blew head gasket

[imthatguy]

Sup guys, First post!

So yesterday I was heading up to Taupo from Palmy, my bike overheated and is now acting like an expensive piece of scrap metal.

Heres the story; It was around Taihape area when I first noticed it was down of power, but as it was nearly out of fuel I switched it over to reserve and thought nothing more of it (that may or may not be related).

About 100m out of Wairuru the bike began to smell really hot and developed what sounded like a knock so I pulled over into the Z station as I had to get some fuel anyway, just as I pulled up next to the pump, the bike stalled.

To my horror I discovered the last dregs of my coolant spewing out everywhere from the water pump area, I soon realised this was because the bolt that holds the inlet pipe into the water pump, had somehow worked itself lose and the inlet pipe had been happily pumping coolant onto the ground!

I went inside and secured some tools which I used to reattach the pipe with another bolt I temporally pillaged, then I tool the faring off over the radiator cap and proceeded to pore cold water into the radiator - probably shouldn't have done that as next thing I know theres an enormous cloud of steam and more coolant on the ground! On closer inspection I discovered this was coming from the front of the engine just under the exhaust headers.. Oh dear.

It won't start now (bit of a given really..) and while the radiator cap was off I noticed that when the engine was turning over it was bubbling the coolant which isn't a good sign.

Sooo anyone have a rough idea what Im up for a new head gasket?
Also what do you think the knocking noise would have been?

Cheers guys,
Aaron

[tri boy]

If you noticed it was down on power a while back, (even a minute or two) and kept riding, then budget on a topend rebuild. ie rebore, pistons/rings/gudgeon etc, plus probably valve/seat damage etc.
Strip an inspect.
It probably won't be cheap

[imthatguy]

If you noticed it was down on power a while back, (even a minute or two) and kept riding, then budget on a topend rebuild. ie rebore, pistons/rings/gudgeon etc, plus probably valve/seat damage etc.
Strip an inspect.
It probably won't be cheap

Well to be honest Im not sure it was that I could feel, as I said it was genuinely low on gas, and it seemed to correct itself after I switched to res..

Would something in the top end cause the knock?

As it happens I actually have another motor sitting in my garage I took out of this bike ~3 months ago for an unrelated issue, so hopefully I can pillage some parts off that. Otherwise another engine isn't really the end of the world..

[tri boy]

Spare engine might just save you a bucket load of dosh.
Strip an check anyhow.
If your knowledge in such areas is limited then seek help. A "can do" effort could cost. mho.

[imthatguy]

Spare engine might just save you a bucket load of dosh.
Strip an check anyhow.
If your knowledge in such areas is limited then seek help. A "can do" effort could cost. mho.

Unfortunately I don't know anyone else who can help, but Im confident I can work it out.

I bought this bike as a project to learn about/on, would be nice to be able to actually use it at some point though..

I have exams right now, so it will have to wait - Ill strip and inspect after and report back.

Thanks for your help!

[mossy1200]

http://www.trademe.co.nz/motors/moto...-797286650.htm

[imthatguy]

http://www.trademe.co.nz/motors/moto...-797286650.htm

Are you insinuating??

I decided this is much more interesting then study, so I've got most of the head off, will let you guys know what I find.

[mossy1200]

Are you insinuating??

I decided this is much more interesting then study, so I've got most of the head off, will let you guys know what I find.

Hope you have a good eyeometer

[ducatilover]

I may be in Palmy area at some stage in the near future, I'd be happy to lend a hand

If it's properly cooked, like you describe, I would be avoiding using the engine at all. Chances are it's got hot enough to fuck the oil, and in turn the bearings, rings, etc.
Why did you take your other motor out?

[imthatguy]

I may be in Palmy area at some stage in the near future, I'd be happy to lend a hand

If it's properly cooked, like you describe, I would be avoiding using the engine at all. Chances are it's got hot enough to fuck the oil, and in turn the bearings, rings, etc.
Why did you take your other motor out?

Hey thanks man! I appreciate that. Let me know when your down, Ive also got a fzr250 that needs the carbs cleaned if your interested?

Understood, as I mentioned before it won't even start so no chance of that
And its now in multiple pieces on my garage floor - had to get some work do so I've abandoned it for now, but Ill assess the damage tomorrow and decide on the way forward.

To be clear, I don't think it seized, exactly, I think because the head gasket went it just lost compression, thats what It FELT like anyway, time will tell I guess.

Well actually, I took it out because I thought it had also overheated haha (motorcycle noob as you can tell), though on closer inspection I failed to find much evidence to support my theory. The motor thats in there atm is much newer though, so if possible it would be nice to salvage it, if possible.

The original engine one would run fine until you hit 100kmh, then almost instantly you would lose power, it would start blowing clouds of white smoke, and it would very quickly seize and be un-turnoverable for 40-50minutes until it has sufficiently cooled down.

[The Reibz]

Chances are you have warped the cylinder head. Pouring cold water into it while its still massively hot may have also caused it to crack.
Buy the 2nd hand engine mossy posted.

[imthatguy]

Chances are you have warped the cylinder head. Pouring cold water into it while its still massively hot may have also caused it to crack.
Buy the 2nd hand engine mossy posted.

Fair enough, Im about to find out. What would be a telltale sign that the head is warped? I assure its more or less the same as a car engine?

Im not in a huge hurry to get this back on the road so will probably shop around until I find one for cheaper then that. The engine I have in there now I picked up for $300 with 30k on it and a months warranty..

[The Reibz]

Run a straight edge over it. If it's warped you will know

[bogan]

I'm in palmy, can provide second opinion as needed. Got a bunch of measury things (technical term) lying about that I can throw at it...

[mossy1200]

Fair enough, Im about to find out. What would be a telltale sign that the head is warped? I assure its more or less the same as a car engine?

Im not in a huge hurry to get this back on the road so will probably shop around until I find one for cheaper then that. The engine I have in there now I picked up for $300 with 30k on it and a months warranty..

I didnt mean any disrespect but if it was me idd chuck the second hand motor in and then rebuild yours as a project as you have spare money. Full rebuild, not just a temp repair or keep the spare bits as they will serve you in the future.
Its most likely from your op that you have a warped head so that will need skimmed and crack tested. Maybe new pistons and a oversized bore, bottom end rebuild new cam chain and sprockets if you want the best repair. The question is if you start a rebuild are you going to get your monies worth or are you going to upgrade to a larger bike in the near future. Your rebuilt motor wont fetch you a lot more if any when you sell or trade your bike. in fact idd say idd say running bike with spare motor as parts be worth the same amount in your pocket.