Carbs

[bikerphil]

Jets are dirt cheap, only problem's getting the old ones out. It requires patience. All the carbs (79-81) if I'm not mistaken, would normally have 42.5's. The later XJ's had I believe 45's or 47.5's. Mikesxs has Mikuni type jets cheap. I've had sucess with 80-81 carbs on the 78-9 head.

[tbishop11]

carbs 4 jets, jets 4 carbs

You are so right thats the problem that I'm facing right now, two of my pilot jet are frozen and stripped, however they are 42.5 jets and I need to go to a 45. And from what I've researched the 78 carbs come with 45 pilots. then I would just need to chand my mains from the 137.5 to 145's. I figure If I can get anouther set then I'll be able to make a funtioning set out of 8 carbs. Mine have other issues too that after a few rebuild attempts aren't being resolved

[Ivan]

I'll try to get some pics for you tomorrow.

[tbishop11]

carbs

sounds great!

[tbishop11]

one problem to anouther?

I totally went throught the carbs that I've got and they're doing o.k, however #2 is not firing could be a ignition issue? I don't really know I've got new plugs and carb intakes with new gaskets, clean fungtioning carbs, so I'm puzzled a little but I think that my carbs are O.k maybe too much air she dies when I push the choke in? Oh well, another day another dollar.

[DGXSER]

Ypu might want to post this in the idle talk XS XJ DISCUSSION area, alot more people that know alot more than me will see it there.

What does #2 plug look like? I take it that even WITH the choke #2 is still not firing, and without choke the bike dies? To much air usually means not enough gas. Did you replace your air jets? Did you ever get those two pilot jets out?

[tbishop11]

1 more cylinder, 1 more to go!

Yes with the choke out shes (#2) still not firing, the plugs are bran new, but the jets are the original jets, however I did finaly get them out and cleaned up like new, I want to wait on replacing the jets until I get it running good and rid for a bit to see how the plugs start looking before I make a drastic changes. Before the cleaning the carbs it was only running on #1 and #4, so I guess at least now its a 3 cylinder. I will check that plug to see if its fouled, or dry today, I know it is sparking at least the last time I checked it.
Thanks

[DGXSER]

For curiosity sake, was the carb on no 2 one that had a stuck jet? How did you get it out?

Of course you probably realize the possible contradiction in your statement "I want to wait on replacing the jets until I get it running good and rid for a bit to see how the plugs start looking before I make a drastic changes." It might be that the changes including the jets are necessary to get it running good. And once it is running good, why in the name of peter and paul would you want to make drastic changes?

[tbishop11]

small jets, easy!

For curiosity sake, was the carb on no 2 one that had a stuck jet? How did you get it out?

Of course you probably realize the possible contradiction in your statement "I want to wait on replacing the jets until I get it running good and rid for a bit to see how the plugs start looking before I make a drastic changes." It might be that the changes including the jets are necessary to get it running good. And once it is running good, why in the name of peter and paul would you want to make drastic changes?

Here's my answers, Yes I realize that is a possible contradiction, and the jets are fine, as far as stock goes. (137.5 main 42.5 pilot) If jets were the problem it wouldn't run like it is on the existing cylinders 1,3,4. However there's a huge difference in running good and running great. A bike can run good and still be lean or rich, with acompaning affects. I just prefer mine to be a little more perfect than that. There's tons of vairiables that affect those things like Air filters, Pipes, Altitude. And as a general rule of thumb you don't change jets until the bike has been running a while and everything is straight, then you can check your plugs or even better run the bike on a DYNO, as for how I got the jets out, I'm a Aerospace Propulsion Mechanic removing a tiny jet is a lot easyier that Fixing huge flying Jets. I was hoping to get anouther set of carbs in the start of this thread in case that removal went south, but it didn't and now i don't need the extra carbs. Thanks For everybodys help and ofers!
Tbishop11 out

[DGXSER]

No problem dude...ride on and have fun!! Wasn't trying to say you were not a strong mechanic, just sometimes the simple things are what evade us, especially when we think we are such accomplished mechanics.

We measly Rocket Scientist (aka...Jet Engine Engineer) won't bother you Aerospace Propulsion Mechanics with any more weak suggestions.

[GARTHXS]

45s

You are so right thats the problem that I'm facing right now, two of my pilot jet are frozen and stripped, however they are 42.5 jets and I need to go to a 45. And from what I've researched the 78 carbs come with 45 pilots. then I would just need to chand my mains from the 137.5 to 145's. I figure If I can get anouther set then I'll be able to make a funtioning set out of 8 carbs. Mine have other issues too that after a few rebuild attempts aren't being resolved

With the 78 series carbs the jetting is larger because of linked fuel passages with the main jets, what kind of exhaust are you running , my 78 has a very highflow exhaust and when I had the bs34II it ran just ok with the 45s but 50s would have been better for pilots, with the bs36 my jetting is much smaller

[tbishop11]

Nice

Thanks for the help! Most everybody has been very helpful, I'm sure she'll get straightened up, that is as soon as I become a rocket scientist thats the only thing holding me back right now J/K

[Dapitbull]

I have a set of carbs off of an 80 model

[tbishop11]

Carbs

I will keep it in mind I think that mine are going to work out, I really apriciate the offer though, thats what I love about xs11.com everybody is so willing to help out! Thanks again.