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14-01-2010, 10:19am
(This post was last modified: 14-01-2010, 10:20am by ross79.)
The busa has developed a bit of a smoking habbit lately. Intermittent. I'd start the bike in the morning to be greated by plenty of smoke. The next day it would start smoke free. It always stops smoking after a bit of riding.
Currently 60k on the clock (2003 model).
I thought it might be valve stem seals. Pulled the engine out on the weekend, removed cams and spark plugs. Screwed a pipe into spark plug hole of cylinder 1 and clipped it to the air compressor. Pressurised it with the compressor to find air rushing out from the exhaust port from around the second exhaust valve. Tried the remaining cylinders and they were all fine. My guess is a burnt exhaust valve?
I'm trying to remove the head but can only fit 1/4 inch sockets onto the head bolts. These don't have the strength to loosen them. Has anyone taken the head off their busa? If so how did you undo the head bolts??
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long reach 3/8drive 12mm tube socket and a 3/8to 1/2 adaptor
not common to burn a valve, have a good look when the top is off and see if there is any other prob
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14-01-2010, 04:51pm
(This post was last modified: 14-01-2010, 04:52pm by Legend.)
Carbon build up will cause a valve not to seat properly, causing the air leak possibly there from the oil thats getting burnt.
Like Maj said uncommon for a valve to fail, and if it was, the bike would have bugger all hp.
Leonard.
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Thanks for info. My dad managed to source me a 1/2inch long socket that did the trick. Pulled the head off and both exhaust valves on 1st cylinder look unhappy. Badly carboned and burnt about a 1/3 of the way up the stem. Will clean carbon off and measure to see if it's still within specs.
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Make sure you find out what caused the carboned up valves, ie: worn guides, seals , rings etc etc before you put it back together.....or you'll be doing it again!
Leonard.
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Will do. Unfortunately I can't get away from work. Might have to leave it till weekend, but plan to compare all the valve springs as well as suss out seats, piston rings etc. It was a nightmare getting the thing out of the frame especially when doing it alone. So I don't plan to repeat the process any time soon.
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Did you manage to check your cam clearances before pulling the engine down? Not tight were they?
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Cleaned up the valves but looks like they are a bit burnt. Showing signs of pitting on the lip so I'll be replacing them. Checked piston rings and all looks fine there (will be chucking in a new set to be on the safe side). Will be chucking in new valve springs too.
Are the bores lined with something on these bikes? I have over 60k on the clock and the cross hatching is still pretty clear on the bores.
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Thanks camel. That's exactly what I was looking for. Now I just need to buy the honing stones. Great writeup!
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Don't need to do much on the niccasil cyls, very light hone with the proper diamond hone or nothing
bet if you checked your ring gaps they would still be in spec
also many i have dissasembled had not yet worn across the face of the ring , you will see the wear only about 1/2-3/4 down
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With the motor out of the frame
