Jetting fresh Rebuild

[BMackKC]

i have a 1996 banshee with t5 exhaust and dual k&n airfilter system. I recently had it rebuilt and the thing hasnt ran right since. I have 300 main jets in it. It backfires and spits at low rpms. The banshee has no power. I was racing someone on a z400 and it was killing me. It plain and simple will not pull. It did the same with 270 jets. Are these to big. Before it was rebuilt the 300 mains worked fine now they wont work at all and neither will the 270 mains. What size jets should i be using?

[J.J.]

BMackKC, if I remember correctly, you had a problem with the shift shaft and ball stuck together a while back or am I getting my wires crossed?

 

Anyways, with the symptoms you're describing and considering the fact that you just had a rebuild, I strongly recommend you look for any obvious airleaks, boots around the carbs, carb tops, choke tube, reed cage gaskets etc.

 

In addition I recommend you also do a leak down test to see if there are no leaks from the cases and the crank seal. Do a search for leak down test to get more info, if you can't find anything let us know.

 

If the back firing is common to both cylinders then it's obvious that the leak is also common if you catch my drift...

 

BTW, a 300 mains is just fine for your mods.

[BMackKC]

Yes that was me that had all the clutch problems. It is fixed now. I put a whole new shaft ball adjuster and push lever on it. Then i went ahead and had it bored. It now has 66mm wisco pro lite pistons in it. The guy that did it said i had to much clearence in between the cylinders like 23/1000 clearence. It had compression of 89 in both cyliders. I got it back on the street and it runs but not good enough. It bogs until it hits the powerband. I am mixing the gas at 32:1 is that to rich or about right? Thanks for all the help

[Banchetta]

You didn't put something back together right. If it ran right before than the jetting has nothing to do w/ it...Check your slides in the carbs and make sure the cutaway is facing the air box, also check to see if the choke tube is between the two carbs (1/4" x 2" long) you could also disconnect the tors and go from there.

[96dragbanshee]

I didnt put anything back together the mechanic did it all. this is a problem. I put the 300 mains in last night and it ran fine i dont know if the weather affected them. I will find out today though.

[United Pot Smoker]

try 310's what does the choke test tell you?