Dirty Throttlebody Butterflies

[MajBach]

"Premium" gas is not more refined at all. It just has a composition that is more resistant to detonation. This is an issue in high-performance high compression engines but not in the FJR. Compression ratio is not high enough to require premium grades.

I don't know about other areas, but around here, premium is not supposed to contain ethanol. Mid-grade is supposed to be 5%. I am currently running regular but have considered a switch - just to avoid the ethanol. Of course, you have to take their word for the absence of ethanol in premium unless you want to have it analyzed. Running alky-free gas might improve economy to partially offset the cost but don't expect power gains or cleaner running.

Ross

Since the thread kinda went in this direction, I did a little research on the matter. I always knew that using higher octane when your vehicle didn't call for it was a waste, but I did believe the higher test was 'more refined', i.e. better additives etc. Appears that is not the case for the most part. My link It does state that premium Canadian fuels don't contain ethanol though.

 

[LAF]

SO anyone with the PAIR removed have this issue?

IMHO this is not a gas issue even a little.

Cam lobes are controlling valve openings and valve overlap.

Reversion from exhaust may contribute to this but with the limited options of just cans with the exception of Muzzy or other strait through cant see that as the issue either.

This is IMHO a PCV or in our case PAIR problem. I have had the pair removed since new but have not got to take the boots off to check the TB.

Anyone with the PAIR removed see this issue?

 

[Fred W]

Anyone with the PAIR removed see this issue?

The problem with this is that most of us that removed the PAIR waited until the warranty was over before doing so. In some (many?) cases that was up to 5 years with the YES. So, be forewarned that the data pool is polluted.

 

[RadioHowie]

You know...I'm really liking this serious technical discussion without someone saying "jes sayin and enuf said"...but can't we take a commercial break with some girlie photos?...with throttle bodies in the foreground of course.

Also would like to add, that it wouldn't matter what octane gas you ran in your FJR in relation to keeping the TB butterflies clean. The injector inlets are downstream of the butteflies. Gas of ANY octane never touches the butterflies, so octane or supplemental additives like Seafoam aren't gonna impact the butterflies.

The "gunk" has to be related to something in the intake AIR process, either dirt getting past the filter, combined with PCV vapors, or exhaust gas contamination from pre-PAIR removal. Maybe a combination of both!

 

[Bustanut joker]

Dem be some sweet butterfly's.. Why.. I don't think I'd mind getting 'em dirty.

 

[fudgejerkin1188]

Is this an American fuel issue ? All 3 of the FJRs I've got have done over 50,000 miles and one is approaching 100,000, their throttle bodies look pristine in comparison to the photos posted in this link. UK fuel is 95 or 98 octain and only has about 5% ethanol in it at the moment, are mucky throttle bodies something we have to look forward to ?

 

[MajBach]

You know...I'm really liking this serious technical discussion without someone saying "jes sayin and enuf said"...but can't we take a commercial break with some girlie photos?...with throttle bodies in the foreground of course.

Also would like to add, that it wouldn't matter what octane gas you ran in your FJR in relation to keeping the TB butterflies clean. The injector inlets are downstream of the butteflies. Gas of ANY octane never touches the butterflies, so octane or supplemental additives like Seafoam aren't gonna impact the butterflies.

The "gunk" has to be related to something in the intake AIR process, either dirt getting past the filter, combined with PCV vapors, or exhaust gas contamination from pre-PAIR removal. Maybe a combination of both!

Indeed! Hard to believe that got overlooked for so long. Perhaps you could post some more pictures to illustrate?

 

[SkooterG]

You know...I'm really liking this serious technical discussion without someone saying "jes sayin and enuf said"...but can't we take a commercial break with some girlie photos?...with throttle bodies in the foreground of course.

Also would like to add, that it wouldn't matter what octane gas you ran in your FJR in relation to keeping the TB butterflies clean. The injector inlets are downstream of the butteflies. Gas of ANY octane never touches the butterflies, so octane or supplemental additives like Seafoam aren't gonna impact the butterflies.

The "gunk" has to be related to something in the intake AIR process, either dirt getting past the filter, combined with PCV vapors, or exhaust gas contamination from pre-PAIR removal. Maybe a combination of both!

Indeed! Hard to believe that got overlooked for so long. Perhaps you could post some more pictures to illustrate?

Well, I stayed away as I was irritated my thread got derailed. :angry: IT'S NOT THE OCTANE!!! Or gas.

Fools can spend their money on premium gas to their heart's content for all I care, but it doesn't have anything to do with octane.

Pictures?

Here's a photo of my intake tract taken at the same time as my gunky throttlebodies. IT'S TOTALLY CLEAN. Why? Well I'll make an educated guess that the fuel is cleaning any build-up that might occur.

Save the octane discussions for their own threads please.

 

[Redfish Hunter]

Skooter now that we all got our well deserved spanking, what is the stuff on the throttlebodies? Like I said earlier it is the same stuff on the GM truck throttlebodies and I never did figure out what it was or where it came from. You have any ideas? Theories?

Great pics of the intake runners BTW.

 

[FJRay]

Gotta agree with Skooter. It's got nothing to do with Gas. Somehow oil vapor from the engine or an overoiled aftermarket filter is getting together with crap that makes it past the filter and ends up on the throttle body plates. What isn't stuck there went through the engine but looking at the number of High mile bikes here it must not hurt much. I have to admit I have never looked at mine.

