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Are all motorcycle valve shims the same?

Are all motorcycle valve shims the same?

They are the same.

Can you reuse valve shims?

As for reusing, new shims where you can, reusing old ones not the end of the world, but do require that you confirm thickness with micrometer.

What are valve shims?

Shim-over-bucket “adjusters” In this design, an inverted “bucket” sits over the valve stem, and a shim sits atop the bucket to create the necessary lash. One can’t really “adjust” the valve lash on this setup. To change the clearance, the shim is replaced with one of a different thickness.

What is the purpose of valve shims?

The shim is a small disk that sits under the valve bucket and acts as a spacer. As the valves wear out, the clearance gets tighter and a thinner shim needs to be placed under the bucket to keep the correct amount of clearance.

Should valve clearance be tight or loose?

The thing is that as the valves and seats wear the clearances get tighter. Tighter valves will not make any new noise. When the intake valves get too tight they will cause hard starting and poor idling.

Are valve shims universal?

Yes, all year YZ,WR 400,426, and 450’s use the same shims. The Yamaha part numbers are the same, so if you ask for 450 shims they’re going to be the same thing.

How many times can you shim valves?

The rule of thumb for most mechanics is to shim the valves twice. After the valves have moved (almost always tighter) twice, it is time to replace them to minimize wear on the seats. 01 Remove all the parts in the way of the valve cover: seat, tank, shrouds and, on some models, the radiators.

What happens if valve clearance is incorrect?

Too much or too little valve clearance can result in poor performance or a rough idle because the engine can’t “breathe” normally and operate at peak efficiency. If there’s too little valve clearance, the valves won’t fully close, causing excessive heat, and the engine will lose power.

What happens if valve clearance is too small?

How do I know if my valves are too loose?

If the valve clearance is too small; the valves will never fully close, when they should. As a result, this will eventually burn part of the valve surface off; causing a constantly misfiring engine. On the other hand, if the valves are too tight; the engine may be running rough, either cold, hot or all the time.

How much does it cost to shim valves?

How Much Does A Valve Adjustment Cost? A typical shop will charge about $150 to adjust the valves on your 4 stroke dirt bike. This is because it’s quoted as a 2 hour job at an average $75/hour shop rate.

What happens if valve lash is too loose?

If the valve clearances get too loose, this will lead to a noisy running engine. Consequently, this will eventually damage the camshaft lobes; rocker arms ( if equipped ) and the tips, of the valves themselves.