DR 350 valve adjustment

When is it time to have the valves adjusted on a '90 DR350? Getting a little tap for a while now. Is it easy to do? Should I just have a shop do it for me? Otherwise she runs like a champ.

I just did mine on my '92 DR350s. Refer to a shop manual. Take side covers off. Seat. Tank. Loosen coil to swing it out of the way, and the horn too. Take the spark plug out, and the two round access covers on the shifter side of the crankcase. With a socket through ghe large access cover, turn the crank counterclockwise until you see the "t" timing mark align with the smaller hole in the front of the case. (Shop manual photos help clarify). The mark is there to show you when the rocker arms are NOT being actuated by the cam lobe. In this "relaxed" state, there should be a small amount of clearance between the tip of the adjuster and the top of the valve stem. That's what you will be measuring. See your manual for the spec as intake and exhaust sides differ. Take the two tappet covers off the top of the cylinder head and take your initial measurements. Oftentimes as the valve train wears, you'll see valve clearances get tighter, especially on the exhaust side. You'll want an 8mm closed end wrench, a way to hold the square top adjuster, and a set of good feeler gauges that go down to .002 inch. You will find the adjuster is very sensitive and 1/16 to 1/8 of a turn can take you out of spec. If this brief explanation plus the shop manual directions and photos have you puzzled, get a friend that has done it before to help walk you through it the first time. Good luck!

A little tip is that the adjuster nut is the same size as a number two square drive bit, and a valve adjustment tool can be easily made with a stainless #2 square drive deck screw. It's an easy job that you should be able to do in a half an hour.

The manual says to drain the engine oil , I didn't have to do that with the 650 .  

The manual says to drain the engine oil , I didn't have to do that with the 650 .  


I can envision why. I've done it numerous times without draining the oil.

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