HELP Dirty Throttle body- Ktm 990 adv r

Hi all-
My friend has a Ktm adventure 990 R and we are in the process of doing some needed maintenance on it. Valves,sparkplugs, fluids etc. the list goes on . I had a question about something that came up. So we took off the airbox, his rear throttle body is all dirty/ oil residue in there. In my 990 when I did maintenance the bodies were both dry and clean. He also told me that the rear spark plug was very wet. Also occasionally his bike would smoke a little bit and backfire. I was thinking his bodies need to be synched? Anyone else have some input?

could be tight valves not sealing. how many miles since last valve check?

23,000 haha I'm not so sure he has ever done them.

My rear throttle body (on a 2010) has always had an oily residue at least as long as I can remember. Probably saw it at the first valve check. My bike has 36,000 miles and my valves have never required adjusting. I have never really worried about the oil residue. The bike has always performed flawlessly.

My 2010R has oil residue on rear throttle body as well and valves in spec.Does not seem to burn oil between changes,I just cleaned it up and re-installed. If it ain't broke don't fix it

2009R rear throttle body soiled, front clean as a whistle. Figured the fog from the oil breather would dump down the front inlet but doesn't appear to be doing so.

I doubt if it its any thing with tight valves. Just checked mine and all were in spec.

Mine does pop some in town. Runs good on the throttle. Will monitor.

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2010R rear throttle body was dirty too. just looked at valves at 12k. all in spec. i figured it was the case breather. runs great with Wings no pop or backfire. still that dang snatchy throttle tho.

I have the Akro pipes and a remap and mine does not have a snatchy throttle.
Remap was done on the Dyno by ECunleashed.

Hi all just an update. Measurements were taken today of gaps and shims and everything was pretty close to being in spec. . Will keep everyone in the loop if we find out anything.

2010
All original

12,500 miles ~ Rear Throttle body dirty . Occasional Pop or miss in left pipe at idle . I haven't made it to the valve covers yet .
My throttle seems to have mellowed OR I am just use to it

i had terrible idle pop out of one pipe on my 950. Turned out to be the carb sync. When i synced them and over did it a bit the other cylinder started to pop badly. When in synced it correctly both cylinders ran perfect on idle.



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Is that something I can do with the injection ?
Or do I need to have the dealer do it with the PCM ?

You can get an idea about it in this thread:

http://www.advrider.com/forums/showthread.php?t=841503

But IMO first check for vac leaks going on anywere near that throttle body (ports on the intake, rubber boots, TB proper seating), then I'd check the valve clearances (you are into that anyways, aren't you?) And if everything seems to be fine check the TB sync.

If I recall correctly the rear flow sensor*? (is that what it's called?) is also hooked up to that intake (at the vac port), so it can measure intake air flow or whatever - so any leak in this system could also lead to misfiring/backfiring into the TB. So check the connecting hose for any cracks. Don't know how to check though whether the sensor is working correctly - maybe swap it with the front sensor, and see if the problem shifts to the front cylinder?

*Edit: Looked it up in the fische: 61041085100 PRESSURE SENSOR.

I belive the guys who adjust the TB with TuneECU, rely on the values of these sensors, so if you also have a plugin type flow meter / other syncing tool, you can quite rule out if the problem lays somewhere in here. Also to get the job done properly, if you are really willing to dig into the deep, finding out what's going on, adjusting the sync and the TPS, you'd probably need TuneECU (and lots of free time:)). That said, it can be anything different, like the TB not providing enough fuel/shutting off all the fuel on closed throttle because of a failing TPS, or misinformation from one of the sensors (o2, pressure).. I believe it's quite hard to diagnose, so if the simple things don't solve the problem, maybe living with it is easier and cheaper than fixing it trial-by-error.

Yes I am . Throttle body's off today . Porbley won't get back on it till Wed . Thanks ! I will get that done & see how she runs . I'm not easy on her so I would be surprised if the valves spec out good .

Yes you can sync the throttle bodies.

But like Sumi said, first make sure there are no leaks of any kind. This is crucial as the sync is pointless when you have airleaks.

Syncing is like putting the cherry on top, the rest of the cake has to be perfect to make it work.

My 2008 990S has dirty throttle bodies as well. I keep the valves in spec but they still acquire some varnish (50,000+ miles on the odometer). I think it's normal for these bikes. Possibly due to crank case venting some oil into the airbox?? Not sure, but that would be my guess. Regardless, I wouldn't worry about, check the valves and go from there.

It will be interesting the next time I have the filter off, I recently installed the Rottweiler intake and filter and re routed the crankcase vent hose outside the intake with its own little K&N filter. It should mean my throttle bodies will no longer have oil varnish on them. Maybe?

Comes from acceleration .

The OP says the dirty residues are on the rear TB, the front one is clean, so it seems logical that the bretahing pipe from crankcase cannot be the cause of it as it points directly into the front TB...

Same boat here, a friends 990 is in the same condition, valves are in spec.

If it has residue, it must be a mix of things (fuel + carbon/oil...). Through the TB's things go only one way, fuel and air travel into the intake and combustion chamber.

These two do not produce residue, unless ver bad fuel and/or damaged airfilter, gasoline is used also to clean so its ruled out.

Only way to have it gunky is if anything comes up from the engine valves, and there can be exhaust fumes, unburnt gas, oil traces and carbon buildup.

For this to come up, either tight valves, bad firing/missfiring.. random injector malfunction can have it injecting at wrong times, or weak fuelflow that will have air/fuel mix not be burned due to lean condition...

I'm puzzled..

My valves aren't as bad as I figured they would be but I will be buying shims .

TB residue .... I'm Kinda curious if it is from the crank case vent .
ONLY because I for one have had issues with high oil level .
So far every oil I have used has expanded on me to an over full condition when hot . Even with Motul .
I will try to use Motorex this season since I now am able to buy it . New dealer near me . I would like to find an oil I could pick up on the road tho .

With the numbers that mention it here I'm not real concerned I'll just clean them (TB) during major service .
It is strange to me that only my rear TB is dirty