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Discussion Starter · #1 ·
I recently bought a 06 r6 with 38k in great shape with 2 owners before me, asked the last owner when was the last time he got the valves adjusted and he said he never did so I asked him when he got it how many miles it had when he got it and he said 17k, now my question is the bike runs perfectly fine and occasionally it dies when cold if I touch the throttle but if she is warmed up it runs fine, another question is sometimes when I let off the gas the bike jerks forward a little, the chain seems little loose and he did do the 520 -1front +2 rear conversion so I'm not sure id that has anything to do with it? Thanks
 

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pin it to win it
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Youre about 14k past due.
Tighten the chain to spec and see if it helps.
You want to do a throttle body sync as well and all new fluids
 

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Love my R6 rat bike!
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A chain is better too loose than tight. It should have about 1 1/2-2" of slack.
Definitely right on. I went to Ride Now Motorsports in Las Vegas and the mechanic looked at me like I was an idiot when I told him 1"- 1 1/2" chain slack. I asked him why and he said he's seen so many sprockets chewed up. He was a young guy who thought he knew better, that's the scariest kind.

I believe the manual says 60k before a valve adjustment. The thing to know if you need a valve adjustment is by a very distinguishable ticking sound coming from the motor. Otherwise, you're good. I know a buddy who has 40k on his 09 R6, running good. If its a race bike, then yes it will need adjustment somewhere around 5k and you will definitely hear the ticking sound.
 

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UR B-hind Da 8 Ball
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Valve lash doesn't wear loose. It wears tight as the valve tries to hammer itself into the head. You won't get a tick from valves out of adjustment from normal wear. What will happen is that the bike will start to run poorly at idle when it gets warm (at least in the beginning). If you continue to ignore it, the rough running will get worse until it'll get difficult. or impossible to start.

Valve lash adjustment interval is 26K miles.
 

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Love my R6 rat bike!
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Valve lash doesn't wear loose. It wears tight as the valve tries to hammer itself into the head. You won't get a tick from valves out of adjustment from normal wear. What will happen is that the bike will start to run poorly at idle when it gets warm (at least in the beginning). If you continue to ignore it, the rough running will get worse until it'll get difficult. or impossible to start.

Valve lash adjustment interval is 26K miles.
Are you taking about the wear from the valve seat? I'm looking it up in the manual and trying to figure out what you're talking about.
 

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Pastor of Muppets
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Are you taking about the wear from the valve seat? I'm looking it up in the manual and trying to figure out what you're talking about.
He's saying that as wear occurs, your gap between the bucket and cam will be tighter than spec rather than larger than spec.
 

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UR B-hind Da 8 Ball
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Yes, normal wear on a valve is from the valve spring slamming the valve closed into the seat. Over time, the valve wears a dent into the valve seat (in simple terms). This means the valve stem sits just a little bit higher, and gets closer to the camshaft, so the valve lash gets smaller. The cam lobes don't wear as much, which would be the case to make the valve lash looser during wear, and would result in a "valve tick". But that doesn't typically happen. Generally, valve lash gets tighter over time, so you won't hear a tick. What happens is, when the engine gets to temperature and the valve stem expands from heat it will take up the lash and actually cause the valve to stay open, just a bit, and you start losing compression. As the valve lash gets smaller, the bike will start to idle rough. At first, this symptom will exhibit itself only when the engine gets up to temperature, but it will eventually get worse until the bike is difficult to start.
 

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Love my R6 rat bike!
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Yes, normal wear on a valve is from the valve spring slamming the valve closed into the seat. Over time, the valve wears a dent into the valve seat (in simple terms). This means the valve stem sits just a little bit higher, and gets closer to the camshaft, so the valve lash gets smaller. The cam lobes don't wear as much, which would be the case to make the valve lash looser during wear, and would result in a "valve tick". But that doesn't typically happen. Generally, valve lash gets tighter over time, so you won't hear a tick. What happens is, when the engine gets to temperature and the valve stem expands from heat it will take up the lash and actually cause the valve to stay open, just a bit, and you start losing compression. As the valve lash gets smaller, the bike will start to idle rough. At first, this symptom will exhibit itself only when the engine gets up to temperature, but it will eventually get worse until the bike is difficult to start.
So, how do you prevent it or do you just check the valve seat every 26k, OR when the engines idles rough? When you get a high mileage motor with a rough idle, is that the clear indication that the valves have worn into the head?

