Quick Carb Question - Jet and emulsion tube replacement

Hello all. Had some stuttering at low rpms in 1st-3rd so I decided to take out the carbs and give them a good cleaning. They look fantastic after running them in an ultrasonic cleaner for a couple of hours. All the jets, emulsions tubes, and other small pieces are nice and shiny. This is my first go at ever cleaning out carbs, but I am wondering if any of the jets require a certain number of turns in, or if they are all just hand tight? I see that the pilot and main jets screw all the way in, but the air jets seem to have quite the range they can be set. Never noted any of this taking them out. Also, as far as the emulsion tube replacement, do the tubes need to be oriented in a certain direction so the holes face a certain way? Thanks anyone who spends the time to respond. This is a great forum with a lot of knowledgeable people.

Thanks,
Nic

 

What model bike? Pilots screws are they only adjustment you can make (apart from float height) I think and the usual recommended start point is 2 full turns out. The rest are screwed in 'hand tight' as you say.

 

I think you are talking about the Pilot/Air mixture screw, as it is the only adjustable item. 2-1/2 turns from a soft bottom ,.

 

Thanks for the responses you two. The bike is an 83 xj750 seca. Ok to be clear on your responses. The main jet, and pilot jet are hand tight (120 and 40 jets). Two two "air jets" (I suppose thats what they're called) are the ones in question. One is an 80 and the other is a 225 i believe and are found in the chamber below where diaphragm sits. The mixture screw is the one on the outside set from the factory that the manual forbids you to touch correct? Just trying to get this straightened out so I can slap these suckers back on the bike and enjoy this nice weather!

Thanks to all
Nic

 

all the jets are hand tightened I do suppose there is a torque spec out there someplace is was there a washer under them ? they should bottom out in the carb.

be aware that the haynes manual shows the main and pilot air jets reversed there is a recent post with the correct location

http://www.xjbikes.com/forums/threads/typo.85507/#post-505006

photo from K-moe's post

 

this link shows a good cutaway of carb bodies

Something New, Something Naked

this link is recomended reading for cleaning carbs
IN THE CHURCH OF CLEAN

 

The torque spec for the jets are as follows. Tight enough to stay in, but no so tight that the driver slot breaks.

There should be a copper washer under the main fuel jet only.

 

The one with the picture I borrowed from RickCoMatic. Nice

 

Thank you all for the help! I drew a diagram of the air jets so I had the orientation right. The carbs were cleaned to hell and back. Everything looked great except for the pilot and main jet driver slots, so i scrapped them and replaced all 8 of them. I took of the valve cover to replace an old leaky gasket and checked the valve clearances and they are all within spec. I have everything reassembled and it is get up and go is amazing. Stutter completely gone. Problem now is it revs really high when in neutral when the bikes warms up. I'm presuming it's an intake manifold leak.

 

Yes,my oh have a vacuum leak somewhere. Carb cleaner sprayed methodically will find it.

 

could be a vacuum leak . check for that . when you set the idle do it after bike has been ridden and is fully warmed up

 

Oh it's for sure a leak in what I believe is one of the intake manifolds. I can see the cracks. It didn't leak before taking the carbs off. In hindsight I was pretty rough trying to get them back in there, shifting them side to side. That had to have done it. What I SHOULD have done was wiped a bit of oil or maybe some silicon grease on the carbs before jamming them in. Lesson learned. I sprayed some carb cleaner on each boot as K-moe suggested and singled out which ones appear to be leaking. I ordered some 3" adhesive lined heat shrink I'm going to try pumping some life into them. I'll do it to all 4. I'll see how the adhesive is, but i'll probably lay down a layer of rtv under it before shrinking it up.