79 mile 1980 c70 passport
- Thread starter Bruduf
- Start date
Congrats!
Can't really go wrong with this little mileage. If the engine feels (via kickstarter) like it has good compression, then your replacement parts list is going to be mainly rubber parts + brake shoes. Most of the work will be cosmetic clean-up. With so little chrome and solid colors, the project is very DIY-friendly and wallet-friendly. As for the gas tank, I'd start by cleaning it out. A quart of acetone is cheap and very effective. Then, you'll be able to see how much rust, if any, is inside. It may not be rusty at all. You'll probably want to replace the fuel lines, clean the carburetor...and figure out if you should throw a rebuild kit at it. With so few miles, there's a good chance it needs nothing more than a good cleaning and new rubber parts (i.e. petcock packing, bowl gasket, o-rings).
Can't really go wrong with this little mileage. If the engine feels (via kickstarter) like it has good compression, then your replacement parts list is going to be mainly rubber parts + brake shoes. Most of the work will be cosmetic clean-up. With so little chrome and solid colors, the project is very DIY-friendly and wallet-friendly. As for the gas tank, I'd start by cleaning it out. A quart of acetone is cheap and very effective. Then, you'll be able to see how much rust, if any, is inside. It may not be rusty at all. You'll probably want to replace the fuel lines, clean the carburetor...and figure out if you should throw a rebuild kit at it. With so few miles, there's a good chance it needs nothing more than a good cleaning and new rubber parts (i.e. petcock packing, bowl gasket, o-rings).
I cleaned the tank by filling with denatured alcohol and let it soak for2 days the a wire wheel on a rod and then WD 40 rust soak overnight tank came clean. Cleaned carb and have to get some new fuel lines .It has 150 psi of compression and great spark should start !!!!
Congrats...sounds like you snagged a mechanically new bike that could just do with some cosmetic freshening.
If you're seeing 150psig, then the engine is probably like new, internally. I would strongly recommend you learn how to clean the oil spinner...that's the chamber located behind the throwout bearing flange, inside the face of the clutch...not just the oil screen. I do the initial/break-in oil spinner cleaning at the 300-mile mark, it's cheap insurance. There will be a surprising amount of shiny metal bits & clutch debris inside. Thereafter, annually or every 1000 miles (if you cover a lot of miles) will keep the engine clean and free of the clutch debris and metal particles that often leave these engines in need of rebuilding by the 2K mile mark. Beyond that, a few short-interval oil changes, especially for the initial 500 miles and using known, high-quality, bike oil (JASO-spec/wet clutch compatible) such as Honda GN4, Valvoline, Castrol, is all it takes to get well into 5-digit service life from one of these little motors.
I'd also recommend using clear, inline, fuel filters. Place them as close to the carb inlet as possible, especially if you use rubber fuel hose...it's highly susceptible to 2020 era pump fuel. If you see rust particles, or what looks like threads, accumulating you'll know there's a problem upstream of the carb...with ample warning. If this were mine, I'd use Tygon fuel hose. It's transparent enough to see dirt and air pockets and doesn't dissolve when exposed to E10.
If you're seeing 150psig, then the engine is probably like new, internally. I would strongly recommend you learn how to clean the oil spinner...that's the chamber located behind the throwout bearing flange, inside the face of the clutch...not just the oil screen. I do the initial/break-in oil spinner cleaning at the 300-mile mark, it's cheap insurance. There will be a surprising amount of shiny metal bits & clutch debris inside. Thereafter, annually or every 1000 miles (if you cover a lot of miles) will keep the engine clean and free of the clutch debris and metal particles that often leave these engines in need of rebuilding by the 2K mile mark. Beyond that, a few short-interval oil changes, especially for the initial 500 miles and using known, high-quality, bike oil (JASO-spec/wet clutch compatible) such as Honda GN4, Valvoline, Castrol, is all it takes to get well into 5-digit service life from one of these little motors.
I'd also recommend using clear, inline, fuel filters. Place them as close to the carb inlet as possible, especially if you use rubber fuel hose...it's highly susceptible to 2020 era pump fuel. If you see rust particles, or what looks like threads, accumulating you'll know there's a problem upstream of the carb...with ample warning. If this were mine, I'd use Tygon fuel hose. It's transparent enough to see dirt and air pockets and doesn't dissolve when exposed to E10.
I'd set the point gap at 0.016". If you're getting good spark, the points & condenser should be fine. The WOT non-response sounds to me like a carburetion issue. The most likely problems: clogged/degraded airfilter, pinched air inlet tube, partial blockage of the main metering circuit...most likely the emulsion tube wall orifices. That's all stuff that can be tested for free, before ordering parts.
Bogging at full throttle indicates a lean condition. Overrich usually manifests as strong throttle response and high-rpm misfire, that prevents the engine from revving-out cleanly.
Bogging at full throttle indicates a lean condition. Overrich usually manifests as strong throttle response and high-rpm misfire, that prevents the engine from revving-out cleanly.
