Just Installed New Needles..still no response

[vtecjun]

I have been trying to figure out how to get my banshee to run right since last summer. Everthing is fine once it hits the power band, but the throttle response is terrible. I have a milled head, Toomey T5's, Advance Timing plate, new reeds( cant remember what kind) and an open airbox with K&N fiters. I am running a 270 Main Jet, 27.5 Pilot, and new needles from Vito's with the clip in the middle. The one thing that I noticed about the new needles is that they are about .25" longer than the stock ones. I just put those in tonight and the bike seems to run the same. Boggy and doesnt want to idle for very long. Like I was saying, once it gets going its fine but off the line it is really bad. I am at sea level, and usually ride in Florence and Sand Lake Oregon. I dont mind making adjustments it just seems like anything I try doesnt work. Any input or suggestions would be great. Thanks

[FIRST BANSHEE]

I have been trying to figure out how to get my banshee to run right since last summer.  Everthing is fine once it hits the power band, but the throttle response is terrible.  I have a milled head, Toomey T5's, Advance Timing plate, new reeds( cant remember what kind) and an open airbox with K&N fiters.  I am running a 270 Main Jet, 27.5 Pilot, and new needles from Vito's with the clip in the middle.  The one thing that I noticed about the new needles is that they are about .25" longer than the stock ones.  I just put those in tonight and the bike seems to run the same.  Boggy and doesnt want to idle for very long.  Like I was saying, once it gets going its fine but off the line it is really bad.  I am at sea level, and usually ride in Florence and Sand Lake Oregon.  I dont mind making adjustments it just seems like anything I try doesnt work.  Any input or suggestions would be great.  Thanks

472688[/snapback]

the mains are to small for your setup, try 310-350 depending on temp. do you still have the 25 pilot jets? try those, also try adjusting your air screws for better throttle response. have you cleaned your carbs? do that too.

[Wallrat]

Click benbb's faq in my signature. Throttle response is dictated mostly by the pilot circuit. I also agree with FB.

[banshee tuner]

Sounds to me like the slides are reversed.

[vtecjun]

Is it possible for the slide to be switched? I ddint think the bike would run with them switched. I am running 27.5 for the pilot. Does anyone sell a wideband 02 Setup for a 2 stroke? I am used to tuning with a wideband on my cars, I would assume that someone would have a kit. I dont know if it is lean or rich at idle. I can try the 25 pilot again, but that is where I started when I was initially having the problem. I have also adjusted the screws on the sides of the carbs and they are all the way in. Are there other air screws that I am not seeing? Thanks for all the help guys.

[dennybyz]

with similar set up i ran 280 main never touched pilot ran clip 4th from top ran great air screw should be set at 1 and an eighth turns out .....make sure your not sucking air ....run it and check what plugs look like what mixture are you running ....dont be afraid to run 40:1 sounds to lean but bike runs awsome

[2003LimitedBanshee]

I have also adjusted the screws on the sides of the carbs and they are all the way in.  Are there other air screws that I am not seeing?  Thanks for all the help guys.

473073[/snapback]

 

There's the first part of your problem right there. By turning your air screws all the way in, you are not giving the bike any air (effectively) to idle on. This would give you all around crappy performance. I would install the 25 pilot and open (back out, whatever you want to call it) the air screw by about .5 turn out. When you say you are running an open air box with K&N filters do you mean you still have an airbox with a K&N, or clamp ons. If you are running clamp ons, and no airbox, you should bump your main up several sizes, somewhere in the sub-350 range. How many slots do those Vito's needles have? If it has six it is probably similar (same?) as the Dynojet needle, if so I would set it at the 4th clip from the blunt end. This should get you close. If you still have problems you'll need specific actions under specific conditions.

[vtecjun]

I hope I am on the same page as you guys....the screws on the sides of the carbs, the ones that adjust how far down the slides sit right?

 

I am running no airbox with K&N filters clamped on to the carbs.

 

The Vito's needles are just like stock as far as the positions go. I still am not sure what the extra length of these does.

 

The reason that I have the screws all the way in is because the when I had them out the bike didnt want to start. I would always have to hold the throttle open slightly when kicking it over.

 

Thanks again.

[2003LimitedBanshee]

There are screws the sit perpendicular to the carb bore and hold the slide at the appropriate height to set the idle speed, however this does not affect the idle jetting, only idle speed. Also, your bike will only have this if it is older (pre-TORS) or if someone has removed it from your bike. There are small, flush-mount screws on the left hand side, rear of the carbs that run at about a 45 degree angle. This is your pilot jet air screw. If you've bottomed this out it will not allow enough air for the idle circuit. If it is the first set of screws, idle, that you've bottomed out, the idle speed should be pretty high (assuming the idle screw bosses have been machined to the appropriate height).

 

Edit:

 

Just looked at your profile and you have a '99 which I'm pretty sure should have come with TORS, unless you or someone removed it. Do you have big, clunky do-dads on top of your carbs. If so you've got TORS, and you wouldn't have idle screws, so you would have bottomed out the air screws. After rereading your post, I think this is where your problem is. But you could have a plugged pilot jet or a few other things... Need some more info.

Edited February 14, 2006 by 2003LimitedBanshee

[vtecjun]

The TORS had been removed from the bike before I bought it. I was looking the FAQ that Wallrat told me to look at. In the write up it shows what are the air screws and what are the aftermarket idle screws. I have been adjusting just the idle screws and it still idles low(at least I think so). I havent adjusted the other screw the it shows in the pic. Here is the link to what I am looking at....

 

http://www.dfn.com/benkaren/meatpic1.jpg

 

That is exactly what my carbs look like.

[FIRST BANSHEE]

The TORS had been removed from the bike before I bought it.  I was looking the FAQ that Wallrat told me to look at.  In the write up it shows what are the air screws and what are the aftermarket idle screws.  I have been adjusting just the idle screws and it still idles low(at least I think so).  I havent adjusted the other screw the it shows in the pic.  Here is the link to what I am looking at....

 

http://www.dfn.com/benkaren/meatpic1.jpg

 

That is exactly what my carbs look like.

473276[/snapback]

if the iidle screws where not installed properly they will have litte affect on idle speed. have you made sure your slides are in correct as stated eariler,cutouts toward the air filter. with clamp ons your main is way to small, try 320-350. try lowering your clip1, fourth from top. the longer needle is supose to offer more tunability, buy if yours has only 5 positions, thats not the case. usually the longer needles have 6 slots.

looking back at your first post you said you have a timing plate.what is it set at, make sure somone didn't retard it on accident.

also what is your compression? low compression will make a engine impossible to jet properly. good luck

 

 

[vtecjun]

I will check the timing this weekend to make sure that it is set properly. I cant thank everyone enough for all the help. I will keep everyone posted on my progress. By the way I have milled the head to answer FIRST BANSHEE's question, so I think I should have plenty of compression.

 

Here is another question...where do I go from here? What upgrades would you suggest for a next step? I dont have a boost bottle, not sure if they are worth it.

[FIRST BANSHEE]

boost bottle is a waste of money.

have you put in bigger mains yet? you can mess with that needle all you want but if the main is to small your not going to be able to jet the middle properly.

with proper jetting, t-5s, milled head and +4 degrees timing you should have a strong bottom( for a banshee)

[vtecjun]

OK. Ill change the mains this weekend, and pull off the flywheel and check the timing advance. Thanks again.

[midnite]

  Also, your bike will only have this if it is older (pre-TORS) or if someone has removed it from your bike.

473272[/snapback]

Every banshee that yamaha made came from the factory with the tors system.