Vacuum hose routing 1994 tenere

[Stefan]

Hi all, just signed up.

I've been biking a good 15+ years, but never had a tenere, or really any all road bike before.

I bought a (really) cheap 1994 3yf 660 tenere some weeks ago in bits.
Total rolling frame, a few boxes, and a trash bag full of bits - kind of job.

Anyway, i'm trying to put this jigsaw back together, and have arrived at a point where google has failed me.

Where does the hose from the right carb with the big plastic thingy on it go?

(tried to upload an image, but this forum didn't love it.)

[Peen]

Is it a thickish length of hose coming off the top of the CV carb with a plastic bit on the end that looks like it might connect into something?

If its the same as my old 4pt xt600, which I think it might be, then it doesnt go anywhere in particular, the end is open to the air and should route somewhere under the seat or tank out of the way.

[Stefan]

Is it a thickish length of hose coming off the top of the CV carb with a plastic bit on the end that looks like it might connect into something?

If its the same as my old 4pt xt600, which I think it might be, then it doesnt go anywhere in particular, the end is open to the air and should route somewhere under the seat or tank out of the way.

Seems legit. That's what i did.

Anyway. Got it all together, starts up real nice, runs well for something out of a bucket. Untill you get yo about 4.5/5k rpm, and it just starts spluttering and missing. Can't put my finger on if it's running rich or lean. Could be an ignition issue, but i just think it starts and runs too well for that.
Pulling the choke is an old hack to see if it run better or worse, better = lean & worse = rich typically, but can't tell it making any differance at those revs.

Any common issues to check on theese?

[donnybach]

Are the carbs set up correctly between the two? 2nd opens 7mm behind first carb on the old bikes, not sure on your year. It might be as simple as second carb not opening at the right time, or air leak or blockage of second carb? If it’s ok at low throttle, then first carb sounds fine.
Choke isn’t sticking is it? I pissed about for ages until I changed mine for the correct type and had to rejet.

[Stefan]

Are the carbs set up correctly between the two? 2nd opens 7mm behind first carb on the old bikes, not sure on your year. It might be as simple as second carb not opening at the right time, or air leak or blockage of second carb? If it’s ok at low throttle, then first carb sounds fine.
Choke isn’t sticking is it? I pissed about for ages until I changed mine for the correct type and had to rejet.

If i recall correctly the second (slave) side on this is year is all vacuum controlled. Membrane etc is in good condition, but obviously can't see if it's working correctly. Valveclearance issues can sometimes ness around with vaccum controlled carbs from experience, but set those to spec before putting the bike together. Choke isn't stickning, no.

I do have a wierd exhaust on it, from a Honda (Dominator/SLR probably) but it shouldn't mess with the mixture that bad should it?

Suppose i'll have to start by looking for vacuum leaks, though there's no obvious place it should, all the hoses are fresh etc.

[bubliman]

Hello Stefan,
It seems you are having the same issue I used to have. My theory being that it's just too lean at high revs.

I resolved it by pulling the carb out giving it a good clean. And then adjusting the throttle based on the manual. I would recommend finding a screwdriver 6mm wide and using that to set it up. If you don't have the manual here is a screenshot of the adjustment steps. Also the pilot jet screw is supposed to be 2.5 turns out.


Here is a pdf scan of the whole manual (its the 1996 model but they are basically the same)

Hope this helps

[motorang]

Sevond carb butterfly valve is opened purely mechanical (see picture in post above) and the resulting vacuum actuates the membrane to lift the slider. May be worth a try to open a bit earlier.