Need Smoother Jetting

[IROOST1]

I previously posted that my banshee started great, idled perfect and had snap up to 1/4 throttle. Well i went and put the recommended mains and needle clip position and it took 20 kicks to start it. It revvs fast but i got stuck in the snow in ten feet so i dont know how my top end is doing, it sounded fine. But it died once i got stuck and pulled my clutch in. Its pretty cold out so i dont know if this is normal and i havent had a banshee before. I ussually ride my 04 yz250.

 

When i went into the carbs, i found there were 340 mains and the needle was on the lowest clip and the needle itself was 5N7.

 

Now its 280 mains and middle clip. I was reading on the stock needle i got in the rebuild kit that its a Y151. Should i put stock ones in? Also, when i let off the throttle, it does rev down as fast as it should, what can that be?

 

I will post my mods at the bottom but should i move the clip back down one position to get a less harsh snap? Does my main sound about right? I should have looked what pilot is in there but i was freezing my nads off. Should i get a set of new pilots and what would work for me?

 

 

1999 Yamaha Banshee w/ title

2001 Motor

Bills pipes and silencers(repacked)

Stock Carbs with tor removal kit

Cylinders bored, honed and chamfered by Eric Gorr(.020 over)

Wiseco Prolite Pistons

New welded crank

Pro flow aluminum airbox adapter with K/N filter

Aluminum Boost bottle w/ brand new manifolds

AIRBOX LID ON

 

ILLINOIS, its cold out

[BANSHEEMANIAC]

sounds like your running lean on idle-bottom. thats why its hard to start. try to adjust you air screws. if that dont work, you may need to go bigger on the pilot.

[IROOST1]

But it started great before i changed the main and clip. I dont know what pilot to get, what would be the perfect pilot?

 

Also, i am going to move the clip down one?

[BANSHEEMANIAC]

what is the temp there? what size are your pilots now? and another thing, did you resynch your carbs when you took them off? readjust your airscrews?

Edited December 8, 2006 by BANSHEEMANIAC

[IROOST1]

what is the temp there? what size are your pilots now? and another thing, did you resynch your carbs when you took them off? readjust your airscrews?

 

Its between 0 - 30 here. I dont know what the pilots are. And they are in sync and the the airscrews are at stock setting. I would rather not pull the carbs to see the pilots, i would rather just get new ones and put them in once i get them.

[okbeast]

There's no real way for us to tell you the perfect pilot. I would probably say a 27.5 would be a good start, and screw your air screw all the in then back in out .5 turn, wait 20 seconds for everything to adjust, then ride it, and do this adjustment until you get it where you like it.

 

As for having less "snap"...that's how the 'shees are, that's the powerband kicking in.

[Mullet Man]

i was just speaking with "dejogejr" about this (i'm in IL too)

 

night time temps right now are down to single digits, in the negative with wind chill.

day time temps are getting up to ~mid 20's

 

he recommended a ~350 main, keeping my 27.5 pilot and needle in middle. and play around with the air screws a little bit. (but i use a pro flow adapter and foam filter with no airbox around it now)

 

i was riding mid Nov. when the temp got up to 65 for a couple days, on the 'Toomey perfect jet kit', 280 main, 27.5 pilot. when i got back to the house, coolant was overflowing a little bit, was running lean, too hot. that was when i had the toomey filter and airbox with no lid.

 

if you have been riding in this stuff lately on a 280 main, you might have hurt something internally...!

Edited December 9, 2006 by Mullet Man

[IROOST1]

dejogejr in a previous post told me 280 mains and middle clip. the 340's i took out with the lowest clip position started much easier and stayed running,just no snap mid to top. Now it starts like crap and doesnt stay running. And as soon as i touch the gas, it dies.

 

I was just out there and tried to keep it running and it finally revved up after 20 times starting it, then it just died within 10 feet. WTF. I am going to go back to the settings on it before and just go down from 340 till it gets its snap back.

 

Any suggestions, im gettin pissed since it seems like i lose one thing to get another. And im tired of taking the carbs off.

 

I am also using the 110 race fuel from my decked out yz250 mixed 36:1. Should i go to pump gas?

[dajogejr]

First things first...it's cold, you probably haven't bought fresh gas for your YZ in a while.

