Would You Adjust These Valve Clearances?

My '05 DR-Z 400SM has 8,253 miles and this is the first time that I've checked the valve clearances. I purchased the bike with 4,500 miles from the original owner who says that the valves "were in spec" at 2,500 miles. Unfortunately, I have no record of the previously measured clearances.

The feeler gauge set I'm using has the following increments:

.004in (.102mm)

.005in (.127mm)

.006in (.152mm)

.007in (.178mm)

.008in (.203mm)

.009in (.229mm)

.010in (.254mm)

.011in (.279mm)

.012in (.305mm)

The Suzuki specification is:

Intake: .1-.2mm (.0039-.0079in)

Exhaust: .2-.3mm (.0079-.0118in)

My clearances measured as:

Intake - Clutch Side: .007in (.178mm)

Intake - Brake Side: .005in (.127mm)

Exhaust - Clutch Side: .010in (.254mm)

Exhaust - Brake Side: .009in (.229mm)

Technically, my valves are all in spec. Would you go through the trouble of pulling the cams to bring the clearances closer to the larger side of the spec? Are there any performance or longevity benefits to be had by doing so?

Whether I make adjustments now or not, my intention is to check the valves more regularly as it takes less than 30 minutes. With the current clearances recorded, I can now watch for any movement in the future.

Thanks for your input!

good to go

I had an exhaust valve at .229 for 8 years. Once it settled in, it stopped moving. They all sat steady as rocks. Keep the air filter clean, grease the seal, don't test the rev limiter and the stock DRZ valves should last a long time. I would ride it. Actually, I did - for 8 more years. My specs were similar :thumbsup:

good to go
I had an exhaust valve at .229 for 8 years. Once it settled in, it stopped moving. They all sat steady as rocks. Keep the air filter clean, grease the seal, don't test the rev limiter and the stock DRZ valves should last a long time. I would ride it. Actually, I did - for 8 more years. My specs were similar :thumbsup:

Thanks for the input! I didn't think it was worth it and your feedback confirms it.

MrMaxP0WR,

Thanks for posting this up.

A couple of my clearances are pretty close as well, and I was wondering the very same thing.

dont touch them yet. Adjust them when they measure OUT of spec.

after owning way too many 16 valve bikes I'm of the school "if there is clearance, they are fine".

I had an exhaust valve at .229 for 8 years. Once it settled in, it stopped moving. They all sat steady as rocks. Keep the air filter clean, grease the seal, don't test the rev limiter and the stock DRZ valves should last a long time. I would ride it. Actually, I did - for 8 more years. My specs were similar :thumbsup:

exactly !

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