So I picked up an '81 CB900c a few weeks ago because I'm jonesing to ride and I know my CB750 project will not be done this year. I got it for less than what it would have been worth in the condition this guy claimed it was in, knowing full well that that meant there's probably a lurking problem this guy knows about but isn't telling me. And of course, I found some. Any suggestions would be great.
Minor issues:
- Squealing brakes. This guy just replaced all the brake pads on the bike (two discs up front, one in the back) and they squeal at the slightest touch. The stopping power is great, so I'm kinda wondering where to start looking... The rotors have some surface rust but the calipers look great. I've never chased down an issue like this, so I could use some advice.
- Exhaust Rattle. The pipes are aftermarket. I figure they weren't installed correctly or there's something going on with the baffle inside. It only rattles at about 3000rpm.
- Leaky Carbs. No surprise here that a 30 year old Honda has a carb issue. There's no filter in the fuel line, and when I checked the tank I did see some gumming going on. The guy made a point of telling me that he always used premium, but that doesn't mean shit if you don't put stabilizer in the tank over winter. He had the carbs rebuilt two years ago (even gave me the receipt) but my guess is something just got up in there again. At the very least I'll have to clean out all the snot. I've done this twice before, so I know the drill.
Major Issues
- Stripped threads in valve cover bolt hole. This is the one I'm punching myself in the face for not checking. I knew there was an oil leak coming from the valve cover, but I didn't think to check the bolts. The guy had the valves set recently (again, another receipt), and I thought it was just a poor seat with the gasket. It would have been a deal breaker if I realized it was a stripped out bolt. At the very least, I would have asked for a much lower price. As it is, I walked away that day thinking I paid $500 less than it was worth, and now I think I overpaid. So what should I do here? Will a heli-coil work in this situation? The leak isn't horrendous. I lose about a teaspoon of oil per hour of hard riding I'd say. Probably less. Most of it ends up on my pants.
- Battery won't hold charge. One of the first questions you should ask when buying a DOHC honda from that era is "Are there any electrical problems?" With a straight face, this guy said "Nope. None at all." With the bike running, the system was putting out approx. 14VDC, so I took his word for it. Two days later, I go to start the bike, and the battery is completely dead. The heavy ass (and perfectly fine) AGM battery I took off of my 750 fit in the battery box and happened to have a full charge, so I put that in and the bike ran fine. Haven't had any problems yet and haven't had to recharge the AGM, but I'm expecting something to pop up. The stator was replaced recently, so I'm wondering if something happened to the Reg/Rec. before or after that swap. I have tons of experience dealing with my 750's electrical ghosts, so I can sort this out. It's just not fun.
- Air suspension. This one I can't tell if it's a problem, or if it's just the nature of the beast. But if it is a problem, it's an expensive one. The CB900c came with air suspension in the front and back. I've got it loaded to the maximum recommended pressure and it feels soft to me. The system doesn't leak, as I've checked it every time I ride and it's always the same. But when I ride, it feels really soft, and there seems to be more travel than one would expect. I also wouldn't be surprised if this bike bottomed out going over a bump with a passenger on the back. Maybe I'm just not used to the "cruiser" suspension. The rear is an easy fix/swap... but the front is a different beast. I know that the forks only use air for preload, and there's a steel spring for recoil. Would it be possible to just replace this spring with a stiffer, more progressive one?
That's all I've found so far. Paid a grand for it, and I've seen the same bike go for $1500 advertised as "runs great just needs some carb work." And it runs fine with the new battery. Actually, it runs like a beast. The cool thing about this 600lb bike is the Hi/Lo transmission. When they put in the jackshaft to get the drive over to the right side for the shaft, they put in Hi/Lo gearing. In low, the bike accelerates like a lunatic. In high, the bike runs at 60mph in top gear at ~3000rpm. Best of both worlds. It weighs a ton and handles like a pig though.
