I have a 1973 CL350 which I am currently getting back on the road. They are fantastic bikes, largely because they are robust, dead simple and Honda made tens of thousands of them. Having said that, they did have some components that have not aged well.
The number one flaw on these bikes in my opinion is the stock carburetors. Honda used a constant velocity type carburetor which in theory provides very smooth throttle action and is easier to ride. In reality the vacuum diaphragm is a very delicate part that frequently fails with tiny air holes that leak vacuum, causing a mismatch in the throttle input between the cylinders (twin carb two cylinder, one per cylinder). This is a similar failure mode to your modern Suzuki air pressure sensor failing.
The other pain point is the mechanical points in the ignition system. This is an area of constant fiddling with adjustment and new condensers. It's much preferred to simply replace the points system with a "modern" (1980s technology) electronic ignition system. This removes the moving parts and greatly extends the life of a tune-up.
Old bikes are super cool and the 350 platform is a fantastic one but even back then bikes had "high tech" parts that did not age well and gaps where better tech had not been invented. The great thing about the 350 platform is that due to its popularity people are still coming up with solutions. In this way a Honda 350 is similar to Unix.
The number one flaw on these bikes in my opinion is the stock carburetors. Honda used a constant velocity type carburetor which in theory provides very smooth throttle action and is easier to ride. In reality the vacuum diaphragm is a very delicate part that frequently fails with tiny air holes that leak vacuum, causing a mismatch in the throttle input between the cylinders (twin carb two cylinder, one per cylinder). This is a similar failure mode to your modern Suzuki air pressure sensor failing.
The other pain point is the mechanical points in the ignition system. This is an area of constant fiddling with adjustment and new condensers. It's much preferred to simply replace the points system with a "modern" (1980s technology) electronic ignition system. This removes the moving parts and greatly extends the life of a tune-up.
Old bikes are super cool and the 350 platform is a fantastic one but even back then bikes had "high tech" parts that did not age well and gaps where better tech had not been invented. The great thing about the 350 platform is that due to its popularity people are still coming up with solutions. In this way a Honda 350 is similar to Unix.