All Hondas are properly assembled at piston-to-cylinder clearances that elicit blank stares from automotive machinists. The CB350F's tiny pistons are derived from some of Honda's earliest single-cylinder tiddler engines and thus like them Honda specifies the least clearance of all of their bikes on this engine. Really close clearance. As in 0.0003". Yes, three ten-thousandths.

Careful machining and assembly can not only eliminate oil consumption issues but also offers added power potential. The CB350F engine can be made to acquit itself surprisingly well without resorting to "high performance" parts. I have a lot of experience with this.

This engine's camshaft wears faster than the camshafts in the other SOHC fours, which themselves are known for rapid wear. Replacement stock cams are available and are the perfect choice for use in rebuilds.

The rubber washer on the rear brake torque arm goes on the outside of the arm, not on the inside.

The second-most important carburetor rebuild part--the float valve--is still available (though very expensive). Unfortunately, the most important part--the needle jet--is not.

The Keyster needle jet for the CB500/550 has proved to make a good substitute. Contact Sirius Consolidated in Canada, a Keyster outlet.

There are two more reasons this model seems to run excessively rich, and neither have to do with the need to rejet the carburetors or alter the float level. One is a seat that bows down onto the airbox intake horn ("snorkel"). I have even seen a heavy rider bend the seat hinges. The other is the fact that more than fifty year old carburetor floats change their composition and thus their buoyancy. Replacement of these floats has solved many excessive richness complaints on the 350 four.

Carburetor removal and reinstall is easier if the battery is removed and the battery box unbolted and pushed back.

The intake manifolds are not all the same. The middle two are different from the outer rwo. They are numbered from the factory.

As with all vintage Hondas, the CB350F front disc brake is best maintained by using silicone brake fluid in the system.

Also like its brethren, the CB350F benefits significantly from full-metallic front brake pads.

Front brake squeal is easy to fix, and it's not by doing any of the things found on forums. Gaskets cut from a cereal box and placed behind the moving pad has been the traditional fix for as long as Hondas have had disc brakes.

Speaking of forums, they are not really good places to get advice. Believe me, they know a lot less than you do. Look around on my website and see how much forums are ignorant about.

As already mentioned, there is no need to alter the carburetor specifications on a completely stock bike. Altitude however does make a slight difference and for best results should be accounted for. One size on the main jet (that's 0.02mm) is usually enough.

Correct clutch adjustment is always neglected on this Honda, as with most 70s Honda fours.

The cam chain tension on the CB350F is done in a non-intuitive and very different way from the other SOHC fours. Consequently, the CB350F tensioner is probably the most often damaged through misadjustment. See my article on this.

Like the CB500/550, the CB350F does not have a primary chain tensioner. So at a very low idle--especially when cold or if the tune is not particularly sharp--the engine will rattle. But this can be all but eliminated through proper engine tuning. And even a very worn chain that will rattle even with perfect engine tune makes very little noise.

Just as the engine shares many design features with that of the 500/550 series, so do the 350F's carburetors. Great carbs, simple carbs, wonderfully functional carbs. But corroding like crazy due to their zinc construction and badly man-handled by incompetent mechanics.

The CB350F, like the CB500/550, has the most aggravatingly slowest-pulling throttle of all Hondas. Fortunately, this is easily remedied, and to very good effect. And, without buying any parts.

Don't use aftermarket oil filters. They are not as good, no matter what anyone says.

Don't use premium gas. This bike like all of Honda's 70s roadbikes was designed to work fine on 87 octane and putting in premium will hasten carbon buildup on the valves.

Speaking of the engine's valves, the little four suffers from the same issue that nearly all pre-1990 Honda four-stroke do, rapid valve recession that steadily robs it of cylinder compression.

If your bike is a daily rider, don't fit 1970s-spec, original block thread tires. Those are for showbikes. More modern tires will save your butt and are the only thing that makes sense.

This little bike can be made to acquit itself nicely through a small number of very simple techniques. For example, 400F pistons work well with just a tiny bit of massaging. The engine responds to cam degreeing also. And knowledgeable ignition service--and I don't mean Dyna parts or brightly colored plug wires--makes a welcome difference too.

Expertly set up, the stock ignition is up to anything you demand of it. It is in no way inferior to any of the aftermarket substitutes, despite forum narratives.