 

[Bustanut joker]

Quite right Greg.. As mentioned up a few posts, the fuel mixture never passes over the butterfly's.

So to reiterate................. You could run monkey piss through the tank if the bike ran on it. Fuel isn't causing the buildup.

Maybe Ross can get a sample of the residue and clear the whole debate up..

 

[johnny80s]

The PAIR system just injects air into the exhaust to burn any unburned fuel hence the popping people experience when it is installed.

Even if you remove the PAIR system there is still a crankcase vent to the airbox (PCV). That is where the oil vapor is coming from.

Why is this such a mystery Greg?

 

[beemerdons]

The PAIR system just injects air into the exhaust to burn any unburned fuel hence the popping people experience when it is installed.

Even if you remove the PAIR system there is still a crankcase vent to the airbox (PCV). That is where the oil vapor is coming from.

Why is this such a mystery Greg?

Sweet Jesus, if johnny80s is correct and I believe that he is: This means that Cockroaches and Italians are going to inherit the Earth! Looking at Pages 5-2 and 5-3 of my factory Yamaha FJR Shop Manual shows it exactly as the Goombah describes, Oh My God!

 

[Constant Mesh]

The throttle valve in my Honda Accord 4 cylinder accumulates grime similarly to the FJR valves. It will affect throttle control particularly just off idle. It needs to be cleaned periodically. There's a direct cable linkage between the accelerator and the valve. The newer Honda's don't use a cable. They have a servo actuated valve controlled by the computer. Don't know how they respond to gunk build-up.

 

[Redfish Hunter]

The throttle valve in my Honda Accord 4 cylinder accumulates grime similarly to the FJR valves. It will affect throttle control particularly just off idle. It needs to be cleaned periodically. There's a direct cable linkage between the accelerator and the valve. The newer Honda's don't use a cable. They have a servo actuated valve controlled by the computer. Don't know how they respond to gunk build-up.

Dammit we're hijacking Skoot's thread again! As I posted earlier that's the same as the '99 to '06 GM truck V8 gas burners. They changed from cable to electronic throttle control in '03. There is no crankcase vent upstream of the butterfly! Yet the gunk is there and it looks almost the same as this stuff. I am more than certain that those truck engines are not in a high performance tune like the FJR. They do it whether you run the factory paper filter or the K&N oiled gauze. I'd love to know what it is and where it comes from.

 

[03HiYoSilver]

I was just reading some posts on the BMW Forum K1300S Stalling issues pointing to Residues on the Throttlebodies as part of the issue:

https://www.i-bmw.com/showpost.php?p=283982&postcount=418

The issue may be related to oil vapors deposited due to what is known as standoff and it could also be oil vapors rising upstream of the injectors during or after hot shutdown...

An easy durability dyno experiment would be to remain WOT after shutdown and repeat hot shut downs.. compare to normal..

Another possible patch might be to raise rpms prior to shutdown then as soon as the key is off go to wot until the crank stops turning as a means to pump out residual fuel vapors.. Just a thought..

https://www.i-bmw.com/showpost.php?p=285568&postcount=445

Hot chamber gasses are easily thermosiphoned back towards the throttle plates explaining one possible aggravating mechanism of deposit formation.

https://www.i-bmw.com/showpost.php?p=296211&postcount=525 this update and it comes to the dealer via the PUMA network (SuperTechs)

"Even bikes with oodles of crud on plates have enough idle compensation to cover up the issue but they still suggest cleaning up the intake as regular 6K maintenance and adding techron concentrate plus when questionable fuel is all that is available. In addition they also confirm that less crud formation has been witnessed by using the uber $ dealer supplied 5w/40 LL bmw labeled oil at the 600 mile which is a bargain if it truly helps."

https://www.i-bmw.com/showpost.php?p=290232&postcount=487

BMW Motorrad Germany. As I am German and also an engineer that seemed appropriate. (Letter From BMW)

Here their answer translated from German to English:

"Problem: idle rpms is not stable and leads to stalls

Explication: Fuel quality inside of USA is not stable. "Mud" gets on damper flap or throttle flap (however you say it in English). This is especially the case if you drive your bike in low rpms frequently.

Recommendations:

Especially in the USA BMW recommend special addends for the fuel and the cleaning procedure. The motorcycle should also be driven at high rpms. (Yeah, I would like to do that in the USA, highest gear and highest rpms )

 

[Bustanut joker]

Again..............

Much Ado aboot nothing.

The constant over anal ising over a none issue is starting to worry me.

Fuking fuel has absolutely nothing to do with it.. However if you sheep out there wanna buy into big oils ******** far be it for me to dissuade you.

 

[HotRodZilla]

Haha...Told you dorks it wasn't the gas! The only thing premium fuel cleans out is your wallet.

 

[Bustanut joker]

Haha...Told you dorks it wasn't the gas! The only thing premium fuel cleans out is your wallet.

Well now.. If everyone carried a wallet like yours.......

Money would be a non issue.

 

[RadioHowie]

Haha...Told you dorks it wasn't the gas! The only thing premium fuel cleans out is your wallet.

Well now.. If everyone carried a wallet like yours.......

Money would be a non issue.

That ain't his purse, *******.....this is

THIS is his Mangina-Care bag