Nathan.Lasovich
New Member
New to the forum guys, but I've heard that this is THE cafe racer forum to end all forums. I picked up my first bike this year, a 1981 Yamaha XS400. I've gotten a lot done in regards to the body of the bike turning it into a cafe, but I've still been having a lot of trouble getting it running. I am very new to all things motorcycle-mechanics related though, so I may very well be missing something.
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[/size]First I replaced the battery, and the bike does have a good spark, so electrical must be good I assume. Unless of course, like I said, there's more to it than having good spark.
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[/size]After knowing that the bike had good spark, and still not starting, I pulled the carbs apart to make sure that after having been stored for a year before I bought it that it wasn't too filthy inside. They were relatively clean, but I did give them another once over with some carb cleaner and a toothbrush to get all the passages clear, and all the slides moving freely.
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[/size]Still not starting, I figured it might be a compression issue so I checked that and found that I've got one cylinder with about 150psi and one with only about 60. Bingo. Now, being as new as I am to fixing up a bike, I know that this is definitely an issue, but I'm wondering if it's actually the root of all my problems. Would one cylinder not having enough compression keep the bike from starting at all? Also, how do I begin with fixing this issue...I know it means I've likely got some bad valve seals and stuff like that, but is that an easy enough fix? How much tearing down of the engine is it going to take to fix? Something an amateur like myself should be able to pull off or am I better off taking it to a shop? All advice is greatly appreciated...
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[/size]Thanks!
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[/size]Nathan
[/size]
[/size]First I replaced the battery, and the bike does have a good spark, so electrical must be good I assume. Unless of course, like I said, there's more to it than having good spark.
[/size]
[/size]After knowing that the bike had good spark, and still not starting, I pulled the carbs apart to make sure that after having been stored for a year before I bought it that it wasn't too filthy inside. They were relatively clean, but I did give them another once over with some carb cleaner and a toothbrush to get all the passages clear, and all the slides moving freely.
[/size]
[/size]Still not starting, I figured it might be a compression issue so I checked that and found that I've got one cylinder with about 150psi and one with only about 60. Bingo. Now, being as new as I am to fixing up a bike, I know that this is definitely an issue, but I'm wondering if it's actually the root of all my problems. Would one cylinder not having enough compression keep the bike from starting at all? Also, how do I begin with fixing this issue...I know it means I've likely got some bad valve seals and stuff like that, but is that an easy enough fix? How much tearing down of the engine is it going to take to fix? Something an amateur like myself should be able to pull off or am I better off taking it to a shop? All advice is greatly appreciated...
[/size]
[/size]Thanks!
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[/size]Nathan
