Starting issues, compression... '85 GSX550

[Stelmer]

I know I need to get a compression tester but I thought i'd ask for advice first.

Just spent around an hour starting the GSX for the first time in 14 days.

It sounds like it's loosing compression on a cylinder as it makes an odd noise when cranking. Like the normal starting noise with a short, regular speed up then back to the normal noise.

Once it fired, it ran ok with no smoke from the exhaust but weak blue smoke from the breather hoses.

I let it warm up and from hot, it is a little hesitant on firing up but cranks somewhat normal. I've now turned it off and letting it cool before trying it again.


Any ideas?

Hopefully it's not the rings but it could be the head gasket or valves.

[Pete.]

The GSX550 did have a habit of burning up the valves on high mileages. You might as well do a compression test.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Stelmer]

Yeah, mileage is somewhat unknown so best get a compression tester.

Also, i could've flooded it...

[baldy]

The blue smoke idicates that it's burning oil. It could just need a rebore and the valves lapping in.
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One day i will rule the world, just not today.

[Stelmer]

It's the valves, or is likley the valves.

Earlier it sounded very odd and smoked like crazy.

Cleaned plugs (2 covered in oil) and it fired up easy and had compression. Bit of smoke and a misfire.

Time for an engine strip I think.