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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: Bob T on April 19, 2012, 07:59:25 AM

Title: Valve clearance (4V motor) questions
Post by: Bob T on April 19, 2012, 07:59:25 AM

Checked my valve clearances last night for the first time.  Bike is a '95 K11RS with 33K miles.

I was using standard feeler gauges with metric markings, so I had .127mm, .152mm, .178mm, etc.  You all know what I am talking about...(going to pick up a metric set soon).

Anyway...it appears I have one tight valve on the intake.  .152mm (.006) won't go, .127mm (.005) goes easy....

Question #1: Should I go through the trouble of adjusting the valve clearance to correct this one valve?

Question #2: The valve cover had some silicone sealant between the rubber gasket and head.  Is this normal?  If so will any gasket sealant work, or should I use some specific?

Thanks!

Title: Re: Valve clearance (4V motor) questions
Post by: wmax351 on April 19, 2012, 10:15:50 AM

Usually, you want the intakes on the tight side of spec, and the exhaust on the loose side. You also want them equal to each other, so much as is possible. I would bump them all to ~.15+ mm.

I would say at the tightest, you want .006 go, .007 no-go.

The valves recede faster with lower miles, and (overly) tight clearances can lead to burnt valves.

What are your other clearances?

Title: Re: Valve clearance (4V motor) questions
Post by: Bob T on April 19, 2012, 03:22:41 PM

Quote from: wmax351 on April 19, 2012, 10:15:50 AM

Usually, you want the intakes on the tight side of spec, and the exhaust on the loose side. You also want them equal to each other, so much as is possible. I would bump them all to ~.15+ mm.

I understand the cam followers come in .05mm increments, so I am not sure how you would do that.  If I am at .14mm, I could go to .19mm., etc.

Quote

What are your other clearances?

The other valves are within spec.

But, question number one still remains...should I bother to go through the whole adjustment procedure for one valve that is .01-.015mm on the tight side?  Will my motor self-destruct on our first 1000 mile weekend?  Or can I let it go for now? :dunno

As for question #2, I found the answer with a little searching...   :embarass:

Thanks,

Title: Re: Valve clearance (4V motor) questions
Post by: wmax351 on April 19, 2012, 03:34:35 PM

You're probably fine for now. I'd check it in a little while. Maybe bump them all to .19 later.

Title: Re: Re: Valve clearance (4V motor) questions
Post by: Bob T on April 19, 2012, 04:19:23 PM

Quote from: wmax351 on April 19, 2012, 03:34:35 PM

You're probably fine for now. I'd check it in a little while. Maybe bump them all to .19 later.

Thanks...I will...