Carburetor questions 200x.....

[110klt]

I received my new carburetor kit from ebay and had some changes to what was in the carb the way I found it. The idol screw was totally differant it was longer differant and from what I could reasearch it was the correct one. So I am betting the one that was in it was a P.O. fix for the day. Then the book says the main jet is a #110 for an 83 and a #108 for an 84 and up. I am guessing a #110 is the larger of the 2 however mine had a #112 in it. So I am guessing someone played tuner race guy and didn't know what they were doing??? Maybe IDK...

Now here is what I ended up with after. The bike now has a nice steady idol and I don't need to crack the throttle to start it. Throttle response seems to be sharper but that's just the seat of my pants dyno. All this sounds great till this next comment.

I have a nice S&S exhaust I just installed and it's pretty open. However is it common to shoot a small flame out the back during a shap deceleration? Is that meaning it's getting good fuel then when I get off it hard the idol circuit is leaning it out and the excess gas is leaving the exhaust? Or does this mean I am too lean and going to hurt something?????

Don't want to kill a perfectly good motor by ignorance.

[yaegerb]

Have you checked that the exhaust flange is tight against the head or the copper gasket is sealing properly? If those are ok then its a rich condition. Is your plug tip black?

[110klt]

didn't pull the plug it was getting dark and my son wanted to practice his pitching. But anyway I think I will get a new plug in it and start fresh to get a reading. I know the plug was black from the first set up anyway. Oh and the pipe was on the bike before the carb change and it didn't pop before and we rode for 3 hours so I am pretty sure it is good and tight.

[torque]

just an off the hip response it most likely lean.

just removing the airbox lid and an aftermarket air filter can increase the engines need for a bigger main jet?

so what other mods were done to this engine when did you put the s&s pipe on?

what position is the needle at?

just need some more info, but it has been my experience that back firing through the pipe on decel is lean

[yaegerb]

Cool, does the pipe sound good? Let me know what the plug reads.

[110klt]

Pipe sounds great....... It was the only mod that I did to the bike. When I got it the stock pipe was still on but gutted and crappy sounding.

The needle is on the #3 slot like the book says for an 83 and it is where it was on taking it apart.

However my bike is stickered as an 84??????

[yaegerb]

Did you leave the 112 in it?

[110klt]

No I installed the 110 like the book said. an 84 and up calls for a 108...... IDK where a 112 falls into play but I still have it.

Oh and I ran it up the slight hill at my house WOT through 3rd grear and it seemed to run great???????

[110klt]

Ummmmmm just took a look at the old exhaust, it may have not been stock after all. Big loud and beat up a little I just found a partial sticker that after I removed the black spray paint read.

ssani...... as in Bassani possibly?????? Maybe for the reason for the 112 jet???????

[yaegerb]

Yep, bassani. I would put the 112 back in and tune from there. See if it stumbles at 3/4 throttle.