Arm rippin torque

[06twostroker]

Well I just ordered an FMF Fatty. After further thought I would like my exhaust to match and it seems it would do what I need. Im just looking for acceleration and more mid range. Im not always super low rpm but I rarely have time to rev it really high. Im on a really tight budget and my stock pipe just broke a baffle today haha

 

[Blaaster]

Now buy a handfull of jets from #260 to #300 and a few b8es spark plugs and read up on plug chops.

 

[06twostroker]

I bought a bunch a while back up to a 290. I have boyesen dual stage reeds removed air box lid and uni filter (no oil injection no tors). Running a 240 main now with stock pilot and needle on the bottom clip. Would I need another pilot? Do you think a 290 is big enough or should I just buy some more jets?

 

[Blaaster]

Stockpilot will be fine.

A #290 main jet should be OK, but I would start at #300 for the first plug chop.

A #240 main seems a bit small with airbox lid off, unifilter and 32:1, even with a rich needle setting.

 

[blasterBruce]

I'm running a Fresh top end with no tors , no oil injection , DMC alien Exhaust K&N Filter for now Have a Uni here , Stock Carb Settings other than 290 main , 93 Octane and Klotz R 50 @ 32:1 And just now past the 3rd heat cycle , After my tanks of gas I will do plug chop and Chime back in here

 

[Triplecrown421]

I'm running a Fresh top end with no tors , no oil injection , DMC alien Exhaust K&N Filter for now Have a Uni here , Stock Carb Settings other than 290 main , 93 Octane and Klotz R 50 @ 32:1 And just now past the 3rd heat cycle , After my tanks of gas I will do plug chop and Chime back in here

thats awsome dude you got that bike going!!!!!!!




as for the jets the fmf site calls for a 270 main jet. i started there and after plug chops found the 270 was bang on. after building the motor abit more aggresive sapprisingly the 270 is still what it needs.

 

[blasterBruce]

thats awsome dude you got that bike going!!!!!!!




as for the jets the fmf site calls for a 270 main jet. i started there and after plug chops found the 270 was bang on. after building the motor abit more aggresive sapprisingly the 270 is still what it needs.

Thanks man , I have a 260-280-290-300 , no 270 , From the advice i have seen with my temps and elevation i should be @ 270 with my air box lid on . I have yet to try the 280 , Think i might change to that after this tank of fuel and see how it reacts !

 

[Triplecrown421]

Thanks man , I have a 260-280-290-300 , no 270 , From the advice i have seen with my temps and elevation i should be @ 270 with my air box lid on . I have yet to try the 280 , Think i might change to that after this tank of fuel and see how it reacts !

nice, yea i ment to recommend the 270 to 06twostroker i think the dmc will tend to take abit richer from what i hear.

 

[blasterBruce]

Yeah thats what i hear as well , Not sure my first DMC exhaust , The 0000 Fine steel wool makes it sound Nice !

 

[06twostroker]

Stockpilot will be fine.

A #290 main jet should be OK, but I would start at #300 for the first plug chop.

A #240 main seems a bit small with airbox lid off, unifilter and 32:1, even with a rich needle setting.

I richened the needle to try and compensate lol. The next jet size up I have is 260. It seemed too rich so I dropped back to 240. My buddy recently blew my top end (which was going again within a week) and the piston crown didnt look too bad altough plug chop would probably be a better way to tell (and I run a little richer than 32:1, probably 28:1 or maybe 26:1). I have jets from 260-290 (plus the stock 230 and the 240).

 

[Blaaster]

I richened the needle to try and compensate lol. The next jet size up I have is 260. It seemed too rich so I dropped back to 240. My buddy recently blew my top end (which was going again within a week) and the piston crown didnt look too bad altough plug chop would probably be a better way to tell (and I run a little richer than 32:1, probably 28:1 or maybe 26:1). I have jets from 260-290 (plus the stock 230 and the 240).

If your premix is about 25:1 you need one size larger main jet to compensate for the oil taking the place of fuel.

More oil = less fuel = leaner fuel/air mix.

The rich needle will not compensate for a too small a main jet, the needle mainly controls 1/2 to 3/4 throttle.

