Is premature valve wear associated with premature detonation?

I came across a very interesting thread:

http://www.thumpertalk.com/forum/showthread.php?t=175589

Please take time to look it over (it is only two pages long/very short for a fuel debate if you ask me :confused:) as I need some guidance before I jump to rash conclusions and hypothetical nonsense. The thread entails various points of views and methodical approaches as to octane boosters and other variants of fuel mixtures and after three and a half years, of trying various methods of slowing down premature valve wear, I wanted to take a closer look at the possibility of fuels being mislabeled at the pumps at gas stations possibly being the culprit. I'm not looking for more power, I'm looking for a cause other than a dirty air filter or hitting, not riding the limiter which I don't have or do either of the two. I have tried in vain to isolate a definite cause, because my filter is cleaned before every ride and every possible avenue you could think of, I have probably tried. I'm talking about slowing down the first adjustment that is made to the valves. After the first adjustment, I'm planning on running them until they reach the second adjustment and then replace them. I'm not going to run below a certain shim size anymore. Back to my point though - The first adjustment should be the one that takes the longest to get to because of the thin protective coating on the stock Titanium valve face. Over time that wears off and the valves gradually wear progressively faster and faster. I run my valves about mid-specs and some guys run them on the tighter side of tolerances and some on the loose side of tolerances and I pick about the middle of the road: (Intakes I set at .125 and the Exhausts I set at .195 - Does that possibly have any bearing on how fast the valve will wear before the protective coating is even gone? I would think not, because I have tried both ends of specs (tight/loose) with no results :thumbsup: I know that I would probably need to shim before most guys running on the loose end of spec (wide lobe to bucket clearance); but my concern is over delaying reaching that first crucial shim adjustment and am interested in any ideas that fuel lower than 94 (I run 94) may cause premature valve wear. I'm specifically concerned over whether or not premature detonation would cause this and if so, I guess I would have to buy a hand held fuel analyzer and make big gas stations buy my next top end for mislabeling fuel at the pumps yet alone ripping me off for three years selling regular pump gas at premium prices. I'm out of options here guys and the fuel is the last thing I can think of that might cause this. Don't get me wrong, I'm pulling 200 hours out of valves with no problems; but, that is with five adjustments or more. When I heard that those hours can be achieved with just one adjustment on the valves, A BIG RED FLAG WENT UP - I'm just tired of my bike being an experiment to the next batch of mislabeled fuel, if indeed anyone can confirm that premature detonation from a mislabeled octane rating could cause this issue. Sorry, there is just no short way to ask what I'm getting at, and I have known you guys to be patient with my questions before. After all the time I spent reading numerous threads, the one that I mentioned above, is the only possibility I haven't considered. Is that thread leading my inclination astray?

I thought if the octane was wrong, that the bike would just have trouble running correctly and never considered maybe that premature valve wear through premature detonation could be associated with it. Yet, is it possible to have the wrong octane and the bike run slightly different but not enough to affect power yet rob valves of their first initial adjustment life expectancy?

Thanks:thumbsup:

Edited by nokickstandsallowed

I have a very bad short term memory so please forgive me if you had mentioned this before in another thread. Are all of these problems you are having on the same original head? I know you've gone thru different sets of valves and seats but were the guides ever replaced? This is what might be happening and again I'm sorry if it pIsses you off more but the guides might possibly not be bored straight therefore valves are slamming into the seat at a bad angle. Valve springs too strong? I know in car engines pre-detonation will wipe out the piston long before the valves. I know running unleaded gas in old cars is bad for the valves and seats but that hasn't been a problem since the 60s. How many times have you replaced the valves in this head? If it has been multiple times you might want to have Jesse William or Ron the resident engine expert take a look at it and see if they can find a reason why it's eating valves or maybe find a cheap used head on eBay and maybe have it sent out to an expert to be rebuilt. Again I apologize if you went over any of this before

