Jetting opinions on my blaster w\my mods

[SoloVRT61]

Im curious to know if you guys think I need to jet with my mods.. I have never jetted a carb before so im not sure where to start out..

My engine mods are

P&P head bored .20 over
UNI air filter w\airbox lid on
Boyesen Power Reeds

and if its anything the tip thats held on my stock silencer with three screws is removed.. the quad came like that.. Thats basicly it

I plan in getting the Toomy B1 soon ..so if you could give me opinions on both set ups with and with out the exhuast Id appreciate it..

Thanks
-Jon

 

[razrman]

well i think the toomey comes with a 330 jet with it so that should clear it up

 

[SoloVRT61]

wow a 330? i was thinking more of a 260-280 if i had to guess... But regardless what about my current mods..

 

[B14573r]

it actually comes with a 310 jet

 

[Oldfart1stATV]

Ditto

It's a 310 I just installed mine the other day. You will also have to adjust the needle/clip one slot down. They give pretty good instructions with the Toomey and it ain't hard.

A

 

[razrman]

oh whoops, mybad i thot it was 330 but 310 is right i remember it said they came with a jet "kit" and when i got it i seen a "jet" no kit just a jet and the instructions said it was then only one i needed so yea and im thinking ur blaster is an older one so you might need to move the needle clip to the 3rd pos. (the middle one) if that already hasnt been done (probably not)

 

[SoloVRT61]

come on people..my curnt mods..what are we talkin here 235 or 240?

 

[razrman]

go 240 and be safe, rather be rich than be lean, i was basing my info on you getting the toomey

 

[B14573r]

exactly. the 310 jet probably way rich but toomey doesnt want to be liable for u runnign ur engine lean

 

[Oldfart1stATV]

Yup

Lean=Death

'course rich runs for crap. Brother Toomey does suggest it with his B1. I, too, was basing the jetting on having the B1.

A

 

[razrman]

no im sure they researched it and i think that if they say that 310 is perfect, then im not gonna argue with the experts

 

[B14573r]

lol it is impossible for it to be perfect because jetting depends on altituede and every body lives at different altitudes. it also is determined by temperature and every blaster is diffrent. it is impossible to have a "perfect" jetting for ever blaster. just ask ne atv shop. they cant tell you the perfect jetting, but tehy can give u an idea where to start. of course toomey is going ot give u a jet that is most likely rich bc if ur engine runs lean bc of them, they are liable

 

[Oldfart1stATV]

and

It's easier to lean a fat jet than milk a small one. I don't know the formulas for a 2 stroke, I'm sure they are easy to get. A typical V8 works off of "cfm"'s which is cubic feet per minute. B14573r is correct in all he stated.

Carb cfm's = (cubic inch's x rpm's) diveded by 3456 then multiply that by your VE%

This will apply I just don't have exper. with these little suckers to know how. When and if I need to figure it out I'll share.

I think I read that the compression ratio on a stock piston was 6:1.

A

 

[B14573r]

to be specific the ratio is 6.6:1 lol it dont matter

 

[Oldfart1stATV]

I dunno...

Down that low .6 helps!! I'm batting around a 240 kit and am wondering what the deal is. Vito's says it's bolt in. Everything I have read says you need to clearance the head. I dunno, I can mock it up and clay out the clearance, just be nice if somebody has been there done that.

A