How tight should feeler gauge be during valve check?

[jblaze5779]

While checking my valves on my new to me 2004 1150rt I noticed that the appropriate feeler gauge for each set of valves was able to be inserted but was very, very tight.

 

From what I've read in my research, there should be a light tug on the gauge... I felt like I was forcing it in there and yanking it out. Should they be that tight or are they fine as long as I can get it in there? The next larger size gauge could not be inserted into the the space.

 

What are the implications of the valves being too tight?

 

Thanks for your help.

 

 

[tazplas]

My years of working alongside fitters has told me that you should feel a light scraping fit.(small resistance when inserting and removal) Don't force them.

 

As for having the gaps too small or too large, i'm no mechanic so i will let others answer that one. I believe burnt valves could be a sympton of overly tight clearances?

 

Perhaps someone more enlightend than me should comment.

 

Cheers

 

Steve

[taosports]

I read somewhere that it should feel as smooth as stroking a butter knife through a stick of room temperature butter. Anyway, that's the advise I follow and it's worked for me for over 50k miles.

 

 

[John Dickens]

A 'light sliding fit' is how I've always heard it but a while back, as a present, I was given a set of 'stepped' feeler gauges (go, no-go) where each blade has two sizes, eg 0.011"/0.013".

 

These are brilliant.

 

If you are setting a 0.012" gap you use the 0.011"/0.013" gauge and if the 0.011" goes in but the 0.013" doesn't then you are there.

[David]

My approach is to make sure I don't have to push hard to get them in there, but they should be tight enough that I can let it dangle on it's own without falling to the floor. That has always been a very simple and easy way to get them consistent.

[John in NC]

If the correct size goes in but the next largest size does not then you got it.

[ElevenFifty]

Just a bit of 'sticktion' ... I use two .030 and two .015 guages ... the short ones with a plastic handle are my favorites.

 

I consider the job done when all four guages can be inserted and there is enough 'stick' so that they can be moved to the horizontal and will stay there, supporting their own weight. I can slide any one of them without difficulty, but if I release it, it stays put.

 

If you use this 'four guages' method, you'll be surprised to find a slight change in one valve will affect another.

 

Last couple of times I've taken off the covers, inserted the guages, and just put everything back together ... 15K or so, since I had to make any adjustment.

[flars]

Loose is better than tight. As noted by others, the gauge should fit in easily and slide around without too much drag.

It's a good practice on these bikes (but not absolutely necessary) to have two feeler gauges for the intake and two for the exhaust. This way you know that the gaps from one valve aren't affecting the gap on another valve (i.e. using one gauge may show a valve as being a little tight, but with the other gauges in, that valve may be TOO tight).

[jblaze5779]

Thanks for the info guys. I think after reading your posts mine may be too tight.

 

Right now I'm using the long thin kind... they're long enough to bridge the gap between the two valves on either the intake or exhaust side. Like I said before I've really got to press them in there and then they are in there for good until I yank it out.

 

 

 

 

[Joe Frickin' Friday]

I used to bring a micrometer to Tech Daze events. Slip in a 0.006" feeler gauge, dial the mic down to 0.0060". That way you could show people what it's truly supposed to feel like.

 

Two things make this kind of thing pointless:

 

1. Most people of course don't have access to a micrometer, and

 

2. You just don't need this kind of precision when adjusting valves.

 

Some people will regard #2 as heresy, but here's the thing: for engine longevity, the exact clearance is not particularly important, as long as you have "enough" clearance. 0.006"? 0.007" (0.012"-0.013" for exhaust)? Your engine will make it to 200K+ miles either way. Even 0.005" (0.011" for exhaust) would probably be OK, though if you err in this direction, you're trimming the safety margin that was prescribed by the designers.

 

The precision you DO want is about making sure the clearance feels the same for all four intake valves; note that this is not about engine longenvity, but about smooth running, facilitating a good TB synch and keeping the dreaded "surge" away. Doesn't matter what they feel like (within reason; see below), as long as all four intake valves feel the same. (it's good practice to shoot for the same feel on the exhaust valves too, but not nearly as important for smooth running.)

 

So instead, a suggestion: find out what "definitely too tight" feels like, then pick a "feel" that's somewhere between "too tight" and "falls out on its own," and try to achieve that same feel on all four intake valves.