Is checking and adjusting the valves as important as valve lashing?
 

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UR B-hind Da 8 Ball
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So, how do you prevent it or do you just check the valve seat every 26k, OR when the engines idles rough? When you get a high mileage motor with a rough idle, is that the clear indication that the valves have worn into the head?

Is checking and adjusting the valves as important as valve lashing?
The only way to prevent it is to not run the bike. That's why is't called "normal wear". You don't adjust the valves, you adjust the valve lash (or clearance between the cam lobe and the bucket that sits on top of the valve stem. That's done every 26K miles. You don't do anything with the valves or valve seats until you do a motor rebuild, or the valve lash adjustment requires too small of a shim to get it in spec....or you have compression issues due to valve damage other than normal wear, such as burnt or bent valves. At that point you need to cut the valve seats, or replace them (and possibly replace the valves), and lap the valves to the seats.
 

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UR B-hind Da 8 Ball
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Like changing the oil, doing the valve tappet clearance is required preventative maintenance. The factory interval for this process is 26K miles.

You might get lucky and never have your clearances change but in all my years of doing valve tappet clearance jobs (YZF1000R, YZF600R, YZFR6) there have always been valves that need their clearance corrected with a shim change.

If you are cheap find a non-dealer motorcycle repair shop and get it done.
:yes

And, loose valves will tick BUT, the typical R6 tick is from the cam chain slapping the chain guides.
How many times have you seen loose valve lash that wasn't due to bent or damaged valves outside of normal wear. I haven't. Yes, it could happen, but usually it is an indication of something more serious.
 

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Yes, normal wear on a valve is from the valve spring slamming the valve closed into the seat. Over time, the valve wears a dent into the valve seat (in simple terms). This means the valve stem sits just a little bit higher, and gets closer to the camshaft, so the valve lash gets smaller. The cam lobes don't wear as much, which would be the case to make the valve lash looser during wear, and would result in a "valve tick". But that doesn't typically happen. Generally, valve lash gets tighter over time, so you won't hear a tick. What happens is, when the engine gets to temperature and the valve stem expands from heat it will take up the lash and actually cause the valve to stay open, just a bit, and you start losing compression. As the valve lash gets smaller, the bike will start to idle rough. At first, this symptom will exhibit itself only when the engine gets up to temperature, but it will eventually get worse until the bike is difficult to start.
Or you BBQ your valves.... whichever comes first, lol :dunce:


I had a buddy down in FL with an F4i with these same scenario..... it wouldn't start and he couldn't figure out why, finally figured out he had a couple valves hanging open cuz they were too tight
 

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Discussion Starter · #13 · (Edited)
Thanks for all the info guys, I did read about the 26k prior to posting I just found it weird how with that many miles it still runs when warm, mainly is when the bike is cold and you give it some gas and it dies, taking the bike to Marrieta Motorsports within the next couple of days when I have some free time.
 

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pin it to win it
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Marietta motorsports will take good care of you. One of the best shops around atl.
 

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UR B-hind Da 8 Ball
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My previous bike (600R) had an exhaust valve that would consistently go loose, several times it worked it's way back up to .012" (EX is .008-.012"). I finally shimmed it so it was at the tight end of the tolerance (.008") and the issue stopped.

Valves can go tight...sinking deeper into the valve seat.
Valves can also get loose...the valve stem gets hammered and the clearance becomes greater.

My opinion: For a quieter/more durable valvetrain don't leave the exhaust valves at the max clearance.
I would suspect that you had something, else, going on there....like a valve guide that was a bit tight, making it so the valve lagged behind the cam profile slightly, and was smacking the cam lobe on closing. Your issue was not typical.
 

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Meh
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I was about to start a new thread on this, but since we're all on the subject - I'm in the midst of checking valve clearance right now and 3/4 of my exhaust valves are borderline too tight. Spec on the 2nd gen exhaust valves is .23 - .3mm and I can get a .229 feeler in there, but not the .254.

Part of me says "well you've got it all apart, might as well finish it up and re-shim them". The other part of me wants to put it back together so I can go ride instead of waiting on parts and pulling camshafts and having more sh1t to reassemble.

What says you guys? FYI, this is my '05 race bike - so it doesn't see a lot of miles, but they're hard ones, and I'd recheck the valves again next off-season (ie, May 2015).
 

