Got some time on my hands as the weather changes for the better and trying to get a few lingering projects knocked off the list for my bike.
First off is a leaky clutch rod seal. Apparently a pretty common issue and a nice cheap part but I'm having trouble figuring out whether the seal installs from the outside or the inside. Based on what I can see from the outside it looks like it installs from the inside which would require splitting the case, but there is an external retainer assembly that bolts from the outside. Apparently Suzuki has used both designs before so if anyone can give me a definitive answer for the 1978 GS400 that would be great. If I have to split the cases this project is getting put right back on the back burner because there's no way I'm pulling the engine out at the beginning of the riding season or it'll be November before I i get it back in. If it's a quick matter of prying the old out out and driving the new one in, I'll get it done.
Next up is what I have narrowed down to almost certainly being a loud cam chain. It's a noticeable medium pitched growling coming from the top end and it seems to really concentrate around the cam chain area. If i stick a screwdriver to the top of the cam cover where the chain idler is it seems the loudest. Obviously whatever it is (even if it's just normal noise, i know these things aren't exactly quiet) would require me to get the cam cover off to inspect anyway but I'm hoping to get some "most likely culprits" before i go poking around in there. My tensioner is set right and works properly when testing it using the method in the manual. It does seem to have a bad seal because i get a nice bit of grease on my fingers anytime i touch it and I have seen solitary drops of oil hanging from it before but there's never any pooling or any noticeable leaks so I can't imagine that's affecting much, though i do plan to replace that o-ring at some point since it appears to be the only internal seal on the assembly
For context the bike only has about 12,800 miles on it so I'm assuming the odds of a worn cam chain are pretty low. Valves and clearances are good, seats were recently lapped and it got brand new intake valves all less than 500 miles ago but this sound has been here since I got the bike so I'm starting to think it's just the way it is.
Here's a video of a cold start: https://youtu.be/BYHMtA8FsT8 . I have also noticed a slight hissing? sound for the first few seconds when the bike is running cold, which goes away after it runs for a few seconds, almost as if there is a small leak that is sealing itself as the bike heats up. You may be able to hear it in this video. If anyone has insight on that I'd love to hear it too. The bike did have some vertical scoring on the cylinders when I got it from locked rings but I was able to get 90% of it out with a ball hone and put a new set of rings on it. Could it just be a small amount of extra clearance on the cylinder walls that goes away as the rings expand? If so I assume the only fix would be to fully repair/sleeve the cylinders.
Thanks guys, still loving the bike just don't want to see it blow up on me. I'd never forgive myself.
First off is a leaky clutch rod seal. Apparently a pretty common issue and a nice cheap part but I'm having trouble figuring out whether the seal installs from the outside or the inside. Based on what I can see from the outside it looks like it installs from the inside which would require splitting the case, but there is an external retainer assembly that bolts from the outside. Apparently Suzuki has used both designs before so if anyone can give me a definitive answer for the 1978 GS400 that would be great. If I have to split the cases this project is getting put right back on the back burner because there's no way I'm pulling the engine out at the beginning of the riding season or it'll be November before I i get it back in. If it's a quick matter of prying the old out out and driving the new one in, I'll get it done.
Next up is what I have narrowed down to almost certainly being a loud cam chain. It's a noticeable medium pitched growling coming from the top end and it seems to really concentrate around the cam chain area. If i stick a screwdriver to the top of the cam cover where the chain idler is it seems the loudest. Obviously whatever it is (even if it's just normal noise, i know these things aren't exactly quiet) would require me to get the cam cover off to inspect anyway but I'm hoping to get some "most likely culprits" before i go poking around in there. My tensioner is set right and works properly when testing it using the method in the manual. It does seem to have a bad seal because i get a nice bit of grease on my fingers anytime i touch it and I have seen solitary drops of oil hanging from it before but there's never any pooling or any noticeable leaks so I can't imagine that's affecting much, though i do plan to replace that o-ring at some point since it appears to be the only internal seal on the assembly
For context the bike only has about 12,800 miles on it so I'm assuming the odds of a worn cam chain are pretty low. Valves and clearances are good, seats were recently lapped and it got brand new intake valves all less than 500 miles ago but this sound has been here since I got the bike so I'm starting to think it's just the way it is.
Here's a video of a cold start: https://youtu.be/BYHMtA8FsT8 . I have also noticed a slight hissing? sound for the first few seconds when the bike is running cold, which goes away after it runs for a few seconds, almost as if there is a small leak that is sealing itself as the bike heats up. You may be able to hear it in this video. If anyone has insight on that I'd love to hear it too. The bike did have some vertical scoring on the cylinders when I got it from locked rings but I was able to get 90% of it out with a ball hone and put a new set of rings on it. Could it just be a small amount of extra clearance on the cylinder walls that goes away as the rings expand? If so I assume the only fix would be to fully repair/sleeve the cylinders.
Thanks guys, still loving the bike just don't want to see it blow up on me. I'd never forgive myself.
