bigger jets??

[ina]

my blaster runs really rough when its cold and dies when it gets warmed up.I jetted it from a 260 to a 280 becuase ill be riding in -5 to -10 degrees celcius.I thought maybe the jets were clogged but i cleaned both of them out and it doesnt make a difference.bore is stock size,fmf exhaust,K&N air filter and boyesen reeds.Will jetting it bigger make a difference? maybe a #300 or so?.

 

[Awk08]

yes, go bigger for those temps, I'd start at 340 and plug chop down.
I wouldn't hesitate to drop the needle clip one position too for those temps
stop guessing or it's going to fry...................
http://www.blasterforum.com/threads/how-to-plug-chop.53237/

 

[ina]

doesnt dropping the needle clip make it even leaner??? or is it that when you move it up???

 

[Larry's Shee]

Lower the clip is, the richer needle is because you're starting with the needle that much further out of the main jet.

 

[ina]

o ok. makes sense.

 

[Larry's Shee]

Kind of misspoke. The needle is in the emulsion tube/main jet holder.
You can also get washers to raise or lower the needle a half step.
Check Carb Parts Warehouse , Jets are Us , Sudco.
NOT the hardware store .

 

[ina]

ok so i installed a 310 main and problem solved.only problem now is at top speed it cuts out like its out of fuel.This only happens in 6th gear wide open.If I let off the throttle for a bit and then punch it again it works great for a few seconds then dies again. It also did that when i had a 280 main jet in.Would that be due to incorrect float height?

 

[Larry's Shee]

Check float level,, fuel petcock filter, tank cap and vent. If cap rattes it's good.

Pull fuel line off carb and let it empty into a jar or can, watching for slowdown or stopage. I would not ride until you figure it out. You're risking a lean meltdown.