new exhaust and jetting

[08curranc]

hey i have a 97 stock blaster and an 01 blaster. the 01 blaster has fatty gold series pipe and power core 2 silencer.i want to swap the exhaust systems on the blasters but im afraid that the stock jets on the 97 wont work with it and im not sure if the 01 with the exhaust has been rejetted. should i just swap the carbs too and check the 01 carb for rejetting? if its not rejetted what jets should i replace and what jets would be good to start with? im only swapping them because i like the 97 better cause its cleaner and nicer in everyway minus the fact that the 01 is slightly faster and i think its cause the exhaust system.
i know questions like these are answered all the time and it annoying to see them constantly but im new to the blaster world and dont want to ruin or blow anything up. i have read multiple threads but everyone seems to have something different to say...Anything from anyone will help, and helpful links will be great thanks!

 

[89blaster89]

do this put the fmf on the 97 but make sure you rejet the 97with atleast a 280 jet and then plug chop

 

[Blaaster]

We need to know all mods, pipe, air filter, air box lid, pre mix ratio or or injection, elevation and air temperature to give a ballpark figure on main jet sizes.

 

[08curranc]

do this put the fmf on the 97 but make sure you rejet the 97with atleast a 280 jet and then plug chop

am i only replacing the main jet?

 

[08curranc]

the air box lid was previously takin off the 97 not sure what kind of air filter, and its premix. im in san diego right now but im prob gonna end up around lake tahoe with it.

 

[08curranc]

the pip is fmf gold series fatty and power core 2 silencer that im tryin to put on it

the fmf web site recommends a 260 so i may just go with that. is it bad if i run it a lil rich?

 

[Blaaster]

FMF calls for a #260 main.

Foam air filter = 1 or 2 sizes bigger.

Airbox lid off = 2 sizes bigger.

Premix at 32:1 = 1 size bigger.

Plug chop to confirm, altitude and temp can make up to 3 sizes difference either way.

 

[08curranc]

FMF calls for a #260 main.

Foam air filter = 1 or 2 sizes bigger.

Airbox lid off = 2 sizes bigger.

Premix at 32:1 = 1 size bigger.

Plug chop to confirm, altitude and temp can make up to 3 sizes difference either way.

if thats the case maybe i will just start with a 280. will it still run with stock jets? i just waant to put the exhaust on and ride up and down the street till i get new jets. will that be enough to cause damage if i ride around for like a 2 or three days with the exhaust and stock jets?

 

[bummer981]

Of course not having it jetted correctly will cause damage. You will be burning your piston up. Will it blow up in two or three days, not really sure. Why take the chance? Ride the stock bike till you get the jetting right.

 

[Blaaster]

Your impatience could cost you a top end.

Wait until you have the proper jets and confirm with a plug chop.

 

[08curranc]

ok so this is what i found out. my 97 has a 280 main in it already and the 01 has a 340 main. would it be better to use the 280 over the 340with the exhaust? the 01 i also found out while taking it apart has a 13t front sprocket not sure bout the backs but i plan on either swapping the front sprockets too or just buying a new one for the 97. would that also make a difference in the jetting? the 01 seemed to be running fine with the exhaust and the 340 main so i might just swap the mains and exhaust and call it a day for now till i can get to the store and buy some spark plugs. or should i use the 280 for time being? how can having a too small of a jet or too big of a jet effect the quad obviously too small can burn the piston up and ruin top end but what about too big?


*on a side note is a spindle the same as the knuckle? cuz my 01 the front right wheel is cocked inward like this /--| and i was told it was a spindle when i was looking at the diagram of the bike it was listed as steering knuckle

 

[fast02blaster]

The sprocket doesn't effect jetting it only effects ur gearing for tourque or for top speed stock blasters run 13 front teeth and 40 rear teeth if the 01 has all them miss and is running fine I'd swap it all over to the 97 so you know it's right as long s the carb from the 97 is clean leak free and float adjusted correctly all play factors too

 

[08curranc]

