Oh dear GT550 Engine not sounding good

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barney01
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Joined: Wed Sep 26, 2012 7:33 pm
Location: Prestatyn.Wales

Re: Oh dear GT550 Engine not sounding good

Postby barney01 » Tue Sep 10, 2019 8:58 pm

Paul it certainly looks like your cylinder mixture was contaminated with gearbox oil. The reason your left cylinder had some as well is because the right SRIS would have fed some of the same into the left cylinder and that accounts for the middle being unscathed
NO SMOKE .......NO POKE

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Harrymail
Posts: 429
Joined: Thu Jul 07, 2016 8:35 pm
Location: East Yorkshire

Re: Oh dear GT550 Engine not sounding good

Postby Harrymail » Tue Sep 10, 2019 10:33 pm

barney01 wrote:Paul it certainly looks like your cylinder mixture was contaminated with gearbox oil. The reason your left cylinder had some as well is because the right SRIS would have fed some of the same into the left cylinder and that accounts for the middle being unscathed


Thanks Barney, that's good info. I didn't know how the SRIS works. I now understand how the oil can get to the LH cylinder. I expect when I drop the oil it will have petrol in it.

Paul
1977 GT550A Black
2002 Fazer 600 Silver
1968 BSA Bantam Red

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Harrymail
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Joined: Thu Jul 07, 2016 8:35 pm
Location: East Yorkshire

Re: Oh dear GT550 Engine not sounding good

Postby Harrymail » Wed Sep 11, 2019 9:18 am

Alan H wrote:Well, my 550A crank has just got back to Baz after a rebuild, so I hope the seals weren't out of your batch........ :roll:


I'm really surprised that this has happened Alan. Not what you would expect with a £500 crank rebuild. The crank was fine before the engine rebuild, but on strip down there was play on the conrods, hence having it rebuilt.
1977 GT550A Black
2002 Fazer 600 Silver
1968 BSA Bantam Red

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Alan H
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Joined: Fri Aug 05, 2011 6:38 am
Location: Wombwell, Republic of South Yorkshire

Re: Oh dear GT550 Engine not sounding good

Postby Alan H » Wed Sep 11, 2019 10:26 am

I think everything on my engine was 'tired'. Crank seals, bearings, gearbox bearings etc. I know it had some tatie while I had it, but as it wasn't a standard motor when I had a look inside during the resto, I don't know how it had been treated prior to getting the bike. Have a look on the 'Earwig' thread, which will be updated when there's progress 'soon'! :roll:
Proof that four strokes are over complicated


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