What size jets to start with

[mangosmoothie]

Hey guys. Just picked up a 93 banshee. I bought from a guy that lives at sea level in phoenix. I took it for a short rip up the street just to make sure it ran. I also ride a 130 whp speed triple so I really didn't know/don't know what I should expect power wise hopping on a banshee. But it seemed like it ran well. I didn't notice any bogging. I live around 5,000 feet. I plan on riding in areas anywhere from 4000-7000 feet. 

The PO didn't know much about the bike. He had like 3 2 stroke dirt bikes, fourtrax 250, quadzilla, etc. It was a very impressive garage lol. He said he bought the banshee as it was and never had to mess with it. He said when he bought it, the top end was just re-done. But he wasn't sure about any porting or anything. From what I can tell, I have FMF gold pipes (no other markings, just says gold) and silencers I can't identify. Big pro design foam filter and plate with the airbox lid removed. I can't tell if the reeds are stock or not. I traces of motoseal or some kind of gasket maker so I don't want to pull them off if there isn't a problem. I pulled the stator cover and it does not look like timing was changed or anything. Looks like the stock plate behind the flywheel. 

So anyway, the carbs were leaking gas out the overflow when I shut the bike off. I pulled them off to see what was up. I noticed the main jets were 330. That seems like a big jet for FMF pipes and a filter mod. Should I just start with those and do a plug chop when I get everything back together since I don't know the history of the bike? Seems like most people with these mods aren't even in the 300's for jet sizes. 

Edited September 2, 2020 by mangosmoothie

[Eric_C1]

Yep, if PO said that's what hes been running in it for awhile I'd just plug chop it there and see what it's at, might have port work done to it if it's not bogging with that fat of a jet in it. do a leak down test too.

[mangosmoothie]

On 9/2/2020 at 12:23 PM, Eric_C1 said:

Yep, if PO said that's what hes been running in it for awhile I'd just plug chop it there and see what it's at, might have port work done to it if it's not bogging with that fat of a jet in it. do a leak down test too.

I got further into the carbs. Has a 30 pilot jet, stock needle position 2, and pilot screw 1 and 1/8 out. Seems like a fat set up if it's just a pipe and filter lol. 

[blsnelling]

Those cylinder would almost have to be ported to be running that fat of jetting.