[stanc]

I recently bought a carb re-build kit from a shop aroud here for my 98 Springer that didn't have any instructions in it. It was an older one that they were going to take to a swap meet but had all of the parts in it I need to re-build my carb. I drilled the vacuum port, replaced the spring with the lighter one, put in a 45 slow and 180 main and put the stock needle with one shim in. The bike runs much better, throttle response is great, but have a little cough back through the carb when cold. Should I be using one of the two needles supplied with the kit? One has a lot more taper and is about a 16th longer. I did change the carb stem or whatever you call it that the main screws into to the one in the kit. My evo has a D&D 2into1 Fatcat and SE a/c, otherwise stock.

 

[Ed Y]

The carb stem I believe you're referring to is the emulsion tube. And yes, I'd use their recommended needle and see what that gets you. Their emulsion tube and needle are supposed to be designed to work together. If you're going to stay with the shimmed stock needle, put the stock emulsion back in.

When you say "cough thru the carb" when cold, what are the other conditions and do you mean when the weather is cold or the engine is cold??

 

[stanc]

It's when the engine is cold. I get some spitting back through the breather. Which needle of the two supplied with the kit should I use, the more tapered (would it be a sportster needle?)or the one that looks more like the stock one. Thanks for the help, Ed.

 

[Ed Y]

It's when the engine is cold. I get some spitting back through the breather. Which needle of the two supplied with the kit should I use, the more tapered (would it be a sportster needle?)or the one that looks more like the stock one. Thanks for the help, Ed.

If you have no problems with spitting back thru the carb after the engine is warmed up (5 miles or so), then I wouldn't worry about it. Sorry, can't help you with the needle. There are umpteen kits out there and each is slightly different. Couldn't the shop you bought it from, dig up an instruction sheet somewhere for it or at least tell you who made the kit. Doubt very much if it's the sportster needle.

You could bite the bullet and use the stock emulsion tube, buy the $8 sportster needle and use it.

 

[stanc]

Guess I could put the project on hold til I save enough for the sportster needle;D Seriously though, is the sporty needle better? It doesn't tell on the nightrider article any reason to use it. If it is better, maybe my brother-in-law will loan me the money

 

[Ed Y]

Lots of opinions on what's better or what's not. Advantage to the sportster needle is low $$$ compared to other options but you've already spent the $$ on the kit you have so I think I'd try to make it work.

A dyno tune is the only surefire way to get it dialed right but more $$ involved there too.

 

[stanc]

Much obliged for the replys. I'm gonna take the stock needle out and try one of the other. Man, I hate that diaphragm!

 

[Fourcats]

The different needles, {fast taper vs slow taper} will effect performance and fuel milage. To get it sorted out have the ENGINE dyno'd, as mentioned, then you will know for sure. The "spitting" is not worth going crazy over, unless it occurs all the time when the ENGINE has warmed up. -2$en#e-

 

[murphdog]

A couple thousandths difference in needle diameter is a lot. If you can visibly see much more taper in one of the needles vs the other, one of them is going to be way off. Borrow a set of vernier calipers or a micrometer and measure several places along the taper. The one that's slightly smaller in diameter than the stock one will probably work best.

 

[stanc]

Thanks guys. This place is great! Glad I found it!