Cleaning Throttle Bodies

3dogs · Mar 16, 2011

I want to clean the throttle bodies without disconnecting them from the cyl head. Has anyone removed the airbox and left the throttle bodies in place? How long did this take?

Thanks,

FJRay · Mar 16, 2011

Is there anything wrong with the throttle bodies at this point???? I don't think you want to clean them in place because of the posibility of getting what ever you rinse out inside the engine.

HaulinAshe · Mar 16, 2011

Yes, I've cleaned throttle bodies several times without removal from the crankcase. If you're worried about debris (which is not typical), you can remove the spark plug and rotate the crankshaft until that cylinder intake opens. Then use an air nozzle to force air backward through the intake(s). Mostly what I find is problem residue from re-usable air filter treatments and some light carbon buildup around the butterfly seats.

Removing the air box isn't too difficult, but it does take a long time. The ECU is attached to that assembly and must be disconnected. And you will find the air box nearly impossible to swing out of position without also removing the injector rail assembly. It's a lot of screws but not too much for a Saturday job.

Be sure to plug the injector mounting holes on the throttle body when you remove the injector assembly. Screws have a way of attempting suicide dives into those openings. Also make sure you know where all four(4) injector body seals are at. Some may remain in the throttle body, some may come away with the injectors. It totally sucks to go looking for one.

Bustanut joker · Mar 16, 2011

Seems like Carver or his step sister Scooter had an issue some years back..Er maybe it was howie? :dribble:

Either way I'd start with a twelve pack and pull stuff outa the way,then grab another 12 and kick it off..............

Followed by loading it on a trailer the next day and letting the dealer fix my attempt.

But that's just me.. :dribble:

RadioHowie · Mar 16, 2011

Bustanut joker said:
Seems like Carver or his step sister Scooter had an issue some years back..Er maybe it was howie? :dribble:

Either way I'd start with a twelve pack and pull stuff outa the way,then grab another 12 and kick it off..............

Followed by loading it on a trailer the next day and letting the dealer fix my attempt.

But that's just me.. :dribble:

I NEED to clean my throttle bodies, since they look like this:

.....and when I do decide to strip them off the bike, I'm gonna clean them with one of these:

LINK

.....and a video demo of the above link in action HERE

THEN, when you're all done, you soak the throttle bodies in hot water for a few minutes, since the medium is 100% water soluble.

SkooterG · Mar 16, 2011

Jeff, are you talking about GenIIs specifically?

When I changed my starter I had to do all this. Yep, it was somewhat of a pain, but not that bad. And my TBs were DIRTY!!! Have no idea why. Carver's were the same with a lot less miles.

Clicky for piccies.

wfooshee · Mar 16, 2011

Back when I had my starter issues I had that airbox outa there several times. Jeff hit it pretty straight, it's lots easier if you go ahead and remove the fuel rail, too. Sounds like you're doing more work, but by getting **** out of the way you're saving yourself a LOT of trouble.

Seat off. Tank off. Fuel rail off. Side bodywork off (but not the main fairing panels.) Remove the air filter and unplug the ECU. Remove the tool tray (which the ECU is bolted to.) Unplug that sensor that sits on the airbox, and remove the bracket that holds the back of the gas tank, since it also holds the top of the airbox. There are several hoses to the airbox, including one underneath that you won't find until you lift the airbox and wonder where it came from, unless you're looking for it. So look for it.

The absolute hardest part of the job is getting the airbox ports back onto the throttle bodies. As soon as you think it's there, one tube will pop out. And you have to have them ALL in before you can start tightening the clamps. And don't go through all that and THEN remember the hose that goes in underneath. You'll say bad things and the neighbors will complain about your shouting.

Skoot, if you really have no idea, the throttle bodies get nasty because the crankcase breathes into the airbox. Kinda like PCV on a car, but no valve.

Bustanut joker · Mar 16, 2011

An once again the ghey brigade comes to the rescue..

Thanks ladys.

:blum:

SkooterG · Mar 16, 2011

wfooshee said:
Skoot, if you really have no idea, the throttle bodies get nasty because the crankcase breathes into the airbox. Kinda like PCV on a car, but no valve.

Well, that was one of my leading theories too, but based on where the crankcase ventilation hose enters the airbox it seems there should have been that gunk all over part of the interior of the airbox also. And there was none. ???? Static cling on the TBs?

Bustanut joker · Mar 16, 2011

SkooterG said:
wfooshee said:

Skoot, if you really have no idea, the throttle bodies get nasty because the crankcase breathes into the airbox. Kinda like PCV on a car, but no valve.

Click to expand...

Well, that was one of my leading theories too, but based on where the crankcase ventilation hose enters the airbox it seems there should have been that gunk all over part of the interior of the airbox also. And there was none. ???? Static cling on the TBs?

I think it's more to do with the baby matter Beemerdons injects into your exhaust pipes..

