Big SHOUT OUT to Yamaha

[SkooterG]

Beyond what Jestal may say, I have been dealing with stem seals and valve guides in car engines. I started building engines and tweaking them when breaker point ignition and carbs was all there was. One of the things that would help polish an engine for the last bit of power was to address the stem guides and seals, usually with something like Perfect Circle products. I have clearanced guides so that the stem seals would stay clear of valve keepers and springs as well as accepting a little oil consumption to keep oil on the valve stems. With the leaded gas at the time it was common to have wads of coked oil down by the flute of the exhaust valve. In the case of the FJR I would consider lubrication as a plausible and likely explanation. The trace film of oil placed on the valve stem due to the planned seal bypass is so thin, as in real, real thin that I don't see how that could impart any cooling except by reducing friction in the guide which is what the extra bit of oil seal bypass was supposed to do. If the stem seal gets any looser than this the engine begins to become an oil eater and you will be adding oil and your FJR would fail emission inspection should it be required.
IMO, the root fix for the FJR ticking is extra lubrication to reduce friction and wear, a secondary and perhaps incidental byproduct may be slightly reduced temperature due to better lubrication reducing friction.

Since I am All Knowing and Powerful, I am going to go with you on this one.

 

[Ignacio]

Oh, gawd, please make it stoooooooooooooooooooooooooooooooooooop.

What? Your inane, moronic posts?

I would be more than happy to do that.

I'd back you up with a second batch of mouse clicks if needed.

 

[petey]

My ticker was fixed under almost exactly the same circumstances.
I believe the key factor in Yamaha's decision for the goodwill warranty work is if the ticking was documented but not repaired while the bike was under warranty. This sounds exactly like what happened with yours, as well as mine.

Regardless, that kind of goodwill goes a long way towards keeping me a lifelong customer.

I like a good ending...+1 what Bungie said

 

[MCRIDER007]

Beyond what Jestal may say, I have been dealing with stem seals and valve guides in car engines. I started building engines and tweaking them when breaker point ignition and carbs was all there was. One of the things that would help polish an engine for the last bit of power was to address the stem guides and seals, usually with something like Perfect Circle products. I have clearanced guides so that the stem seals would stay clear of valve keepers and springs as well as accepting a little oil consumption to keep oil on the valve stems. With the leaded gas at the time it was common to have wads of coked oil down by the flute of the exhaust valve. In the case of the FJR I would consider lubrication as a plausible and likely explanation. The trace film of oil placed on the valve stem due to the planned seal bypass is so thin, as in real, real thin that I don't see how that could impart any cooling except by reducing friction in the guide which is what the extra bit of oil seal bypass was supposed to do. If the stem seal gets any looser than this the engine begins to become an oil eater and you will be adding oil and your FJR would fail emission inspection should it be required.
IMO, the root fix for the FJR ticking is extra lubrication to reduce friction and wear, a secondary and perhaps incidental byproduct may be slightly reduced temperature due to better lubrication reducing friction.

Since I am All Knowing and Powerful, I am going to go with you on this one.

I am not going to argue with someone ALL Knowing and Powerful. After an hour of reading very old threads about the tick, I found this post from Jestal in response to a question of why the valve guide problem was usually on the left side of the engine.

Posted 20 February 2006 - 05:17 PM

Intake valve stems rarely, if ever, cause a problem. They run far far cooler and there is vacuum on the intake port side of the guide always trying to pull some oil down the guide. Even a "dry" valve stem seal will allow a lot more oil down the intake as compared to the exhaust. There is no steady vacuum in the exhaust port, rather an overlying higher pressure from backpressure in the system so oil does not naturely tend to flow down the exhaust valve guide as with the intake. Plus, the exhaust valves run far far hotter as you would expect.

It is very common for many engines to run distinctly different valve stem seals on the intake and exhaust as well as distinctly different valve guides and valve stem surface treatment. Most all engines have chrome plated exhaust valve stems for scuffing resistence while intakes will be plain or just chrome flashed. I a lot of cases you can run exhaust valve guides with little or no seals due to the lack of vacuum in the port constantly sucking oil down the guide. An intake guide with no seal would be constant blue smoke.

The heat causes several problems. First, it tends to vaporize any oil that is there reducing what little lubricating properties it has. Secondly, it caused the exhaust valve stem to expand more, reducing clearance in the guide. This alone can lead to scuffing if the cold build clearances are not correct. Third, the exhaust valve guide itself runs hotter as well as the parent material it is pressed into. This may be the most important thing, here. The Exhaust valve guide projects slightly into the exhaust port so one end of the guide is running a lot hotter than the other. This cause uneven expansion of the guide and the parent metal surrounding the guide. Uneven expansion means that the valve guide, which is ideally a perfect column, becomes somewhat "banana shaped" to exagerate. The banana shape of the guide when hot ditates the clearance requirements so that the guide will never bind on the stem even when it is hot.

