Valve clearance question; precedural

[bcware]

First time adjusting valve clearances!

When inserting the feeler gauge between the valve and rocker arm should the feeler be able to pass completely through (between) them? I can only get the in-spec feelers about 3/4 of the way through, so I am assuming the gap is too tight.

I also need to make sure I am not holding the feeler at an angle...

Thanks for any help!

 

[xschris]

Should be a slip through fit with just a little drag. .004 intake -.007 exhaust, cold (for those who don't know)

 

[bcware]

So it should pass all the way through though? It is getting hung up about 3/4 through.

 

[xschris]

Yes, all the way.

 

[xs400neophite]

hahaha glad to see that I am not the only one that had problems with this!
http://www.xs400.com/forum/showthread.php?t=7170&highlight=adjusting+valves

 

[bcware]

Ok, it was successful. The right cylinder has always been leaner than the left. The left was in spec. The right was a bit tight. I also installed new points, a new condenser, new plugs, and set the timing.

I am looking forward to a test ride

 

[drewpy]

I bend my feelers in order to get the correct gap. You can buy them already angled but its cheaper to do them yourself.

 

[HoughMade]

Yeah, I was going to suggest that. Also, to make things simple for myself, I use a "go-no go" procedure. I set it to the clearance I want (usually in the middle of the spec) then make sure the next thinner blade is way loose and the next thicker won't fit in at all. If that's the case, I know the clearance is in spec.

 

[domains]

I cut the feeler inhalf and give a 90degree bend on them... or you can buy 90degree feelers

.004 example .005 will not fit

 

[bcware]

I ended up bending the straight feelers; I couldn't find a bent set with small enough blades locally. The tune-up made quite a difference; the idle is much more steady now. The old points were pitted. Before the tune-up she was dying at idle randomly and it was getting progressively worse.

 

[JARichmond]

So then would valves that have been loosened over time (simple wear) lead to a richer mixture?

 

[bcware]

From what I have read valves tend to tighten over time, not loosen. Tight valves are not allowed to seat properly and shed their heat; this leads to burned valves.

When the valves are out of spec in general all sorts of wonky things can happen, but it really depends on which valves, what they are doing, and when they are doing it.

 

[Drewcifer]

Late to this party...

Mine had to be heated and bent to be slipped in. Choose one that is in the middle of the range, leaving a few thou in either direction. Lower valve until snug on feeler, back out screw 1/4 turn, tighten adjuster, done. (You can afford to turn the screw 1/4 tighter because you left the extra few thou, remember?)

Simple as pie.

 

[domains]

You get ware on the rockers so the valves loosen.

 

[226dark]

From what I have read valves tend to tighten over time, not loosen. Tight valves are not allowed to seat properly and shed their heat; this leads to burned valves.

When the valves are out of spec in general all sorts of wonky things can happen, but it really depends on which valves, what they are doing, and when they are doing it.

Is that true? if so I set mine at the minimum spec. and should check them again. Since March have put on 3300 miles on rebuild.

 

[bcware]

Dan says over time a properly running valve works its way into the head, reducing clearance and therefore tightening over time. He says valves only loosen if there are lubrication problems in the top end.

http://www.dansmc.com/valveclearence.htm

First few paragraphs.

He's no rocket scientist, but he's very, very experienced.

 

[drewpy]

You get ware on the rockers so the valves loosen.

it depends.

if the valve seat recesses, then it tightens up. Common in bikes.

rocker adjusters can wear, but are bathed in oil and are away from the damaging heat.

 

[HoughMade]

Dan says over time a properly running valve works its way into the head, reducing clearance and therefore tightening over time. He says valves only loosen if there are lubrication problems in the top end.

http://www.dansmc.com/valveclearence.htm

First few paragraphs.

He's no rocket scientist, but he's very, very experienced.

This is correct.

 

[Tombo]

Yah know - the valves SHOULD tighten over time (they have been in my 1980 XJ650 over the past 5k) - but I just experienced them loosening on my xs. I set valve clearances to mid-spec (.10 intake, .18 exhaust) about 300 miles ago, and then the other day after about a 60 mile round trip cruise with my girlfriend (who rides a honda rebel, so I assure you I wasn't revving too hard!), I noted loud ticking in the top end, noticeable while idling. Having just done my valves just 2 to 3 weeks ago, I was a bit concerned, but decided I'd check it out later.

Tonight after the Giants beat the Tigers in game 3 of the world series - I decided to at least go and investigate. I was surprised to find that the left side was out of spec, only just (a loose .20 exhaust, .13 intake). The right side was totally fine.

I am not sure what could have caused this to happen, aside from wear to the rockers? Seems like a pretty substantial change to take place in such a short time period. Should I be worried about this?

 

[226dark]

Maybe locknut was not as tight as should have been??