Well, my Drag Pipes came in today and I plan on installing them over the next week.

I've got a ported/polished engine, bored once over, Wiseco pistons, Pro-Design Coolhead with 18cc domes, 35mm Keihen Air Stryker carbs, Paul Turner Pipes.

Am I gonna need to re-jet the carbs or will the jetting be the same with my Paul Turner pipes?

My Air Strykers are jetted with 158 Mains and 42 Pilots. I ride at sea level.

What changes do I need to make now that I will be running with Drag Pipes?

Thanks for your help!

 

I'd say that you're going to have to go considerably larger on the mains. The pilot will most likely stay close. What needle are you running, I reccommend a Keihin CEL needle in the top clip position. I would start out at LEAST with a 175 main and come down. Are they Power Pro's??? I've seen a few ported Banshee's lately with FMF Fatties that ran a 180 main.

 

Hey,I have my banshee that has 165 psi per and I have fmfs and i run 340 main and 35 pilots..I relize you have a bigger motor..that is set up differently..but,Hope this helps
Madpower

 

can some explain why these people have such small main jets in the banshee. Is it because of the larger bore carbs. I have t-5s with 300 mains. where do people get 165, 185 mains. isnt that a little small. my friend also has an 87 banshee with koffman pipes and his carbs are jetted to 280 mains

 

The reason is because your running the stock Mikuni carbs if im not mistaken, other people are running the Keihin carbs wich go by different increments than the stock Banshee Mikuni carbs.

 

AZruffyryder99:

You are correct. I am running Keihen 35mm Air Strykers vs. the stock Mikuni's (28mm??).

When I had FMF pipes and the stock carbs, I ran 290's at sea level.

Anyone else have experience if I have to go up in jet size since I converted from Paul Turner Pipes to Drag Pipes?

I am not real sure who made the pipes. I got them, via Lonestar Racing, from K and T (Kim Muchmore - the best!) Racing in Utah. They are the type with the built in silencers.

 

Actually Rob4092 I was replying to EXOTIC1's question, forgot to put his name in my reply, sorry. If I was doing that you might want to bolt them on, then run it for a little bit before you jet the carbs, then depending on the throttle response and by checking your plug that should tell you what you need, again this is what ->I<- would do. Oh yea when are you going to Rocky Point again? I forgot when the next races are but that would be cool to hook up at comp hill, or the Reef for a Tecate. I usually go with my cousin and 2 other friends which all have Banshees.
Later

99 Banshee

 

Its hard to say for sure, but I have ran the LRD tucks and then went back to my drags and no change was needed. Your pipes are most probably power pro's. If they look like they are two halves and welded together then they could be CPI, but the power pro's are welded one cone at a time.

 

Backcountry:

I went out and got a set of 175 mains. I will install them this weekend.

Do your really think I will need to increase from 158 mains to 175 mains simply by switching from Paul Turner to Drag Pipes?

I have a CEL Clip in the third position. What should I look for that indicates I should move the clip up as you suggested?

Why do I need to move the clip?

Do I need to move the actual Clip up to the top of the Needle, or move the Clip down towards the bottom of the Needle?

How about the Idle/Fuel Mixture adjustment screw. How many turns out should it be?

Thanks!

 

The last Banshee that we set-up ran 172 mains with 35 PWK's that was without drag pipes. Drag pipes will typically require more main jet due to a more aggressive expansion chamber design. The "tuned" effect of the expansion chamber will most likely have a stronger suction and return pulse which will draw more fuel and air thru, which requires more main jet.

Think of it this way. Main jets will cost you about nine dollars a set. You may have to buy 3 or 4 sets before you get it right. A top-end costs $300 in parts and machine work. See what I'm getting at. Granted you can get close, but the variations in everyone's port job, to compression ratios, to riding style, to fuel, to air temp/density, all add to very wide variations. ALWAYS start rich and work your way down. If you want to go fast it requires staying on top of everything, being consistant and don't cut corners. You've spent alot of time getting you machine set-up and now you need to stay focused and ensure that you get dialed in right. Start big and work your way down.

The needle. Most CEL's that we have ran in Banshee's seemed to like the top clip position the best. This was mainly for hillshooting, long range partial throttle cruising may and most likely will require a richer clip position. The top position is the leanest and the bottom position in the richest. Leave your clip in the middle for now. If it's lean, when you open the throttle to around 1/2 to 3/4 it will bog momentarily and then pick up. If it's rich, if will bog down, sputter a tad, and then slowly start to pick up RPM. The mid range jetting isn't as crucial as the main jet, that is, unless you do alot of partial throttle cruising.

The air screw will only effect the idle and pilot circuit about one size. This is going to have to be a ride and effect again. If you can start it cold without any choke, it may be a tad rich. If you roll into the throttle about 1/4 to 1/3 and it doesn't want to start to pick up RPM, most likely you're rich, go down a size on the pilot jet. Typically I try to set-up with the airscrew about 1 1/2 turns out.