Input on where to start with Jetting

[turbowrenchhead]

This is my first banshee. I learned how to jet on my blaster. However I would like a little input on what range of jet sizes I should start with. This is my plan for the mods. Home port stage 3 port job with boyseen ports. ( in progress). Noss head with either 20 or 21 cc domes. I'm shooting for the most compression I can run on 93 octane. Either a +4 or +6 timing mod. FMF pipes and muffs. 65mm cast pistons. I've had bad luck with forged and cold seizers, no I'm gun shy on forged. Stock carbs with tors eliminated. CFM airbox with K&N's. 20" tires. By what I have been reading a 225 main jet might be close. However I have no idea what size needle should be run. Or pilot for that fact.

Thanks in advance for the input.

[bluebanshee98]

This is my first banshee. I learned how to jet on my blaster. However I would like a little input on what range of jet sizes I should start with. This is my plan for the mods. Home port stage 3 port job with boyseen ports. ( in progress). Noss head with either 20 or 21 cc domes. I'm shooting for the most compression I can run on 93 octane. Either a +4 or +6 timing mod. FMF pipes and muffs. 65mm cast pistons. I've had bad luck with forged and cold seizers, no I'm gun shy on forged. Stock carbs with tors eliminated. CFM airbox with K&N's. 20" tires. By what I have been reading a 225 main jet might be close. However I have no idea what size needle should be run. Or pilot for that fact.

Thanks in advance for the input.

wow wow wow with the 225 main jet! your gonna blow that sucker up especially if its ported. heres what i would do... send your cylinders to a site sponsor to get ported to make it do what you want or keep it stock. i would runs pods but if your hard on using the air box then take the lid off, throw in a k&n clamp on airfilter with the adapter, throw some 27.5 pilots and 280 mains in the carbs ( if it is NOT ported) ( if its ported you will be in the 300+ range), get an adjustable timing plate and put it at +4. run stock needle in middle position. im taking it that you are below 2000ft above sea level also so your elevation and temp with effect jetting. also note that when you jet for summer you will need to rejet for winter with bigger jets. learn to use the search function and you will see alot of set ups and jet they use

[sheerider11]

Stage 3 home port? Sounds like a KOC template port job.

[MyNameIsMud]

225 is way too lean.

 

I have basic bolt on bike with T5's,k&n in stock air box,chariot reeds,and +3 and im at 300 mains.

 

Porting will require more because of more air so id start high like maybe 340 or greater and work down.Better safe than sorry.

 

As for the home porting you sir got bigger balls than i.I have seen vids on it and they all make it look easy but to me its a big risk so congrats on it if you pull it off and its sucessful.

 

Got any pics of the progress?

[sheerider11]

225 is way too lean.

 

I have basic bolt on bike with T5's,k&n in stock air box,chariot reeds,and +3 and im at 300 mains.

 

Porting will require more because of more air so id start high like maybe 340 or greater and work down.Better safe than sorry.

 

As for the home porting you sir got bigger balls than i.I have seen vids on it and they all make it look easy but to me its a big risk so congrats on it if you pull it off and its sucessful.

 

Got any pics of the progress?

Porting sucks. I just cleaned up a set of stock jugs it took about 3-4 hours.

I went bigger cause when I went to the other side it was different, it was a lot of back and forth. I did the intakes and transfers.

[turbowrenchhead]

225 is way too lean.

 

I have basic bolt on bike with T5's,k&n in stock air box,chariot reeds,and +3 and im at 300 mains.

 

Porting will require more because of more air so id start high like maybe 340 or greater and work down.Better safe than sorry.

 

As for the home porting you sir got bigger balls than i.I have seen vids on it and they all make it look easy but to me its a big risk so congrats on it if you pull it off and its sucessful.

 

Got any pics of the progress?

[turbowrenchhead]

I'm an auto tech of 19 years. I have done several port and polishes on cars. This is my first port on a 2 stroke. After all the reading and pics on the internet I didn't think it would be that hard. I already have all the carbide bits to do it. This pic is the rough cut. I have to go back through and polish it yet with a dremel.

Thanks for the input on the jets. I'm kinda shocked that you still use the stock needle on the middle position. I thought for sure you would have to go a few sizes rich to match it up. I had to go through 4 needles on my blaster before I found the sweet spot.

Thanks again on the input!

[turbowrenchhead]

wow wow wow with the 225 main jet! your gonna blow that sucker up especially if its ported. heres what i would do... send your cylinders to a site sponsor to get ported to make it do what you want or keep it stock. i would runs pods but if your hard on using the air box then take the lid off, throw in a k&n clamp on airfilter with the adapter, throw some 27.5 pilots and 280 mains in the carbs ( if it is NOT ported) ( if its ported you will be in the 300+ range), get an adjustable timing plate and put it at +4. run stock needle in middle position. im taking it that you are below 2000ft above sea level also so your elevation and temp with effect jetting. also note that when you jet for summer you will need to rejet for winter with bigger jets. learn to use the search function and you will see alot of set ups and jet they use

 

 

Sorry but I dont have unlimited funds. If I can do it I will. I'm at 1000 ft in wisconsin.

[Strm Trpr]

Sounds like you have a solid plan.

