Adjusting valves

B

BNKN

Well-known member
Ex. calls for .007-.009 thou. .007 feeler goes in and drags out with considerable effort. What's the fudge factor in general? I check these often so it wouldn't be a ton of mileage before next check.
 
I would adjust. If the 007 goes in out easy and the 008 was tough then it's good. Typically I always strive for the largest gap.

But technically your still ok. But your already there why not just adjust?
 
Because it's really tight quarters to work. If I can safely leave it to next service (5000km) I'd rather do that. It shouldn't burn a valve at a tight 007?
 
Put your feeler gauge in the middle of a phone book and pull it out.That's what it should feel like.What does .006 feel like?
 
.006 feels like butta, .007 feels pretty tight but goes. It's amazing how that tiny bit can feel so different. Working in those tight quarters it's brutal adjusting to within a thou so will leave well enough alone. Thanx guys.
 
depends on the bike and valve type.
on some types the gap gets smaller as it wears, in that case your at the limit and needs to be adjusted.

on some valve types the gap gets larger, in that case your good.

need to know what bike and engine
 
StrickCBR said:
I'd leave it. If .007 goes in and out with a bit of effort, then its basically right on .007, which is spec. That will give you tons of km's before next check. I'd rather be at the tighter tolerance then the larger tolerance.

In engine terms, .007 is massive enough anyways.
Click to expand...

That's backwards. You want to be at the looser tolerance if you can be.
 
I'd rather have it on the loose end of the specified range than the tight end. If you are in there that far, you might as well finish the job.

Also, if the specifications are metric (and they are, on most bikes), use a set of metric feeler gauges. The intervals are finer.
 
Assuming your are working on the bike in your sig...

Bonne's are metric, and the specs are given in metric. The math is also way easier to do if you are working in metric as that's how the replacement shims are classified. Those bikes get loose as they wear. Set them right at the tighest range of the specs if you can.

As far as the "fudge factor" goes, 0.0005" (or half a thou) in either direction is not going to end the life of that motor. Based on what I read above, and assuming you are working on the Triumph in your signature, and assuming you are measuring properly.... etc, leave it alone they are fine.
 
Oops, sorry, the Bonnie is new to me this year. Zero miles. Working on my sons' DR650 pia.

Will probably take Bonnie to dealer. They get loose, huh?
 
Ah makes sense, cause the bonnie is a dream to work on for valves... thought you had lost your mind but didn't want to say so without at least asking. And yes, you will probably notice them start to make a ticking noise at like 6000 km and want to have them adjusted, after that they are good for 15000 - 20000 km usually.

As for the DR, just put the clearance in the middle of the range and enjoy. It's not a race motor, a thou in either direction is not that critical. It's important, but there is a range for a reason.
 
Thanks Iggy76.

Further to the DR650, there is a bolt head in the way on both IN. and Ex. that makes sliding the feeler very difficult. I just removed it. Bingo, still somewhat awkward but much better. Never saw that trick mentioned in any DR valve adjust thread.
 
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