I have a very bad short term memory so please forgive me if you had mentioned this before in another thread. Are all of these problems you are having on the same original head? I know you've gone thru different sets of valves and seats but were the guides ever replaced? This is what might be happening and again I'm sorry if it pIsses you off more but the guides might possibly not be bored straight therefore valves are slamming into the seat at a bad angle. Valve springs too strong? I know in car engines pre-detonation will wipe out the piston long before the valves. I know running unleaded gas in old cars is bad for the valves and seats but that hasn't been a problem since the 60s. How many times have you replaced the valves in this head? If it has been multiple times you might want to have Jesse William or Ron the resident engine expert take a look at it and see if they can find a reason why it's eating valves or maybe find a cheap used head on eBay and maybe have it sent out to an expert to be rebuilt. Again I apologize if you went over any of this before

No need for apologies. Over the course of three and a half years, all three heads were brand new as was the entire valve train. Something was wrong with two of them because of collateral damages from two minor events and the third one ate it because of a faulty valve and cam chain. All stock parts also. Do you know of any recalls on pre-assembled heads that I may have missed in the last three and a half years because of poor installation of the guides which are already inserted in pre-assembled heads? If there was, I didn't get that memo, but I can assure you that someone will get mine if that's the case. When I ordered a head, I got one with the valves already in it for $795 and two of them just had the guides, and cam caps without the valves for like $400 for each one. The one that I am getting for my rebuild now, has the valves already installed and therefore leading to my questions. I need to make absolutely sure that if pre-assembled heads need checked for accuracy, then why the hell am I being charged for pre-assembled labor in the cost of the head? In other words, why should I have to check anything other than the valves sealing properly if I am paying the cost of having them (valves) pre-installed correctly? I forgot to mention a good point you made. When I got a head without the valves installed (twice), I always reamed the valve guide to ensure proper stem-to-guide clearance, which they were usually pretty close. Furthermore, I'm thinking what are the chances that the whole damn guide could be cocked in the head or free roaming a little which in turn would not allow for the valve to seat properly or concentric all of the time but maybe only part of the time? That is where I felt that something maybe could be wrong; therefore, leading to my question of a possible recall.

Edited by nokickstandsallowed

I have not heard of any recalls on guides. The only recall I've heard of are the valves on 06s and that has been covered. So to recap you've gone thru three heads already but one of them was because of faulty parts and/or workmanship the other two because of some other damage. Is this correct? If it is, it sounds like you have some f--ked up luck with heads man!! You have to adjust your valves way too much and too soon on all of the heads, correct? What is the history of the cams that are being used in all of the heads?

You know what? PM Ron Hamp and see if he has heard of this and see if he has any input

I have not heard of any recalls on guides. The only recall I've heard of are the valves on 06s and that has been covered. So to recap you've gone thru three heads already but one of them was because of faulty parts and/or workmanship the other two because of some other damage. Is this correct? If it is, it sounds like you have some f--ked up luck with heads man!! You have to adjust your valves way too much and too soon on all of the heads, correct? What is the history of the cams that are being used in all of the heads?

Hmm, the history of the cams can be best summed up by the fact that they were never the cause of any of the problems nor were they damaged by any collateral events except this one recently- but, will be replaced this time around. I once had the lobes checked by a shop and they stated specifically that entry face angles were precise as well as the departure degree angles or whatever unique analytical terms they gave me about the measurements taken on them as they interface the buckets. See, that is why I want to know if fuel is the cause of all this, because no one gets three bad heads in a row - no one, not even me. :thumbsup:

Go to a different gas station

You know what? PM Ron Hamp and see if he has heard of this and see if he has any input

That is a suggestion that I have not pursued yet, and will probably end up taking if it is true that you can get 100+ hours out of valves before the first adjustment is needed. I need to isolate a root cause of premature valve wear, because I already know what the f:foul:ing symptoms are, as well as the results.

Edited by nokickstandsallowed
Go to a different gas station

I have tried various stations and ended up staying with one that I semi-trust.

If fuel is the cause of this fiasco, I can nail it down to one station, since I am a frequent visitor. I filter my fuel also - did I mention that? Not only is the fuel filtered at my gas can, but is filtered at a junction in my line as well as the screen at the fuel cock.

Kick,

The thing that ruins the valves is FOD going thru them.... ie dirt. You stop that with a smart application of air filtration. The only combo I've used with success is what I call the tripple threat... I use a TwinAir backed up with a Flo on top of that. That's right, a tripple filter. And I make sure I use a sticky filter oil on them... Belray... and I use the filter grease on the seal surface. Valves are $53 each and its trouble to replace them not to mention expensive. You're in Tennessee, so I'm sure in the fall you see really dusty days like we do down here in Alabama. This system works well for me.

