VintCo Valve Train

VintCo Valve Train Parts: Precision Shims for Classic Bikes

When it comes to keeping a vintage motorcycle running at its best, few components demand more precision than the valve train. Valve clearance — the measured gap between the valve stem and the rocker arm or cam follower — is one of the most critical tuning parameters on any four-stroke engine. Too tight, and valves can burn; too loose, and performance and reliability suffer. For classic motorcycle restorers and vintage off-road racers, sourcing shims to the exact specification of decades-old engines is often the hardest part of the job. That's where VintCo steps in.

VintCo's Specialty: Vintage Valve Shim Kits

VintCo is a dedicated supplier of hard-to-find parts for vintage motorcycles, with a catalog spanning marques like Bultaco, CZ, Honda, Husqvarna, Kawasaki, KTM, Maico, Suzuki, Yamaha, and many more. VintCo's Vintage Valve Shim Kits are available in a universal fit format , making them a go-to solution for restorers working across multiple platforms.

What sets VintCo's valve train offering apart is its meticulous approach to shim sizing. Their Valve Shim Kits are available in multiple diameter configurations — including 13mm, 25mm, 29mm, and 29.5mm — with shims offered in 0.05mm increments , giving builders the fine-grained control needed to dial in correct valve clearances on engines that may be decades old and worn beyond their original tolerances.

Customers have noted the real-world accuracy of these shims: one reviewer confirmed using VintCo's 29.5mm Valve Shim Kit to dial in clearances on a 1982 Suzuki GS550 Katana, noting they "measured them with calipers and were accurate."

Why Valve Shim Precision Matters on Classic Engines

The engine's valve train mechanism is designed to open and close the intake and exhaust valves, and depending on the location of the camshaft in its rotation, the valves open and close via its lobe height. On vintage SOHC and DOHC engines — which are common in the classic Japanese and European bikes VintCo serves — shim-under-bucket or shim-over-bucket designs require extremely precise shim thickness to maintain correct valve lift and timing. If airflow is restricted, the efficiency and power of the motor will decrease, and every part performs a key function within the valvetrain to help regulate the intake fuel mixture and exhaust gasses to produce power correctly.

Unlike modern bikes where dealers can still source OEM shims, vintage motorcycle owners often face discontinued parts, expired supersession chains, or simply unavailable factory stock. VintCo fills this gap with complete shim kits — multiple shims per size — so a builder can select the correct thickness during assembly rather than waiting on back-ordered individual pieces.

Who Should Shop VintCo Valve Train Parts?

VintCo's valve train parts are ideal for restorers working on vintage motocross and enduro machinery from the 1970s and 1980s, as well as vintage road bike enthusiasts refreshing top ends on aging inline-fours. Whether you're competing in vintage motocross events or returning a classic to street duty, having the right shim thickness on hand is essential. Browse the full Valve Train category to find the right kit for your application, or visit the VintCo brand page to explore their broader catalog of vintage motorcycle engine parts.