Long time since I posted about this, so a recap -

XT600E 1995. I replaced exhaust headers with Motads s/s, cleaned up the cylinder head and renewed the carb mounting rubbers, after a lot of trouble with backfiring. Backfiring cured, but it's not running quite right yet. More reluctant to start, hard to get a steady idle, and when it's warmed up, the idle is way too high. If I turn the idle speed down, it won't idle at all when cold. Running at speed is fine, no power loss, all good.

Air leak was my first thought, but a check with a propane torch (unlit) arounf the inlets gave nothing unusual. I've dismantled the airbox and taken the carbs off to have a look. Here's the issue:

Coming from the top of the right-hand carb, just below the flange, is a tube with a thick black breather pipe. This is about 8"/200mm long and ends in a black plastic plug which looks like it ought to be fitted into somewhere. The natural routing of the pipe is back towards the top of the airbox. I realise now that when I put it all back together before, I must have missed this, and it has been dangling in fresh air between the airbox and shock. I'm wondering if this might be the cause of the poor idling. I know it's the wrong carb, but ...

The outlet and pipe aren't shown on the diagram in the manual I have, and I can't find anything on the web either. In fact, I have never seen one on a CV carb before, now I think of it. With the airbox loosened and moved back, I can't see anywhere obvious it would fit. (And it must have been fitted into something, as the end of it is clean and new-looking, whereas the middle bit of the plastic plug has road dirt.) I'm looking for a hole about 10mm wide, but I can't find one.

Any ideas?

Quick suggestions would be great, as she is in bits at the moment and I have to get to work tomorrow!

Thanks all.

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2006 XT660R daily ride, 1994 XT600E about to be reborn, Blog: http://goingfastgettingnowhere.blogspot.com/

I suspect (guess) that you may well find it goes into the bottom of the airbox to scavenge oil kicked up the crank case breather hose.

Thanks, but I doubt that. The pipe doesn't smell oily, and there's plenty in the bottom of the airbox if that were what it was for. The pipe wouldn't reach to the bottom of the airbox in any case, and there are no joints or unions there for it to fit to. It might reach the top or front (engine side) face, but again, no signs of a matching hole

Thanks anyway.

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2006 XT660R daily ride, 1994 XT600E about to be reborn, Blog: http://goingfastgettingnowhere.blogspot.com/

What he said...

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Tom
I'm a country member...

And what I said ...

There's nowhere that I can see for it to go on the airbox. Does anyone have a 94/95 600 who could pop out and have a look? I only want to know where the damn thing goes!

Cheers Tom.

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2006 XT660R daily ride, 1994 XT600E about to be reborn, Blog: http://goingfastgettingnowhere.blogspot.com/

ill nip out to the garage and have a look for you...back in a bit!

just been out and had a look. The pipe in your pic connects to another pipe that comes out from the engine between the rear of the cylinder head and the starter motor, not sure exactly what it is but took a quick photo.


If you need anything else checking then let me know.

Judging from that pic I'd say it connects directly with the crank case breather. (Probably a legacy from Californian pollution laws.)

Elv, that is really helpful, and thank you. The pipe you mention, on mine, comes from the area between the cylinder base and the starter motor and fits onto a stub at the front of the airbox, about 50mm above the crankcase breather where the oil comes from. It seems like it's meant to be there, and attaching it to the carb breather pipe would involve a lot of awkward bends, so I think that's unlikely to be the correct layout, although the diameter of the pipe and the plastic plug is right.

Too dark to work now, so I'll have another look tomorrow. Thanks again, much appreciated.

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2006 XT660R daily ride, 1994 XT600E about to be reborn, Blog: http://goingfastgettingnowhere.blogspot.com/

hmm now youve got me wondering if mine is connected up properly:confused1:

i think i have the same pipe on a 03 model.i dont know were it goes but i have just done 23000 miles with it as it is in the photo:confused1:

I think that is just the vent for the CV diaphragm. :confused1:

Well it is for the TTR600RE.

Mine (2003) doesn't connect to anything, and im pretty sure its right that way.

Mine hangs down between the carb inlet rubbers, behind the cylinder.

Trough that hose you bring atmospheric pressure into secondary carb. Just leave it under seat.