The sprocket doesn't effect jetting it only effects ur gearing for tourque or for top speed stock blasters run 13 front teeth and 40 rear teeth if the 01 has all them miss and is running fine I'd swap it all over to the 97 so you know it's right as long s the carb from the 97 is clean leak free and float adjusted correctly all play factors too

how do u adjust the float? i didnt see how u can adjust it while i had the carbs open but i but the 340 main in and put the exhaust onto my 97 from the 01. when i started it up after that it bogged around for like 2-4 minutes with no power really then all of a sudden it started driving normal and i was zipping around. didnt really notice much more power just sounds a lil nicer. the 01 is def still faster then my 97 and it should be stock now minus the 280 main. the 97 has a 14t front sprocket would that make it slower? but im looking for fast acceleration and speed increase. what would be the best set up for that? just 13t in front? or would i have to change the back sprocket too? does changing the sprocket include buying a new chain or will the stock chain still be usable with new gears? i just want my 97 to be as fast as my 01 i cant seem to figure out why it is maybe the engine is just in better condition or maybe its because i took the front fenders off and all the brackets and a few other things to make it lighter?

 

[Blaaster]

Too large a main jet will hinder performance, foul spark plugs and deposit carbon in the ports and header.

It will also cause the packing in the silencer to be rendered useless by excess unburnt oil,

If you really want get up and go, then a 12 tooth sprocket on the front and a 43 on the rear, you will loose lots of speed though.

A new chain must be fitted with new sprockets, and you have to replace them both, old and new do not match and will fight with each other to the point of breakage.

Float level should 20 to 21.5mm on a stock carby.

Before you plug chop to confirm jetting the float level and idle must be set correctly or the smoke ring will lie.

Idle adjusting.

Start with air screw 1.5 turns out.

Set idle screw so that it has some sort of idle. With TORS big screw under seat on top of unit. No TORS brass screw midway down carb body.

Warm up motor and then set idle screw for a faster idle, 2000rpm+

Adjust air screw either way to get the fastest idle.

Adjust air screw a little at a time leaving 10 secs to allow the motor to respond.

Re adjust idle screw for desired idle .

 

[08curranc]

Too large a main jet will hinder performance, foul spark plugs and deposit carbon in the ports and header.

It will also cause the packing in the silencer to be rendered useless by excess unburnt oil,

If you really want get up and go, then a 12 tooth sprocket on the front and a 43 on the rear, you will loose lots of speed though.

A new chain must be fitted with new sprockets, and you have to replace them both, old and new do not match and will fight with each other to the point of breakage.

right on thanks man! the 01 seems like the gears are longer. does the 14t sprocket on the 97 make the gears shorter?

 

[fast02blaster]

14 tooth gives you more top end not more low end if you want some more get up ad go u can leave back the 40 tooth and drop the front to 12 tooth you wil beat the 01

 

[08curranc]

Too large a main jet will hinder performance, foul spark plugs and deposit carbon in the ports and header.

It will also cause the packing in the silencer to be rendered useless by excess unburnt oil,

If you really want get up and go, then a 12 tooth sprocket on the front and a 43 on the rear, you will loose lots of speed though.

A new chain must be fitted with new sprockets, and you have to replace them both, old and new do not match and will fight with each other to the point of breakage.

Float level should 20 to 21.5mm on a stock carby.

Before you plug chop to confirm jetting the float level and idle must be set correctly or the smoke ring will lie.

Idle adjusting.

Start with air screw 1.5 turns out.

Set idle screw so that it has some sort of idle. With TORS big screw under seat on top of unit. No TORS brass screw midway down carb body.

Warm up motor and then set idle screw for a faster idle, 2000rpm+

Adjust air screw either way to get the fastest idle.

Adjust air screw a little at a time leaving 10 secs to allow the motor to respond.

Re adjust idle screw for desired idle .

Thanks a lot for the pics and information a lot. Where is the air screw located and what is a small adjustment like a quater turn?And what do I want to float to be set at?

 

[Larry's Shee]

Air screw is left side of carb near air cleaner boot. A small increment is 1/8 or less, allowing engine to respond, 20-30 seconds, other info already posted, re-read.

 

[08curranc]

Air screw is left side of carb near air cleaner boot. A small increment is 1/8 or less, allowing engine to respond, 20-30 seconds, other info already posted, re-read.

right on thanks man! my bad i was under the impression that the stock float sat at 20-21.5 mm and i was supposed to change it so something else. am i just suppose to make sure its sitting correctly at 20-21mm?

 

[Awk08]

am i just suppose to make sure its sitting correctly at 20-21mm?

that is correct