 

in your list of mods, race gas is not only a waste, but it may be hurting performance a tad.

 

Try fresh pump gas, mixed at 32:1.

 

With a FULL air box and pipes, I'd say 280 is more than a safe start even for our cold midwest winters... (Yeah, it's getting nippy here too boys!!)

 

Mullet...if I remember correctly, you have NO airbox, just a hacked up stocker with only the very front left over, so...basically a non-existent airbox....am I correct?

 

Generally speaking, a piped shee with full airbox and lid in normal riding temps goes 260 to 280 on the main, stock pilots. Piped shee with airbox, no lid 270 to 300. Stock or 27.5 pilot.

 

Piped shee, no airbox pod filters, 320 to 350. 27.5 pilot or 30...

 

This is at or near sea level, average riding temps 65 to 85 degrees or so....

 

My rule of thumb has been 1 main jet richer for every 25 degree drop in temp or so.

 

SO...our bikes jetted for summer riding normally want 2 to 3 sizes larger mains when it gets chilly. Often, gotta turn the air screw in .5 to 1.0 turns...and, sometimes bump up the pilot if you were already only 1 turn out on the air.

 

Hope this helps...

[IROOST1]

First things first...it's cold, you probably haven't bought fresh gas for your YZ in a while.

 

in your list of mods, race gas is not only a waste, but it may be hurting performance a tad.

 

Try fresh pump gas, mixed at 32:1.

 

With a FULL air box and pipes, I'd say 280 is more than a safe start even for our cold midwest winters... (Yeah, it's getting nippy here too boys!!)

 

Mullet...if I remember correctly, you have NO airbox, just a hacked up stocker with only the very front left over, so...basically a non-existent airbox....am I correct?

 

Generally speaking, a piped shee with full airbox and lid in normal riding temps goes 260 to 280 on the main, stock pilots. Piped shee with airbox, no lid 270 to 300. Stock or 27.5 pilot.

 

Piped shee, no airbox pod filters, 320 to 350. 27.5 pilot or 30...

 

This is at or near sea level, average riding temps 65 to 85 degrees or so....

 

My rule of thumb has been 1 main jet richer for every 25 degree drop in temp or so.

 

SO...our bikes jetted for summer riding normally want 2 to 3 sizes larger mains when it gets chilly. Often, gotta turn the air screw in .5 to 1.0 turns...and, sometimes bump up the pilot if you were already only 1 turn out on the air.

 

Hope this helps...

 

OK, so ill keep the 280 mains, and the middle clip. I will move my airscrew to 1 out. And put in 27.5 pilots. Also, pump gas. And if that doesnt work, i will drop the clip to 4th from the blunt. Thanks, i will have to order the pilots and see once i get them.

[Mullet Man]

Mullet...if I remember correctly, you have NO airbox, just a hacked up stocker with only the very front left over, so...basically a non-existent airbox....am I correct?

 

correct, this is what i will be using with the 350 mains...

http://i16.tinypic.com/48n7dw9.jpg

with 280's, 27.5's, no lid on an airbox, toomey filter, T5's, shee was running a little hot in ~65* weather

 

OK, so ill keep the 280 mains, and the middle clip. I will move my airscrew to 1 out. And put in 27.5 pilots. Also, pump gas. And if that doesnt work, i will drop the clip to 4th from the blunt. Thanks, i will have to order the pilots and see once i get them.

 

 

you gotta remember the new temps and take that into account!

 

with airbox, no lid, in this 20* and colder weather, you will probably want more fuel then 280's. 'dajogejr's' recomendation above was for 65-85 degree temps with full airbox and pipes.

Edited December 10, 2006 by Mullet Man

[IROOST1]

correct, this is what i will be using with the 350 mains...

http://i16.tinypic.com/48n7dw9.jpg

with 280's, 27.5's, no lid on an airbox, toomey filter, T5's, shee was running a little hot in ~65* weather

you gotta remember the new temps and take that into account!

 

with airbox, no lid, in this 20* and colder weather, you will probably want more fuel then 280's. 'dajogejr's' recomendation above was for 65-85 degree temps with full airbox and pipes.

 

I run the airbox lid ON, so 280's SHOULD work.