Detonation is what you get after you have premature ignition. Its the explosion of the charge before the ignition system fires. It can occure after ignition and you get 2 wave fronts moving thru the combustion chamber.

I have never experienced it with my bikes, and I have 3 YZ250Fs. The design of the head is excellent and aids in eliminating the problem. If yours is detonating, someone's changed something from stock, or your carb needs cleaned out.

Kick,

The thing that ruins the valves is FOD going thru them.... ie dirt. You stop that with a smart application of air filtration. The only combo I've used with success is what I call the tripple threat... I use a TwinAir backed up with a Flo on top of that. That's right, a tripple filter. And I make sure I use a sticky filter oil on them... Belray... and I use the filter grease on the seal surface. Valves are $53 each and its trouble to replace them not to mention expensive. You're in Tennessee, so I'm sure in the fall you see really dusty days like we do down here in Alabama. This system works well for me.

Detonation is what you get after you have premature ignition. Its the explosion of the charge before the ignition system fires. It can occure after ignition and you get 2 wave fronts moving thru the combustion chamber.

I have never experienced it with my bikes, and I have 3 YZ250Fs. The design of the head is excellent and aids in eliminating the problem. If yours is detonating, someone's changed something from stock, or your carb needs cleaned out.

Thank you good Sir. If I use a triple threat filtration system, my jetting days are going to get really interesting. I already run a double system in the box as well as at the two inlets below the seat. How much more can I suffocate this bike before telling it to run on just gas? Realistically, you're right about the dusty conditions; however, I don't honestly know how much more I can filter the air before the bike would literally act like it is drowning in water. Am I going to have to get this bike an oxygen tank? :confused:

Thank you again Ron, you have always been helpful and spot on. I'm just wondering also, if the octane is wrong and the bike doesn't care, what percentage of valve wear could be associated with that issue. I know octane being wrong destroys pistons and rings, but our valves aren't protected by such a serious thing as a thick cylinder sleeve and they are more exposed riding up and down with such a thin stem. Everything is always brand new stock when I replaced my top ends. Do you mean to imply that original oem stock parts from distributors are being swapped out with look-a-likes and copycats? I sure hope not, because that is the only way something would be changed from stock on my bike. Unless I started sleep-walking and doing maintenance on my bike. :thumbsup:

P.S. - I like the FOD acronym you used, because I use to make sure that loose objects weren't around turbines that run at greater RPM's than our bikes and would suck a whole body up faster than a tree limb chipper, which I actually saw a guy helped into one down in Florida - a wood chipper and a turbine - not a pretty site on either, especially when you have to prove you aren't the one that pushed/helped somebody into those objects.

Around this neck of the woods, it stands for Frequently Opened Drinks.

EDIT: I forgot to mention, I even have that little circular hole on the bottom of the air box that drains excess water if it gets in there, filtering air coming into the air box also. Everyone always overlooks that one, especially when they are anal about filtering their breather tubes on the carburetor also. I used silicone around where the rubber boot is mated to the air box, just in case anything was trying to sneak through there also, even though it didn't seem feasible to me that doing that was necessary. The triple threat system is my last option other than the non-direct triple threat system I already have implemented.

Edited by nokickstandsallowed

Hey kick, what did you do in the military? You can always rig up one of those hepa filters you see on tv for allergies and stuff, maybe an ozonenator?

Yes I was kidding about the filter

Hey kick, what did you do in the military? You can always rig up one of those hepa filters you see on tv for allergies and stuff, maybe an ozonenator?

Oh, I wandered around aimlessly on ships making sure everyone was safe.

Edited by nokickstandsallowed
Improper grammar usage.

Hey Kick, Yes I did the bottom vent mod too. It was pretty obvious when mud was in the bottom of the air box that something was needed to stop that.

I was just thinking you are worried about something when you don't really need to be concerned. Unless the bike is pinging like mad, its OK, and you have not described how the motor is running.