You should know by now any unprotected hole will be violated by the Burro Master.

Constant Mesh · Mar 17, 2011

Don't see any need to clean the throttle valves unless the throttle grip becomes hard to turn or wants to stick in the closed position. In the photo shown above the buildup of soot on the edge of the valve should have no effect on air flow. The lower edge of the butterfly is the leading edge for the inrushing air. The edge appears quite smooth with no buildup. Since the valves don't close completely at idle they're not prone to stick in the idling position.

Needless maintenance I wouldn't perform.

LAF · Mar 17, 2011

SeaFoam Fogger is the ticket here. You warm the motor, hold the butterflies open spray the hell out of them, close them and spray, let sit for 10 mins and fire the bike up. It works very well and cleans piston tops and valve seats also. It dissolves carbon like magic for sure.

I know many have balked at Sea Foam but added to gas it keeps pistons and any part of the fuel system carbon free. I have used it for almost 20 years now and when I rebuilt my Road Glide the pistons were in great shape carbon wise and had Sea Foam in it from day one. I use it in my Turbo car to help keep the turbo from getting carboned up.

I catch it on sale at Auto Zone when they do two fers, and it is not that expensive that way.

I am a firm believer in "better living through chemistry". I use Sea Foam, Marvel Mystery Oil, Sta Bil Marine, and Techtron FI cleaner as part of a treatment for all my gasoline engines, including the tractor and lawn mower.

Gas sucks these days so anything I can do to help I am down for.

Jim Morrison · Mar 17, 2011

I was just going to search for Seafoam use when I saw this...

I use Seafoam in my other bike (carb) and wanted to know if I could use it on the FJR

Thanks

Fred W · Mar 17, 2011

I'm not sure how healthy sea-foam fogging the intake like that would be. Any flushed junk that passes through (hopefully) may very well get hung up in your cats (assuming that you still have them).

I mean, isn't the whole concept of one cleaning the intakes to prevent the accumulated grit and junk from getting sucked into the engine?

Seems like you'd just be precipitating the occurrence.

edit - I guess I'm in the camp that is happy when the grit is stuck in the intake because that stuff didn't get in the engine. If I felt compelled to clean it I'd want to disassemble and wipe or rinse it away, not in.

RadioHowie · Mar 17, 2011

wfooshee said:
Skoot, if you really have no idea, the throttle bodies get nasty because the crankcase breathes into the airbox. Kinda like PCV on a car, but no valve.

SkooterG said:
Well, that was one of my leading theories too, but based on where the crankcase ventilation hose enters the airbox it seems there should have been that gunk all over part of the interior of the airbox also. And there was none. ???? Static cling on the TBs?

There was some discussion on this, as the inside of my airbox was clean and dry, too, but my intake tract from the front side of the throttle bodies all the way to the intake ports was grungy, cruddy, nasty.

Some speculation that the crud is not PCV-related, but rather PAIR related, as in unburned crap being injected back into the intake tract when the PAIR system is active.

Fred W · Mar 17, 2011

RadioHowie said:
Some speculation that the crud is not PCV-related, but rather PAIR related, as in unburned crap being injected back into the intake tract when the PAIR system is active.

That was my hope. And one reason for installing the Wynpro PEPs

ionbeam · Mar 17, 2011

The PAIR air injection port is located in the cylinder head exhaust port right at the exhaust valve and should not be the culprit causing dirty intake tracks.

There is a phenomena known as 'back-streaming' which is likely to be related. Air is viscous and elastic, engine designers use this property to improve volumetric efficiency. During the induction phase the intake valves are open, a mass of air is moving quite rapidly from the air box into the cylinder. At some point the ECU fires the fuel injector misting the air flow with mostly atomized gas. On or about the time the intake valves slam closed the fuel injectors are shut off. If there is any velocity left to the intake air mass, it will strike the back of the intake valves and get reflected back along the intake tract. If there is any trace of atomized fuel left, it is dragged along with the rebounding air mass. The fine traces of fuel will coat the intake track when the air mass becomes still. Any traces of dust that made it past the pores of the air filter will stick to the fuel traces. The design of the cam (timing, overlap and ramp speed), intake runner shape and runner length can make back-streaming much worse or almost non-existent.

wheatonFJR · Mar 17, 2011

I feel like I just got smarter.

Fred W · Mar 17, 2011

ionbeam said:
The PAIR air injection port is located in the cylinder head exhaust port right at the exhaust valve and should not be the culprit causing dirty intake tracks.

True, but the other side of the PAIR valve goes to the clean air side of the Air box. If the PAIR reeds were allowing some back-flow it would be possible for some exhaust gas to be pushed back past the solenoid valve into the airbox.

One would think that if this was the situation that the airbox would show some tell-tale dirt, and most folks report their airboxes are completely clean on the engine side of the filter, so you are probably right that it is back flow through the intake itself.

Cleaning Throttle Bodies

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