Get yourself two Moose Racing Carb Rebuild kits. http://www.farmandsandtoys.com/partdetail.asp?partid=188

Make sure the floats themselves actually float and verify they are set to 21mm float height.

I've heard of them actually leaking and filling with fuel.

Get yourself a Carb Sync Tool from FAST and a cheap eBay tachometer to set your idle and part throttle carb sync.

Below is a link to a tread with vids on syncing and the type of Tach I use to tune.

http://bansheehq.com/forums/index.php?showtopic=155803&view=findpost&p=1354537

 

Do not, I repeat, do not skimp on the following:

 

If you're shooting for the most compression and timing you can run on 93 octane, you better pull the crank out and send it to a site sponsor and have them inspect it and true and weld it.

 

If not, I can almost guarantee the crank will separate and blow the bottom-end up due to the increased compression, timing and your porting!

 

^^^ This is the most important part of my advice to you!

 

A complete gasket kit is only $60.

 

Get yourself a Clymers Manual too.

 

And here's a nice little walk-through on the Banshee's Bottom-End Assembly.

http://bansheehq.com/forums/index.php?showtopic=140912

 

And as far as jetting goes, if you do all that you said in your 1st post, I'd start with 30 Pilots, 360 Mains and the needle on the 2nd clip up from the pointed end.

 

That is a substantial amount of fueling and will require you to tune it.

 

Get a Sync Tool from FAST http://www.farmandsandtoys.com/partdetail.asp?partid=59 and that Tachometer. http://www.ebay.com/itm/Tachometer-Hour-meter-2-4-Stroke-Small-Engine-Spark-for-Boat-Outboard-Mercury-/140669939343?pt=Motors_ATV_Parts_Accessories&hash=item20c094ee8f&vxp=mtr

[turbowrenchhead]

Sounds like you have a solid plan.

Get yourself two Moose Racing Carb Rebuild kits. http://www.farmandsandtoys.com/partdetail.asp?partid=188

Make sure the floats themselves actually float and verify they are set to 21mm float height.

I've heard of them actually leaking and filling with fuel.

Get yourself a Carb Sync Tool from FAST and a cheap eBay tachometer to set your idle and part throttle carb sync.

Below is a link to a tread with vids on syncing and the type of Tach I use to tune.

http://bansheehq.com/forums/index.php?showtopic=155803&view=findpost&p=1354537

 

Do not, I repeat, do not skimp on the following:

 

If you're shooting for the most compression and timing you can run on 93 octane, you better pull the crank out and send it to a site sponsor and have them inspect it and true and weld it.

 

If not, I can almost guarantee the crank will separate and blow the bottom-end up due to the increased compression, timing and your porting!

 

^^^ This is the most important part of my advice to you!

 

A complete gasket kit is only $60.

 

Get yourself a Clymers Manual too.

 

And here's a nice little walk-through on the Banshee's Bottom-End Assembly.

http://bansheehq.com/forums/index.php?showtopic=140912

 

And as far as jetting goes, if you do all that you said in your 1st post, I'd start with 30 Pilots, 360 Mains and the needle on the 2nd clip up from the pointed end.

 

That is a substantial amount of fueling and will require you to tune it.

 

Get a Sync Tool from FAST http://www.farmandsandtoys.com/partdetail.asp?partid=59 and that Tachometer. http://www.ebay.com/itm/Tachometer-Hour-meter-2-4-Stroke-Small-Engine-Spark-for-Boat-Outboard-Mercury-/140669939343?pt=Motors_ATV_Parts_Accessories&hash=item20c094ee8f&vxp=mtr

 

 

I was planning on getting the carb sync tool from fast. I have already watched the syncing vids. I already have a tach on my blaster and planned on installing one on the banshee, great for tuning and making sure your not over revving it. My blaster tops out at 7500 rpm.

Ive got the factory manual already. I get oem parts at wholesale so I will be ordering all new oem gaskets. I haven't decided who to send the crank to yet. My local machinist thinks its a waste of time and money so he won't be doing the work on the crank.

I've got the rebuild kits and tors eliminators, waiting on a good stock carb body. Original one the threads were bad.

Edited June 8, 2012 by turbowrenchhead

[Strm Trpr]

I was planning on getting the carb sync tool from fast. I have already watched the syncing vids. I already have a tach on my blaster and planned on installing one on the banshee, great for tuning and making sure your not over revving it. My blaster tops out at 7500 rpm.

Ive got the factory manual already. I get oem parts at wholesale so I will be ordering all new oem gaskets. I haven't decided who to send the crank to yet. My local machinist thinks its a waste of time and money so he won't be doing the work on the crank.

I've got the rebuild kits and tors eliminators, waiting on a good stock carb body. Original one the threads were bad.

Very well, sounds like you have it all figured out.

 

At the power levels you're talking about, (60-65whp) and pushing the limits of 93 octane like you plan to, if you don't weld the crankshaft and you experience any detonation at high rpm, that crankshaft will not last long and it will come apart and usually very catastrophically.

 

Instead of spending about $100 to have the crank trued and welded, new gaskets, seals and shipping back and forth, you'll more than likely need a whole Banshee engine when the crankshaft comes apart between your knees...