If it will crank and run hot or cold, and pull, you're good to go. Think about this: if this motor was scaled up to equal a 5.0 Ford, it would be putting out about 430hp, which is really stout. So it is a high output small powerplant. Run it in the rpm range where its producing power, between 5,000 rpm and 10,000 rpm.

Supplies are not swapping parts out. If you look at the air filter, you can actually see thru some brands. If you can see thru it, dirt can come thru too. I just decided I'd do something in addition and see what effect it had on reliabiity. It help! And no I didn't have to re-jet my bike, just adjusted the fuel screw! That was it. Good luck and enjoy your ride.

I was just thinking you are worried about something when you don't really need to be concerned. Unless the bike is pinging like mad, its OK, and you have not described how the motor is running.

I was just listening to some videos on YouTube of four strokes that have excessive ping from incorrect octane levels. It sounds like a motor running inside another motor at the same time. Meaning, they were putting to a test, regular versus premium pump gas and the difference between the sound the bike puts out on each of the two fuels. I am not one bit happy with the results I heard. No matter how I adjusted the equalizer, the sound of the bike running on the two different fuels is so obvious that only someone that doesn't know the difference between a smoker and a four stroke would be the ones to miss it. I know the difference between the two types of motors; but, the difference between the sounds of the different fuels, I did not know how to listen for. I am just going to buy the hand held fuel octane analyzer for $200 and mix in an octane booster until the correct octane reading is achieved. I obviously can't trust the gas stations to have their fuel labeled correctly, or they are trying to pull a fast one and they haven't got caught yet. The bike, when it is running, is great for stock since I have had the opportunity to compare it to other rides from different base jetting platforms offered by some friends that have previous and later models. The only thing I have been told by fellow riders that I ride with, is that my exhaust smells as if my fuel is not being completely burned off. A wet, rich smell, is the best way they could describe it. I'm thinking at this point, I just need to repack the silencer since that has not been done since the dark ages - and roll this all up, and hang it around my neck and try it again.

Edited by nokickstandsallowed

Yeah, you hit on something there, muffler packing makes a huge difference in performance. I tend to let mine go too long also, and my hearing is taking a beating for it.

Just be aware that adding octain booster will make it harder to start your engine, and can foul your plug. I tried it years ago and decided against it. Also, fuel companies change their fuel blend from winter to summer blend. The difference is in the additives, what I call the airomatics, or the parts that will boil off or evaporate out of the fuel.

One last thing, the stuff is dangerous to handle and can cause multiple health issues. From my perspective, its not worth it. Its much easier to find a source of race gas if you must have it. But its not necessary for a stock engine. It smells cool in the exhaust, but at $6.00 a gal, just too expensive.

Yeah, you hit on something there, muffler packing makes a huge difference in performance. I tend to let mine go too long also, and my hearing is taking a beating for it.

Just be aware that adding octain booster will make it harder to start your engine, and can foul your plug. I tried it years ago and decided against it. Also, fuel companies change their fuel blend from winter to summer blend. The difference is in the additives, what I call the airomatics, or the parts that will boil off or evaporate out of the fuel.

One last thing, the stuff is dangerous to handle and can cause multiple health issues. From my perspective, its not worth it. Its much easier to find a source of race gas if you must have it. But its not necessary for a stock engine. It smells cool in the exhaust, but at $6.00 a gal, just too expensive.

I made a mistake by stating that my intentions were to add an octane booster in a previous post. I meant to suggest that I am going to be more careful in how I approach my fuel choices and filtration. The analyzer that I have my mind set on is one that I have used before, but passed up buying and regret it.

It is the ZX-101C PORTABLE OCTANE ANALYZER. I am almost positive that if I purchase this and am able to keep a consistent number in my fuels octane level, I can eliminate that as a possibility adding to my $1200 a year tab on most top ends gone through by a TT member for a bike that is only going to be four years old this June. Either that, or I am really going to start questioning the integrity of the parts I am receiving, because it sure in the hell isn't my riding style that is causing these premature situations to occur. I couldn't ride the bike any easier and nice than what I am, and if I ride it any nicer, I might as well get it a side cart and tote people around the neighborhood. I bought it brand new June 7th, 2007. If there is one thing that I have learned from previous training, numbers that remain consistent either produce results or eliminate possible culprits to failures.

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