Oh dear GT550 Engine not sounding good

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Harrymail
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Re: Oh dear GT550 Engine not sounding good

Post by Harrymail »

Well that's my engine and carbs dropped off at Baz's house for rebuild. Great to meet Baz and made very welcome with my two mates who humped the engine in and out of the van.

Nice cup of tea too :)

Paul (Harry)
Last edited by Harrymail on Sat Aug 25, 2018 12:32 am, edited 1 time in total.
Currently without a GT, but looking
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BAZ
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Re: Oh dear GT550 Engine not sounding good

Post by BAZ »

Off to the IOM, tomorrow will strip engine when I get back and post pictures, great to meet up and thanks for the work. cheers Barry
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BAZ
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Re: Oh dear GT550 Engine not sounding good

Post by BAZ »

Ok stripped engine see pictures give me a buzz tonight sorry pictures in wrong order.

https://vimeo.com/288768948 video clip
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PaulD738
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Re: Oh dear GT550 Engine not sounding good

Post by PaulD738 »

That’s a cracking guide for anyone stripping their motor Baz 8-) looks like new pistons & a rebore are required :roll:
They're rubbish them Jap bikes lad they won't last five minutes! you want to get yourself a nice Royal Enfield!
A quote from my old dad 8-)

I started out with nothing and I’ve got most of it left!
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BAZ
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Re: Oh dear GT550 Engine not sounding good

Post by BAZ »

See clip of crank.
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Harrymail
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Re: Oh dear GT550 Engine not sounding good

Post by Harrymail »

BAZ wrote:Ok stripped engine see pictures give me a buzz tonight sorry pictures in wrong order.

Thanks Baz, a bit of work to do then. The video says it all. And it was running real well till it started rattling 2 weeks ago. Will ring you ,

Cheers

Paul
Currently without a GT, but looking
2003 Yamaha Fazer 600 Blue
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barney01
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Re: Oh dear GT550 Engine not sounding good

Post by barney01 »

So what's the verdict chaps? For the uninitiated does that big end bearing play mean it's failed and caused the cylinder problem?
Or was it oil starvation?
NO SMOKE .......NO POKE
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PaulD738
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Re: Oh dear GT550 Engine not sounding good

Post by PaulD738 »

BAZ wrote:See clip of crank.
Yes there is a “tiny” amount of play there :roll:
They're rubbish them Jap bikes lad they won't last five minutes! you want to get yourself a nice Royal Enfield!
A quote from my old dad 8-)

I started out with nothing and I’ve got most of it left!
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Harrymail
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Re: Oh dear GT550 Engine not sounding good

Post by Harrymail »

barney01 wrote:So what's the verdict chaps? For the uninitiated does that big end bearing play mean it's failed and caused the cylinder problem?
Or was it oil starvation?
I am keen to know the verdict myself Barney. Its not had oil starvation recently to my knowleage. It certainly uses 2 stroke oil. The LH bore did have some fragments of metal in it, as yet not identified where they have come from. Baz thought there may have been oil starvation at some time. Could be before I owned the bike, though I have had it for 10 years.

I spoke last week to the first owner of the bike, who bought it from new. When it was 13 months old the engine "blew up", at 5,000 miles. It had a rebuild with an exchange crank from Crooks Suzuki and a new middle barrel and piston. That was 40 years and 20,000 miles ago. The engine has not been touched since. So maybe it is just "worn out" ?

Paul (Harry)
Currently without a GT, but looking
2003 Yamaha Fazer 600 Blue
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barney01
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Re: Oh dear GT550 Engine not sounding good

Post by barney01 »

Thanks Harry. I have had 2 catastrophic seizures in my bike which I have owned for 25 years. Both in the early days before I understood these engines. You did the right thing in recognising the rattle was serious and getting a lift home. I tried to limp home and the left piston seized mid bore and the conrod ripped the bottom of the piston out and it punctured the crank seals on the first one. It was caused by oil starvation. I think a blocked oil feed banjo. The second was a timing drift effectively overheated right spark plug so much it melted a hole in the piston crown. (This is why I now have Newtronic ignition) as I switched the bike off there was that awful sounding click as it seized. That was 20.000 miles ago and touch wood no problems since. Good luck with your rebuild it's cartainly in good hands with Baz.
NO SMOKE .......NO POKE
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