snow3
New member
I just purchased a set of 2000 mach z 38 carbs. What is base line cold weather jetting for a 835 bender big bore with vforce reeds and bender big bore pipes?
bufalobob
Member
that's a good question. the 38 carbs work best with the case porting. i don't think they will do much without it.
i would start with the case porting specs:
440 mains
40 pilots
air screw 1.5 out
needle #2 from top
that will be rich. probably will end up with 400-420 mains, 37.5 pilots & needle in leanest setting.
if you are running a cold air kit you must run the carb vent tubes into the air box.
bob
i would start with the case porting specs:
440 mains
40 pilots
air screw 1.5 out
needle #2 from top
that will be rich. probably will end up with 400-420 mains, 37.5 pilots & needle in leanest setting.
if you are running a cold air kit you must run the carb vent tubes into the air box.
bob
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snow3
New member
Thanks Buffalo Bob. If I case port and run the big carbs what kind of hp can I expect. Also, what type of head mod can be done to the stock heads even if race gas needs to be used, or should I go with a aftermarket head and if so what size domes should I run? THANKS
bufalobob
Member
snow:
justin fuller ( full power performance ) designed the 835 when he was with bender. high compression - case porting - 38 mm carbs - v-force2 - bender pipes & cut timing key is 191 h.p..
he also built a more exotic version that was 212 hp.
you can reach justin @ 716 699 6299.
bob
justin fuller ( full power performance ) designed the 835 when he was with bender. high compression - case porting - 38 mm carbs - v-force2 - bender pipes & cut timing key is 191 h.p..
he also built a more exotic version that was 212 hp.
you can reach justin @ 716 699 6299.
bob
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snow3
New member
thanks
Bob, does the case porting work well the stock carbs??
bufalobob
Member
magic:
a lot of time was spent by justin & bender perfecting this package. it works best with case porting, v-force2, bender pipes & 38mm ( 2000 ) skidoo machz carbs.
horsepower makes heat & if you are going to trail ride this sled than
you need to install the tunnel cooling kit offered by bender. once installed it is imperatve that you take the time to bleed the system properly to eliminate any & all air. the stock cooling system cannot handle the extra heat created when riding any considerable distance.
my srx with this package ( stock cranking pressure & stock timing ) has over 2000 miles on it without incidence.
bob
a lot of time was spent by justin & bender perfecting this package. it works best with case porting, v-force2, bender pipes & 38mm ( 2000 ) skidoo machz carbs.
horsepower makes heat & if you are going to trail ride this sled than
you need to install the tunnel cooling kit offered by bender. once installed it is imperatve that you take the time to bleed the system properly to eliminate any & all air. the stock cooling system cannot handle the extra heat created when riding any considerable distance.
my srx with this package ( stock cranking pressure & stock timing ) has over 2000 miles on it without incidence.
bob
460-470 mains with non-hooded needles, 410-420 mains with hooded needles. The motor will be lean as hell with 45 pilots, and hooded needle carbs.
bufalobob
Member
glab:
what are hooded & non-hooded needles????????never heard of them?????
bob
what are hooded & non-hooded needles????????never heard of them?????
bob
There is a small hood that surrounds the opening of the needle valve inside the throat of the carb, the bleed type needles are non hooded and just flat, the air is mixed with fuel through the holes before the needle meters it, with the hooded jets, the fuel is mixed with the gas after it is metered with the needle, this is a better set up for a 2 stroke because of the low manifold vacum signal created from the engine.
bufalobob
Member
mr. viper:
glab said hooded & non-hooded needles---i took his statement literally---there is no such thing as a hooded or non hooded needle. as you posted correctly there are different series needle jet tubes that either partially protrude into the carb bore or sit flush to the bore. good explanation.
glab:
your jetting suggestions are not accurate. this morning i dynoed my 835 bender srx @ dynotech. i will post the results in a new thread & you will also be able to go to dynotechresearch.com & view the dyno sheets as soon as jim posts them.
bob
glab said hooded & non-hooded needles---i took his statement literally---there is no such thing as a hooded or non hooded needle. as you posted correctly there are different series needle jet tubes that either partially protrude into the carb bore or sit flush to the bore. good explanation.
glab:
your jetting suggestions are not accurate. this morning i dynoed my 835 bender srx @ dynotech. i will post the results in a new thread & you will also be able to go to dynotechresearch.com & view the dyno sheets as soon as jim posts them.
bob
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bufalobob
Member
yamahaha:
the topic is 38 mm 2000 mach z carbs!!
Snow3:
i edited my jetting specs for you because of my dyno session yesterday.
i had 440 mains with a bsfc of .686. way safe for lake running on cold days.
i also had 37.5 pilots. my 6000-7200 rpm test ranged from .736 bsfc to .963, way too rich for even the coldest days. this was with the needle clip in the middle position.
remember this is with case porting.
bob
the topic is 38 mm 2000 mach z carbs!!
Snow3:
i edited my jetting specs for you because of my dyno session yesterday.
i had 440 mains with a bsfc of .686. way safe for lake running on cold days.
i also had 37.5 pilots. my 6000-7200 rpm test ranged from .736 bsfc to .963, way too rich for even the coldest days. this was with the needle clip in the middle position.
remember this is with case porting.
bob
Apsley Max
New member
What about 94 mach carbs??