Possibly the left side guides run a little cooler than the right side due to coolant flow patterns thru the head??? Maybe there is some influence of the oil flow inside the head causing a slight temperature gradient across the head as measured at the valve guides. There is always the possibility that the left cylinders run a little leaner than the right cylinders. The O2 sensor measures the sum output of all the cylinders. Some individual cylinders may be a little leaner than others. The O2 and closed loop software just make sure that the OVERALL output of the engine is 14.7:1. Not that any cylinder is likely to be way lean at all but that the left ones might be a few tenths of an air fuel ratio leaner than the right. This would cause a few hundred degrees difference in EGT thus changing the relative distortion of the exhaust guides across the engine....thus causing more wear where the distortion is worst....as you go across the engine to the right side.

Hard to do more than toss out ideas here without a dyno and some measurements and data. A thermocouple in each cylinder would provide a clue if someone wanted to drill their pipes and stick a 4 cylinder EGT system on and do some riding. You would be looking for consistent EGR differences...not a dramatic high or low (lean or rich) pattern.

I have seen situations like that with port fuel systems. Depending on the airbox, the left cylinders may flow more air than the right possibly causing them to be a little leaner for any given pulse width. The location of the fuel pressure regulator on the fuel rail can impact actual fuel delivery thru each injector due to the pressure hammer effect (water hammer) when each injector closes. The pressure pulse can travel to other injectors affecting the amount of fuel they deliver. This can cause distinct rich/lean patterns across a fuel rail. One assumes the engine designer covered this during development.

Injectors are randomly assumed to be plus/minus 3 % for fuel flow rate....so unless the injectors are flowed and matched you can expect a 6 percent range in fuel delivery across the injectors. This would be really rare as generally the injectors are much closer than this and are either all rich or lean....and then the closed loop system corrects for the engine as a whole and there is very little difference between cylinders. The injector effect doesn't explain the left to right issue as the injector issue would be more random.

Just some ideas and things that I have observed. The whole situation with the FJR is not too hard to explain, actually, from an engine development standpoint. They may run a little low on clearance in the exhaust guides (production tolerances) and maybe someone forgot to adequately prelube the valve stems at assembly starting the snowball. Then one side of the head distorts a little more than the other due to some of the reasons mentioned..... Then the valve stem seal supplier retools the seal a little "dryer" by accident thus limiting the amount of oil down the guide that would tend to cover up some of the other issues.

Once again, pure speculation, but it fits my preconceived notions of what could cause the results observed. It is probably not just one thing but an unfortunate combination of circumstances.

He also said in numerous other posts that he thought inadequate valve stem lubrication was probably causing the excessive heat buildup on some stems leading to a ticker and that oil flowing past the seal to lubricate the stems should not be necessary if the stem was properly pre-lubed during the assembly process....but a redesigned seal to provide more oil flow to the stems should solve any lubrication issues.

 

[escapefjrtist]

Whatever the reason, glad Yamaha stepped up to help out with parts.

Congrats!

--G

 

[HotRodZilla]

Yeah...What Escapefjrtist said. They easily could have washed their hands of this and they didn't. That's nice to see!!

 

[art miller]

This speaks volumes for Yamaha. Your testament and all who read it will reward Yamaha many times over.

 

[odot]

Oh, gawd, please make it stoooooooooooooooooooooooooooooooooooop.

What? Your inane, moronic posts?

I would be more than happy to do that.

I'd back you up with a second batch of mouse clicks if needed.

Can you bring me back to under 5000 posts? I want to relive that moment one more time.

"memorieeeeeeeeeeeeeeeeees..................."

 

[Jack D]

Regarding the valve stem seal blocking or metering oil controversy

https://www.skf.com/files/867381.pdf

You can also research other seal manufacturers such as Federal Mogul and Perfect Circle. Valve stem seals are designed to meter the oil.

 

[MCRIDER007]

Regarding the valve stem seal blocking or metering oil controversyhttps://www.skf.com/files/867381.pdf

You can also research other seal manufacturers such as Federal Mogul and Perfect Circle. Valve stem seals are designed to meter the oil.

Good information, my statement that the valve stem seals are not supposed to flow oil obviously is incorrect but I still think the root cause was something other than the seals. Less than 2 percent of the 03-05 FJRs were tickers and those that were tickers almost always had the bad valve guides on the left side of the engine, usually the number 1 cylinder. If the seals had been the root cause then you would also expect to find the problem equally distributed across all 4 cylinders. At this point it really doesn't matter what the root cause was, the solution has been very effective.