 

Procedure for finding out what "too tight" feels like:

Crack open your valve cover, stick a feeler gauge in the valve/rocker gap, and screw the adjuster in until it's very obviously holding the valve off of its seat (you should see the spring move as you screw in the adjuster). Try to move the feeler gauge around. Feel how tight that is? That's "definitely too tight." When the feeler gauge has this much friction on it, you know you're holding the valve open and you've definitely got less clearance dialed in than the feeler gage thickness. Back the adjuster out until the valve comes to rest on its seat and the friction on the gauge eases up. When the friction is somewhere closer to "gauge falls out on its own," you know you're safe. Lock the adjuster down, verify the clearance/friction one more time, and you should be good to go.

 

Now shoot for that same friction level on the rest of the valves.

[jblaze5779]

OK cool... throttle cable assembly should be here today and I might be able to get everything wrapped up and be back on my bike tonight.

[Redbrick]

A 'light sliding fit' is how I've always heard it but a while back, as a present, I was given a set of 'stepped' feeler gauges (go, no-go) where each blade has two sizes, eg 0.011"/0.013".

 

These are brilliant.

 

If you are setting a 0.012" gap you use the 0.011"/0.013" gauge and if the 0.011" goes in but the 0.013" doesn't then you are there.

 

:thumbsup:"Over-Under" is a good way to check settings.....Also a good idea on the 4 valve boxer to have feeler guage blades in both valves you are adjusting (i.e., both intakes) as tightening one can effect the other....It's a back-and-forth operation until you get that even, slippy feeling on both ...

[ShovelStrokeEd]

Here's what I do.

Get the piston somewhere close to TDC compression.

Crack the adjuster lock nuts.

Back off the adjuster till the feeler gauge pretty much falls into place. Now, using the long end of the hex wrench, I spin the adjuster in using my fingers only on the stem of the wrench, not the bent part. It will stop with only very little pressure on the wrench. Now feel the drag on the gage and then tighten the lock nut. If the drag changes, repeat for that valve. If it doesn't change move on to another valve.

 

These days, I don't own a bike for which this method works, rather, I have to insert and remove a series of gauges to determine valve clearances and then make a map of all of them, 12 in my case. Then I decide which, if any, valves need to be adjusted, pull the cams, pull the shims and measure them with a micrometer. Another map and a couple of egg cartons to keep parts in position. Then I do a little head scratching to see if swapping shims into different positions will solve the problem or do I have to run to the dealer to buy a shim or two. Once that decision and action is taken, in with the new shims, back on with the cams and reset cam timing. One more pass over the valves with the feeler gauges to confirm that the adjustment(s) worked. If all is well, back on goes the cam cover, coils, air box, the tank and plastic and I'm nearly ready to fire it up and ride.

 

Be thankful for your Boxers.

[KDeline]

 

 

These days, I don't own a bike for which this method works, rather, I have to insert and remove a series of gauges to determine valve clearances and then make a map of all of them, 12 in my case. Then I decide which, if any, valves need to be adjusted, pull the cams, pull the shims and measure them with a micrometer. Another map and a couple of egg cartons to keep parts in position. Then I do a little head scratching to see if swapping shims into different positions will solve the problem or do I have to run to the dealer to buy a shim or two. Once that decision and action is taken, in with the new shims, back on with the cams and reset cam timing. One more pass over the valves with the feeler gauges to confirm that the adjustment(s) worked. If all is well, back on goes the cam cover, coils, air box, the tank and plastic and I'm nearly ready to fire it up and ride.

 

Be thankful for your Boxers.

 

 

That's one big reason I stay with the twin cyclinder BMW. To me that is just to much work.

[ironox]

Of course, you can chuck it all and take it to a dealer, and ride away in wedded ignorance as to what has happened. I like this method!!

[jblaze5779]

naw that's not me.... I gotta know what's going on in there... it's the engineer in me..

 

I just checked them again tonight armed with the knowledge gained in this thread. This time I couldn't even get in the recommended feeler for all the valves. I loosened and adjusted them to achieve a slight tug, they were just able to hold the gauge out horizontally. Once I get my throttle and fuel tank on I'll see how it works.

[Spyder]

jblaze, before you button it up, check your throttle body sync as well.

[jblaze5779]

yes sir that's on the list too

[rdsmith3]

I've only done this twice, so I am no expert, but I can slide the feelers in and out relatively easily, with slight resistance, but there is enough resistance to hold them in place. See pic but ignore arrow and lousy Blackbery camera.

 

It is easy to adjust valves on a boxer engine, and even easier on a naked bike!