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UR B-hind Da 8 Ball
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I used to check valve lash on my race bikes every 2 weekends, and usually didn't have to shim more than 2X a year. But that was on FZR400's which had tiny valves, and revved as high as the R6. I would shim them, personally. Exhaust valves dissipate heat through the valve seat, and if the head of the valve doesn't fully contact the head, the more heat stays in the valve, and can lead to, as Jared put it, BBQ'ed valves.

As I have implied, I set valves on the looser end of the spec, for two reasons:
1. They stay inside spec longer, and
2. I had one of the Vance and Hines mechanics that used to put together Jaimie James and Colin Edwards' FZR600's (dating myself, here) give me the tip that they found that setting the valves on the loose end showed a small, but measurable (< 1 HP) gain on the dyno. I don't know if this gain was something that was specific to the FZR motor, or what, but I figured if it was good for the pink and yellow bikes, it would be good for my little club level Fizzer.
 

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Meh
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I used to check valve lash on my race bikes every 2 weekends, and usually didn't have to shim more than 2X a year. But that was on FZR400's which had tiny valves, and revved as high as the R6. I would shim them, personally. Exhaust valves dissipate heat through the valve seat, and if the head of the valve doesn't fully contact the head, the more heat stays in the valve, and can lead to, as Jared put it, BBQ'ed valves.

As I have implied, I set valves on the looser end of the spec, for two reasons:
1. They stay inside spec longer, and
2. I had one of the Vance and Hines mechanics that used to put together Jaimie James and Colin Edwards' FZR600's (dating myself, here) give me the tip that they found that setting the valves on the loose end showed a small, but measurable (< 1 HP) gain on the dyno. I don't know if this gain was something that was specific to the FZR motor, or what, but I figured if it was good for the pink and yellow bikes, it would be good for my little club level Fizzer.
Yeah, that's the way I was leaning. I just want to get some damn track time in though! :) This is my first time doing the valves, so taking it slowly and working on it when I've got time. Have had the bike in the garage torn apart for good 3-4 weekends already and I'm getting track-time withdrawal.

I did a fair amount of searching previously about adjusting valves and power output, and came upon a bunch of different theories. Some say set them tight, some say loose, some say set one loose and one tight, or intake loose and exhaust tight, etc. etc. The only consensus seemed to be that whatever gains they got were fairly minimal. :laugh

The first point about staying in spec longer is a good one though.
 

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Love my R6 rat bike!
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Yes, normal wear on a valve is from the valve spring slamming the valve closed into the seat. Over time, the valve wears a dent into the valve seat (in simple terms). This means the valve stem sits just a little bit higher, and gets closer to the camshaft, so the valve lash gets smaller. The cam lobes don't wear as much, which would be the case to make the valve lash looser during wear, and would result in a "valve tick". But that doesn't typically happen. Generally, valve lash gets tighter over time, so you won't hear a tick. What happens is, when the engine gets to temperature and the valve stem expands from heat it will take up the lash and actually cause the valve to stay open, just a bit, and you start losing compression. As the valve lash gets smaller, the bike will start to idle rough. At first, this symptom will exhibit itself only when the engine gets up to temperature, but it will eventually get worse until the bike is difficult to start.

So I'm still a little bit confused and I'm honestly trying to understand this. Is valve lashing that you're talking about the same as checking the valve clearances between the bucket and cam lobes? Because if it is, I do it every year. I did have an R6 race bike with 16k (mostly street miles) and it did have a ticking sound. I checked and found the clearances between the bucket and cam was smaller than spec, so I re-shimmed it and brought it back into spec. Ticking went away. So the valve lashing, is this another maintenance that I'm not aware of? Do I have to take the valve out of the motor and check them with calipers, or check the seal of the valve in the head? Is there any other maintenance needed to be done on the motor other than changing the oil, syncing the carbs, and checking the valves?
 

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UR B-hind Da 8 Ball
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Valve lash and valve clearance are the same thing. You don't have do do anything else with the valves until you rebuild the motor. You're good.


I would bet that the ticking you heard was from the cam chain tensioner. It expands slowly over time to take up slack in the cam chain so it probably hadn't expanded to the next notch because it hadn't overcome the friction. When you reinstalled it, it set itself tighter when it snapped into place. Just a guess...albeit an educated one.
 
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