I recently got an 01 blaster. 240 big bore kit, full fmf exhaust, stock reeds and air filter. Got it tuned beat I can but still bogs a bit while accelerating and at low speeds. For into carb to see what was in and needle is on 3rd notch, 230 main jet and 32.5 pilot. Read online some people with same setup are running 350 main and 35 pilot. Just curious as to what others thought of this.
what size jets recomended
- Thread starter hippy
- Start date
Quick question: Are you 100% sure you have a 240 big bore kit? Or were you just told the cylinder was a big-bore? No offense; just trying to figure out if the previous owner thought boring the cylinder over .40 made it a 240. See it all the time.
If you have a legit 240 kit, you'll need a # 37.5 pilot jet and a 360 main to start, with the needle in the 4th clip.
If the engine is has just been bored .40 over stock, you'll be OK with a stock (32.5) pilot jet and a # 270 main jet (with the airbox lid on) or a # 300 main jet (with the airbox lid off). And yes, these numbers are rich, but its a great starting point.
I would also raise your needle up one clip from center for the FMF pipe IF you decide to take off the airbox lid.
If you have a legit 240 kit, you'll need a # 37.5 pilot jet and a 360 main to start, with the needle in the 4th clip.
If the engine is has just been bored .40 over stock, you'll be OK with a stock (32.5) pilot jet and a # 270 main jet (with the airbox lid on) or a # 300 main jet (with the airbox lid off). And yes, these numbers are rich, but its a great starting point.
I would also raise your needle up one clip from center for the FMF pipe IF you decide to take off the airbox lid.
230 is WAY lean. You need around a 270 just for the pipe? Is the air box lid off? Is it ported? What elevation do you ride? Put "plug chop in the search box." that will help you. Do a leak down test and check float bowel level before jetting. Carb should be cleaned first too. There is a ton of info on here and that search button will be your best friend.
You might look into getting a bigger carb and a port job. Without it a 240 kit is a waste of money.
You might look into getting a bigger carb and a port job. Without it a 240 kit is a waste of money.
For the sake of testing what works I'm really not 100% its a 240. The guy I traded said he put the 240 big bore kit in, and I could see it happening because he did put the full fmf on and gave an attempt of upgrading the little things, but this guy was also not very bright. And I ride Ruth around 900-1100 ft elevation. Air lid on but could remove.
The float height should be 22mm when measured from the carburetor body to the top of the float with the float and needle just touching.
You'll gain a little more power when you remove the airbox lid. A lot of people do this mod, and it helps. You just have to re-jet.
What color is your cylinder and head? If it is factory black, it has probably just been bored over slightly. If it is bare (as cast) aluminum, you may indeed have a BBK. Got any pics of your Blaster? I can probably tell from a pic what you're dealing with.
You'll gain a little more power when you remove the airbox lid. A lot of people do this mod, and it helps. You just have to re-jet.
What color is your cylinder and head? If it is factory black, it has probably just been bored over slightly. If it is bare (as cast) aluminum, you may indeed have a BBK. Got any pics of your Blaster? I can probably tell from a pic what you're dealing with.
It won't effect performance. I will probably just burn off the motor. I doubt he used high heat paint. I have a stock cylinder with a 240 sleeve in it. I hate to bust your bubble but if he didn't upgrade the carb, air filter, and reeds I doubt he shelled out the cash for a 240 kit. Most people would at least take the air box lid off for a 240. No way to be sure until you measure the cylinder. I was told my blaster was a 240 when I bought it. It was just the .40 over trick. A lot of people actually think this makes the displacement 240 cc. I hope you do have a 240 kit. You need to pull the cylinder and check on that top end though. 230 with that pie = DISASTER!