Just checked valves and a little confused...

[treybrad]

Ok, so I'm not really sure why I thought my valves were tight, I could have swore they were last time I checked.... But 3 are loose and one is tight.

My right side exhaust is .09mm w/ a 2.65mm shim, left side exhaust is .10mm w/ a 2.68mm shim.

Right side intake is .10mm w/ a 2.60 shim, left side intake is REAL tight. < .03mm w/ a 2.60mm shim, but I can still spin the shim in the bucket.

I guess my question is... does that really make sense? Just one valve being tight like that? I tried it a few times, spinning the shim to different positions and turning the engine over and checking it in a couple different positions to make sure I was getting an accurate read...

The other question is, do valves have a tendency to go loose or tight? Seems like they go both ways from reading old posts... My loose ones are barely on the loose side, so if they're getting tighter and I replace the shims.... they'll be too tight. Should I replace them anyway?

Anyway, the tool from davidpu worked like a charm and those .03mm feelers did the trick too. Just looking for some advice on what you guys would do about my shims before I go ordering some...

trey

[The Buddha]

OK you'd note the clearances and let it run ... next time You open it make note again ... 2-3 times you'll know which way its going ... now just swap that tight one and ride it for 3-4K ... and check ...
Cool.
Srinath.

[Kerry]

My right side exhaust is .09mm w/ a 2.65mm shim, left side exhaust is .10mm w/ a 2.68mm shim.

Right side intake is .10mm w/ a 2.60 shim, left side intake is REAL tight. < .03mm w/ a 2.60mm shim, but I can still spin the shim in the bucket.

So, your current situation looks like this:

Code Select Expand


                  FRONT (Exhaust)

      .10mm / 2.68                  .09mm / 2.65

     <.03mm / 2.60                  .10mm / 2.60

                   REAR (Intake)


Personally, I would shoot for the following:

Code Select Expand


                  FRONT (Exhaust)

      .08mm / 2.70                  .06mm / 2.68

     <.08mm / 2.55                  .05mm / 2.65                

                   REAR (Intake)

Which means that you only need to buy two shims: a 2.55 and 2.70.

(While you're buying, consider getting a "test shim" for next time.  The 2.15 is SOooo thin ... I would recommend a 2.35 or 2.40)

[treybrad]

Thanks for the suggestions. I did get a 2.50mm shim as a "test". Hopefully they'll never get that tight. I also bought a 2.55mm, 2.75mm, and 2.70 so it should look something like...

Code Select Expand



.03mm/2.75mm                    .04mm/2.70mm

< .08mm/2.55mm (maybe 2.50?)    .05mm/2.65mm



Thought I'd go ahead and get a few while I was ordering, hopfully they'll be here by the end of the week. I'll open her back up in a few thousand miles and see which way they're going and adjust if necessary. Only one that is really very troublesome is the left exhaust.. it's either going to be .08mm or .03mm. Since it was so loose this time I figure it's getting looser so why not stay on the tight end  :dunno: . Oh well, hopefully it'll work out.

trey

[Kerry]

Only one that is really very troublesome is the left exhaust.. it's either going to be .08mm or .03mm.

Yeah - that's why I recently whined in another thread about wishing we could buy "half sizes" - like the 2.68 you've got!  

Since it was so loose this time I figure it's getting looser so why not stay on the tight end

Conventional wisdom is that loose is better than tight, but your reasoning is sound.  Like you said, check it again in another few thousand and keep track of the trend....  

[scratch]

Keep that 268!

Personally, I'd go with the suggestion Kerry made, with preference towards loose on the exhaust side (.08/270 Left Exhaust, .06/268 Right Exhaust) to avoid a burnt valve and to keep up fuel economy.

[treybrad]

Ok, well you guys are the experts. I'll leave it on the loose end and keep an eye on it until it becomes loose loose again and swap it out for the other shim I bought. Thanks for all the help!

trey

[treybrad]

Oh yeah.. what are the symptoms of being loose? I know w/ tight valves warm up can be a pain (backfiring, stumbling, etc), gas mileage sucks, etc... what about loose? Just the noise?

Reason I ask is b/c I thought I had a few tight symptoms. On warm-up it'll hick-up a bit and give me a few backfires through my lunchbox. Choke doesn't want to work so hot sometimes, I'll have to babysit the throttle a minute to make sure it doesn't die even w/ full-choke on if it's real cold (40 degrees). And, my gas mileage I was really hoping sucked b/c of valves. I get ~40mpg usually.

Any chance my ONE tight intake valve could have something to do w/ that stuff? That's really my only complaints w/ the running of the bike. Once it's warm it runs like a top, even if it does suck gas. I haven't ever really noticed any "rattle/chatter" which is associated w/ loose vavles.

I guess I'm just asking if I'm going to notice any changes or if everything is "close-enough" to where I'm not going to really feel any change.....

trey

[scratch]

Oh yeah.. what are the symptoms of being loose? I know w/ tight valves warm up can be a pain (backfiring, stumbling, etc), gas mileage sucks, etc... what about loose? Just the noise?

The only symtoms that I can think of when running on loose valves is a real hesitation in the motor at high speeds, but that is with really loose valves.

Reason I ask is b/c I thought I had a few tight symptoms. On warm-up it'll hick-up a bit and give me a few backfires through my lunchbox. Choke doesn't want to work so hot sometimes, I'll have to babysit the throttle a minute to make sure it doesn't die even w/ full-choke on if it's real cold (40 degrees). And, my gas mileage I was really hoping sucked b/c of valves. I get ~40mpg usually.

You mean that's not normal with our bikes!?! (Try a little less choke, warm up the bike for no more than 2 minutes, so that you're not using so much gas.)

Any chance my ONE tight intake valve could have something to do w/ that stuff? That's really my only complaints w/ the running of the bike.

Like here?->

Reason I ask is b/c I thought I had a few tight symptoms. On warm-up it'll hick-up a bit and give me a few backfires through my lunchbox.

I guess I'm just asking if I'm going to notice any changes or if everything is "close-enough" to where I'm not going to really feel any change

Post back and tell us.