Overall I'm happy with it. But the valve cover bolt hole thing is pissing me off though. Still sore about that. If I can get it sorted out, it may be worth keeping the bike and turning it into a brat or something. But otherwise, I'm probably selling it at a huge loss once the 750 is done. Only got room for one 30 year old source of heartbreak in the garage.
Minor issues:
- Squealing brakes. This guy just replaced all the brake pads on the bike (two discs up front, one in the back) and they squeal at the slightest touch. The stopping power is great, so I'm kinda wondering where to start looking... The rotors have some surface rust but the calipers look great. I've never chased down an issue like this, so I could use some advice.
- Exhaust Rattle. The pipes are aftermarket. I figure they weren't installed correctly or there's something going on with the baffle inside. It only rattles at about 3000rpm.
- Leaky Carbs. No surprise here that a 30 year old Honda has a carb issue. There's no filter in the fuel line, and when I checked the tank I did see some gumming going on. The guy made a point of telling me that he always used premium, but that doesn't mean shit if you don't put stabilizer in the tank over winter. He had the carbs rebuilt two years ago (even gave me the receipt) but my guess is something just got up in there again. At the very least I'll have to clean out all the snot. I've done this twice before, so I know the drill.
Major Issues
- Stripped threads in valve cover bolt hole. This is the one I'm punching myself in the face for not checking. I knew there was an oil leak coming from the valve cover, but I didn't think to check the bolts. The guy had the valves set recently (again, another receipt), and I thought it was just a poor seat with the gasket. It would have been a deal breaker if I realized it was a stripped out bolt. At the very least, I would have asked for a much lower price. As it is, I walked away that day thinking I paid $500 less than it was worth, and now I think I overpaid. So what should I do here? Will a heli-coil work in this situation? The leak isn't horrendous. I lose about a teaspoon of oil per hour of hard riding I'd say. Probably less. Most of it ends up on my pants.
- Battery won't hold charge. One of the first questions you should ask when buying a DOHC honda from that era is "Are there any electrical problems?" With a straight face, this guy said "Nope. None at all." With the bike running, the system was putting out approx. 14VDC, so I took his word for it. Two days later, I go to start the bike, and the battery is completely dead. The heavy ass (and perfectly fine) AGM battery I took off of my 750 fit in the battery box and happened to have a full charge, so I put that in and the bike ran fine. Haven't had any problems yet and haven't had to recharge the AGM, but I'm expecting something to pop up. The stator was replaced recently, so I'm wondering if something happened to the Reg/Rec. before or after that swap. I have tons of experience dealing with my 750's electrical ghosts, so I can sort this out. It's just not fun.
- Air suspension. This one I can't tell if it's a problem, or if it's just the nature of the beast. But if it is a problem, it's an expensive one. The CB900c came with air suspension in the front and back. I've got it loaded to the maximum recommended pressure and it feels soft to me. The system doesn't leak, as I've checked it every time I ride and it's always the same. But when I ride, it feels really soft, and there seems to be more travel than one would expect. I also wouldn't be surprised if this bike bottomed out going over a bump with a passenger on the back. Maybe I'm just not used to the "cruiser" suspension. The rear is an easy fix/swap... but the front is a different beast. I know that the forks only use air for preload, and there's a steel spring for recoil. Would it be possible to just replace this spring with a stiffer, more progressive one?
That's all I've found so far. Paid a grand for it, and I've seen the same bike go for $1500 advertised as "runs great just needs some carb work." And it runs fine with the new battery. Actually, it runs like a beast. The cool thing about this 600lb bike is the Hi/Lo transmission. When they put in the jackshaft to get the drive over to the right side for the shaft, they put in Hi/Lo gearing. In low, the bike accelerates like a lunatic. In high, the bike runs at 60mph in top gear at ~3000rpm. Best of both worlds. It weighs a ton and handles like a pig though.
Overall I'm happy with it. But the valve cover bolt hole thing is pissing me off though. Still sore about that. If I can get it sorted out, it may be worth keeping the bike and turning it into a brat or something. But otherwise, I'm probably selling it at a huge loss once the 750 is done. Only got room for one 30 year old source of heartbreak in the garage.
