In middle of valve adjust, need help!

[bikepharmer]

I am taking advantage of some time off by doing some maintenance on my 2008 990 ADV, and ran across this little problem I can't figure out. There is a little brass barb coming off the front intake (one on the back too), but the one on the front looks like there hasn't been a hose attached to it (dusty, muddy, bits of rubber on the barb. I don't recall removing a hose, so I am at a loss to what should attach here.

Can some help out and tell me what hose goes here?

Photo below

[Head2Wind]

hmmmmmm.... don't have a 990 here right now, however that should be either capped (if emissions stuff removed), or it should have the MAP sensor attached to it.....

If emissions removed, then I suggest placing a bolt/screw rather than capping the hose nipple off, otherwise will experience the same problem in the future.

allen head 6mmx1.0x10mm will work, or if you have extras from other stuff, the bolts that hold the vacu-valve to the bottom of the airbox will work as well.

[DSM8]

IIRC that was part of the emissions (maybe SAS) when I dealt with it on my bike. Yes a hose should run to it.

Might want to look at the vacuum line diagram for the motor (don't know where to find one though)

Correction: Those go to the pressure sensor according to the microfiche

[K6KTM]

Doing the valve check on my 08 990 on mine the front cylinder has a blanking screw, the back cylinder has the brass connector in question, connects to the unit above via a black pipe to a electrical unit. I'll get a photo

[Peanuts]

On European bikes there is only one barb per inlet used on the 990, one for each MAP sensor, right front and left rear.

The left front and right rear are stopped up with a normal 8mm hex headed M6 screw.

Photo shows left front.Do US spec bikes have something the Euro bikes dont?

Unless someone has installed a chain oiler that requires vacuum?

[K6KTM]

Nothing to do with SAS IMO

[Peanuts]

Originally Posted by K6KTM

Doing the valve check on my 08 990 on mine the front cylinder has a blanking screw, the back cylinder has the brass connector in question, connects to the unit above via a black pipe to a electrical unit. I'll get a photo

There are two tapped holes per inlet, look on the other side ;)

[K6KTM]

[DSM8]

Originally Posted by K6KTM

Nothing to do with SAS IMO

Your correct they are to the pressure sensors if there is one from each intake to the electrical device.

[K6KTM]

What you can't see in the photo is the front brass connector, basically a mirror image of the rear cylinder, blanking screw, black pipe to electrical "pressure sensor" cheers DSM8

[K6KTM]

Right front :)

[RoundOz]

One barb each TB go to the pressure sensors, the other two barbs are sometimes joined by a piece of hose as a quick and dirty method of blocking them off when the emissions stuff is removed. I used plugs/screws as previously mentioned - any unecessary hose is a point of failure, though keeping the barbs is a convenient method of syncing multi cylinder engines (rather than trusting the sensors and the software to do it) and I was tempted to run two plugged hoses to a convenient accessible location...but didnt. There is mention is some threads that the pressure sensors are not accurate or consistent, and that they should be swapped and checked againts the TuneEcu (or the KTM shop software) readings to see if an offset needs to be applied. To be fair, if using vacuum gauges you should probably test them against each other to see if they agree. Can't say I have done any of these (possibly) anal things...but have been tempted. One man's anal is another man's standard operating procedure...oh, did I really just say that?

[geometrician]

That cylinder was certainly drawing air thru the opening which would make the all air/fuel mixtures lean on the carb'd 950's- I'm wondering what the ECU/EFI computer was doing with that cylinder (if anything) to compensate for the extra (unfiltered) air. Was the bike popping or backfiring? Ever seem to warmup quickly or get hot? Liquid cooling can hide so much & take away loads of heat that would have killed air-cooled engines...

If you aren't going to use the air port(s) it's better to put a screw/bolt in the opening than plug the hose stuck over the barb fitting- all 'rubber' plugs will eventually crack or enlarge from fuel vapor/engine heat & not give a tight fit. I have a pair of 8-10" hoses which are left in place & plugged on the ends until I synch. I can connect my synch gauges without digging around in tonto the barb fittings.

Good thing you found out now & not in the middle of a deep water crossing!

[bikepharmer]

Originally Posted by geometrician

That cylinder was certainly drawing air thru the opening which would make the all air/fuel mixtures lean on the carb'd 950's- I'm wondering what the ECU/EFI computer was doing with that cylinder (if anything) to compensate for the extra (unfiltered) air. Was the bike popping or backfiring? Ever seem to warmup quickly or get hot? Liquid cooling can hide so much & take away loads of heat that would have killed air-cooled engines...

If you aren't going to use the air port(s) it's better to put a screw/bolt in the opening than plug the hose stuck over the barb fitting- all 'rubber' plugs will eventually crack or enlarge from fuel vapor/engine heat & not give a tight fit. I have a pair of 8-10" hoses which are left in place & plugged on the ends until I synch. I can connect my synch gauges without digging around in tonto the barb fittings.

Good thing you found out now & not in the middle of a deep water crossing!

I discovered during the routine valve check (9000 mi on bike). I am the second owner, and at this point don't believe the valves had ever been checked. The bike was running fine, maybe a touch hot (5 bars) in slow traffic, but 4 bars under steady movement. No weird backfiring or anything, but some very mild surging around 3K rpm. Also, there was some fuel smell I was noticing.

There is a tiny hole in the brass barb. Should I just put a short piece of hose and plug it with a bolt?

Bike is stock, and still has all the emissions stuff on it. I would prefer to keep it stock. The rear barb goes to a hose that runs to a sensor, but also T's off, Maybe that hose was supposed to go to the brass barb?

[crofrog]

Man, I wonder how much wear was done to the top end with all the dust that had to make it in there.

I'd consider pulling the cylinder head, and inspecting it and maybe plan on having the cylinder replated and do piston, rings and valves.