Chuck the 290 in there move the needle to middle clip, and WOT plug chop.

 

[06twostroker]

Alright, thanks man

 

[joeak47]

Now get that cylinder ported and head re-cut!!!

You won't regret it!

As a matter of fact,You'll wonder why you didn't do it a long time ago.

Of course you'll have to purchase some more jets,because once you get the head re-cut and the cylinder ported,you'll be jumping at least another twelve (12) jet sizes. Probably more at your altitude. I'm at 4,500 feet.

 

[06twostroker]

Im outta money now lol. Twelve jet sizes? Holy sh*t!!! So like a 420? Lol

 

[sicivicdude]

Now get that cylinder ported and head re-cut!!!

You won't regret it!

As a matter of fact,You'll wonder why you didn't do it a long time ago.

Of course you'll have to purchase some more jets,because once you get the head re-cut and the cylinder ported,you'll be jumping at least another twelve (12) jet sizes. Probably more at your altitude. I'm at 4,500 feet.

If you jumped 12 jet sizes from stock porting and head to aftermarket, you were running raggedy lean before and are pouring liquid out of the pipe now....

Mikuni jet sizes for the VM26 jump in "10" increments. (290-300-310 etc etc) Just a single jet size is 10 "numbers" and a relatively large swing in jetting.

Keihin jet sizes for the PWK and PJ's (the most commonly used on 2 strokes) jump by 2-3 "numbers" per size. (150-152-155-158 etc etc)

Neither of those numbering systems would jump 12 jet sizes or numbers in either direction due to porting or head mod.

 

[joeak47]

If you jumped 12 jet sizes from stock porting and head to aftermarket, you were running raggedy lean before and are pouring liquid out of the pipe now....

Mikuni jet sizes for the VM26 jump in "10" increments. (290-300-310 etc etc) Just a single jet size is 10 "numbers" and a relatively large swing in jetting.

Keihin jet sizes for the PWK and PJ's (the most commonly used on 2 strokes) jump by 2-3 "numbers" per size. (150-152-155-158 etc etc)

Neither of those numbering systems would jump 12 jet sizes or numbers in either direction due to porting or head mod.

Sicivicdude...

I'm aware that the mikuni jet sizes jump by ten (10).

Lets see... started with a bone stock blaster...
Stock is 230 in the VM26 Mikuni carb ...

1 > 230
2 > 240
3 > 250
4 > 260
5 > 270
6 > 280
7 > 290
8 > 300
9 > 310
10 > 320
11 > 330
12 > 340
13 > 350

Stock bike ran perfectly! (plug chopped)
Modified bike (ported cylinder and re-cut head) runs perfectly (plug chopped) and on a #350 jet

I see a 12 jet "size" increases there and...no liquid pouring out the tail pipe.

Perhaps its magic?

Just changing to a FMF Fatty and no air box lid will /could send you to a 290 jet.

Don't toomeys include a #310 jet with they're pipe kit?

What you just posted above makes absolutely no sense.

 

[Blaaster]

With no porting and a simple clean up of the intake, and polish of the exhaust port I run a #340 main in winter.

My pipe is a DMC Alien with a foam filter directly on the carby throat, 25:1 bean oil and needle on the richest setting.

It runs like a dog with its gonads in a rat trap.

 

[06twostroker]

Bean oil? What is that?

 

[best]

Bean oil? What is that?

Magic stuff, got a smell all its own. Castor oil.
Mom used to give it to me if I was cranky, claimed I was "bunged up" and needed a purge.
Keeps things slippery where ever you put it.

Caster oil, made from beans of the caster plant, and has nothing to do with beavers if you happen to speak latin.

Caster oil, ethyl/methyl alcohol and nitromethane are the recipe for most model plane and car fuels.
I think SiCivicDude is running something like that in his Blaster too?

Castor oil tends to foul up power valves, so I cannot run it but even after 120years it is still daBOMB in 2 strokes.

 

[06twostroker]

No, I dont speak latin. With my country accent I can barely claim to speak English haha. That stuff sounds cool but I figured 2 stroke oil needed to be petroleum based? Never thought of such a thing in an engine