Help..... Blown head gasket?

Ok first things first, i have a 99 sv650s (curvy). Mods are all cosmetic i.e, indicators and screen apart from a fuel aftermarket exhaust (exhaust fitted 1 week prior to engine going bang and carbs were yet to be calibrated for the can).

My bike endures a lot of miles a month (140mile round trip to work) and had started to notice a loss of power on the motorways, struggling to get past 80mph then suddenly all was well again, I gave the bike a service (new plugs, oil, oil filter and air filter) and it seemed ok for a while. I then noticed an unusual nocking from the engine on idle and sometimes whilst riding along with the loss of power again, she was also using more oil than usual. Then whilst riding home i heard a loud bang come from the engine and a huge loss of power, i pulled over and there was a loud banging/grinding noise and smoke coming from the rear cylinder! I have searched these symptoms on the org and have come to the conclusion that its probably a head gasket.
Can anyone confirm that this is the case or any other possibilities?????
Also does anyone have any idea on a price to get her up and running again? She was my first big bike and desperatly want to get her sorted!

Thanks for reading guys n gals, hope to hear ur suggestions soon

hi wezza

can you answer a few quick questions to give me a better idea of the problem.

what colour was the smoke?

and does the sound seem to come from the top or bottom of the engine ?

all the best

MJP

[Dave20046]

Can you see any oil leaking from the rear cylinder? If it's the head gasket it'll be damp round the mid section ish of the rear cylinder. If it is then you need to investigate further.

You need to check your cooling system I'd drain, flush and refil it and check the radiator for leaks. Also leave it on tick over occasionally revving for 5-10minutes (probably not advisable, but once shouldn't hurt unless someone has a cleverer way) to check your fan works.

sounds more like symptoms of blown bottom end bearings on one cyclinder?

[fizzwheel]

Originally Posted by 454697819

sounds more like symptoms of blown bottom end bearings on one cyclinder?

Thas what I was thinking. Loud bang accompanied by grinding / knocking and loss of power. I think thats probably more terminal than just a head gasket. But its hard to diagnose these things over the internet when you can't see or hear the bike.

[Dave20046]

Originally Posted by 454697819

sounds more like symptoms of blown bottom end bearings on one cyclinder?

nooooooooo
That sound baad

[Dave20046]

Originally Posted by fizzwheel

Thas what I was thinking. Loud bang accompanied by grinding / knocking and loss of power. I think thats probably more terminal than just a head gasket. But its hard to diagnose these things over the internet when you can't see or hear the bike.

I did wonder about the grinding, thought it might have seized a bit or something.

yep... if it is that it is usually terminal...140 miles a day thats circa 35k a year...

as a 99 bike could have 60k plus...?

[Dave20046]

Originally Posted by 454697819

yep... if it is that it is usually terminal...140 miles a day thats circa 35k a year...

as a 99 bike could have 60k plus...?

The clock on my 99 is only showing £7k... I'm a bit suspicious lol.

no no... you do get genuine low mileage bikes however with a 10 year old bike with an average of 4k a year plus this guys 140 a day, it wont take long to get to the 60k...

other bits should tell you if its done 7 k or not..