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I just did the valve check on my bike at tech day and all was good. I recently rode Viper Dad's bike and immediately said "WOW...something is not right with this". Doesn't run smooth at all, to me.

It got me wondering, since his bike has about 80,000 miles and it's been several years since I checked them. It's making me wonder if his valve clearances are out, and that's causing it to run rough.

So what symptoms would one expect to see as valves go out of adjustment, from minor to major?

Festus wrote: ↑Sat Aug 06, 2022 1:34 pm I just did the valve check on my bike at tech day and all was good. I recently rode Viper Dad's bike and immediately said "WOW...something is not right with this". Doesn't run smooth at all, to me.

It got me wondering, since his bike has about 80,000 miles and it's been several years since I checked them. It's making me wonder if his valve clearances are out, and that's causing it to run rough.

So what symptoms would one expect to see as valves go out of adjustment, from minor to major?

You probably wouldn't know unless it was WAY off and that isn't going to happen in a few tens of thousands of miles. Valves generally get tighter (and quieter) as they wear. Now, if there was a valve spring problem...? He has been chasing issues for a while. By this point, I would probably have looked for a new engine!

Usually hard starting

I just did a valve check on an '03 with 56k kms (35k) and it has a problem with obvious miss on more than one cylinder.... it had 4 intakes at minimum and 3 just under.... fixing it did not solve the problem. A few years ago we had an '05 that had an idling problem, valve check revealed one valve that had zero clearance and we suspect it was holding the valve open... never saw one of those before or since.... repaired that, idle improved and apparently got better with more mileage.

I doubt the bike's valve clearances are a problem..... a compression check might confirm that.

raYzerman wrote: ↑Sat Aug 06, 2022 2:29 pm I just did a valve check on an '03 with 56k kms (35k) and it has a problem with obvious miss on more than one cylinder.... it had 4 intakes at minimum and 3 just under.... fixing it did not solve the problem. A few years ago we had an '05 that had an idling problem, valve check revealed one valve that had zero clearance and we suspect it was holding the valve open... never saw one of those before or since.... repaired that, idle improved and apparently got better with more mileage.

I doubt the bike's valve clearances are a problem..... a compression check might confirm that.

Yeah, that's on the list of things to do, just don't get to spend much time around the bike these days and would rather ride it than work on it

When you get a chance hit me up and we can set up a time to do the clearance and compression check.

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Intech wrote: ↑Sat Aug 06, 2022 3:02 pm When you get a chance hit me up and we can set up a time to do the clearance and compression check.

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Thanks Bob, I'll let Viper Dad know. We need to get this thing running right again. I was not happy when I rode it. Can't believe it's running like that. Plus the tires appear to be out of balance. At higher speeds, a vibration came in that was quite unsettling. I have the balancer so I'll try to check that soon. I think he's really busy so I'll put the info out to him and let him start trying to make a day for it.

The first symptom of tight valves is hard cold starting. The valves are so tight they don't seal, making it hard to start. When engine warms the valve lash might open a bit making subsequent hot starts relatively easier. But by this time damage is being done. When the valve can not seat solidly it can not conduct heat into the cylinder head. Valve continues to get hot and hotter until it burns.

If the bike only has 80,000 miles and it has had at least one valve check at the prescribed mileage (so we know it wasn't bad from the factory), I can't imagine that it is off enough to cause noticeable operating problems. They just don't change that quickly. Unless valves aren't closing because of carbon buildup or a valve spring is bad...

Definitely worth the valve check and compression testing. Seems to me the compression check was one of the items suggested some time ago. I would REALLY like to know what's wrong with this engine.

(Did you ever try the tank swap again?)

Have the throttle bodies ever been synced or even checked? Is there a missing or torn rubber cap?

After compression and leak down check, I'd do a T/B sync, replace the plugs, and run a can of seafoam through it.

FJRoss wrote: ↑Sat Aug 06, 2022 4:29 pm Definitely worth the valve check and compression testing. Seems to me the compression check was one of the items suggested some time ago. I would REALLY like to know what's wrong with this engine.

(Did you ever try the tank swap again?)

Haven't worked on it any more in a while. Viper Dad got a promotion so he's swamped and I've been working 100 hour weeks. Finally got a break yesterday and we pointed them towards the mountains and twisted the throttles. Both of us back to work today.

Throttle bodies have been synched, but we'll check it again. I'm telling you, it's running rough. He was thinking it's running normal until he rode my bike and I rode his. We both came away shocked. I said "What the heck is that vibration about 100?" and he said "Oh, that's been there for a while, it feels like the bike it coming apart".

Me : "Yeah, that's not normal".

Wheel bearing? Motor mount?

What have you been using for an injector cleaner in your cleaning machine? Does it have benzene or zylene in it? Injectors are clean, yes?
I can't get a handle on the severity of this "vibration". Especially if it doesn't show until 100... a better description please........

Your sync won't be out much I'm betting, but if it is that would be good to know.... it's not causing the issue at 100.

Valve clearances IMHO would have to be pretty darn tight to have much effect on this......

I’m not sure Ray, that was a couple months ago. I’ll check and report back.

Here’s the sequence of events...

Ate lunch, came out and offered to swap bikes so he could try out my Stompgrip’s on my tank.

I started his bike and it immediately felt like it was running rough to me. Not a smooth idle. We pulled out and he immediately commented on how smooth and tight my bike was, within a block.

We rode a mountain pass and probably 30 miles. During that, there may have been a high speed pass or two. During that, I just felt the bike vibrating excessively in the high 90’s. At normal speeds, I could feel a buzzing in the seat.

I attributed the vibration to the front wheel being out of balance. Maybe I’m wrong.

I just know something or things is wrong with her. I’ve never ridden a bike that rode like that. He said it’s normal and has been like that. I know it wasn’t like that years ago so it’s gotten progressively worse, slow enough that he’s gotten accustomed to it.

It pulls and accelerates perfectly normal.

Check wheel bearings and motor mount torque as per FJRPittsburgh, above.
TBS isn't going to be an issue much above idle.
Do the valve clearance and compression/leakdown.
No starting issues?
No power issues? (I see you just answered that)
Normal fuel consumption?
Have a look at u-joint and check that the rear drive isn't getting hotter than normal.

What would a broken or weak valve spring do?

T/B sync-check
Verify no rats nest or "other" in the air box. Blow out the air filter.
Check for ECU codes
Make sure plug wires are on tight. Check coil grounds. New spark plugs (or at least pull them and see if one or more looks different)
Re-torque motor mount bolts in accordance with the manual
Can of seafoam in a tank of gas with techron in it.

Then ride the snot out of it - hard throttle, higher rpm shifts - get the motor hot.

Then re-group.

No starting issues, normal fuel consumption.

Air box is clean. Just had it out myself, brand new air filter. New plugs, I just checked the gaps on them all not long ago, swapped the coils from my bike to it, problem is still the same, still runs rough at idle.

He runs seafoam in it from time to time. Also just ran a can of intake valve cleaner through it last month. Oh, it gets ridden at high RPM's, so that's not an issue

Check to the plugs/nipples that cover the throttle body sync ports. If one is missing or cracked, could be contributing to it.

Sounds like you need to bring it to Geeks tech day so we can let the smoke out of it and he can pick up a new ride at Iron Pony in Columbus...

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