I am going to switch my 62t to a single carb setup here very shortly. I know there are alot of options, but I am concerned about getting too much carb. Is a 48mm carb (powerbomb, tlr, etc) too much for a 701 (stock porting) with a B pipe, msd enhancer, and head? I know a 46 may be more ideal for this setup but I don't want to have to change carbs down the road when I get my cylinder ported.
Question for you single carb guys
- Thread starter marz831
- Start date
WaveDemon
Not Dead - Notable Member
- Location
- Hell, Florida
twin 38's = 76mm
a single 48 won't be to much.
a single 48 won't be to much.
BombThreat
'Diggity
- Location
- Johnstown, NY
with that why would anyone go bigger on the twin 38's? Alot of the top engine builders say motors upto and beond 900cc's work very well on singles...
WaveDemon
Not Dead - Notable Member
- Location
- Hell, Florida
there are lots of ways to make power. I personally run a 48 on a 790cc motor. I'm thinking of going down to a sbn 46 though.
Come on, not even close.
Dual 38's (if you take 38 as true diameter which they aren't) would be 22.7 sq cm and a single 48 would be 18.1
However, airflow doesn't just go on diameter, etc...
WaveDemon
Not Dead - Notable Member
- Location
- Hell, Florida
whatever, the 38's still flow more.
Why?
WaveDemon
Not Dead - Notable Member
- Location
- Hell, Florida
the 48 is a straight cut throat. the 46 is a stocker with a venturi throat. I think the 46 will give better low end with the stock type throat.
I disagree actually. OEM 38's have a very small flow area compared to a 48, and in pump theory you'll flow more with a larger diameter than with 2 smaller diameters having the same area.
http://www.groupk.com/tec-carbs99.htm has flow #'s for some of the big carbs from back in 99 or so, and the 46's were hitting close to 300cfm where a Keihin 42 didn't even hit 200. Consider that a 48 is bigger, so higher than 300 probably, and a 38 is smaller than a 42, so lower than 200 for sure and you could possibly flow the same with a 48 as dual 38's.
WaveDemon
Not Dead - Notable Member
- Location
- Hell, Florida
good info jett.
I found a 38mm makuni flow rate of 129.5 (it's not a sbn)
http://www.mossbargerracing.com/tuning.htm
the single 48 may flow more.
I found a 38mm makuni flow rate of 129.5 (it's not a sbn)
http://www.mossbargerracing.com/tuning.htm
the single 48 may flow more.
Idok
F1pro
- Location
- Nations oldest muthaF+++kin city
I ran a single TLR 48 on X cases with LPW f/s porting and it had very nice bottom end
ran a 44 on T cases with a Riva manifold and stock porting, had great bottom end as well
Very soon will be building a T cased motor, 48powerbomb with BCW manifold..I have run the manifold before with good success
my personal fav is a 61x cased, 84mm bore with a 48mm port matched system
ran a 44 on T cases with a Riva manifold and stock porting, had great bottom end as well
Very soon will be building a T cased motor, 48powerbomb with BCW manifold..I have run the manifold before with good success
my personal fav is a 61x cased, 84mm bore with a 48mm port matched system
WaveDemon
Not Dead - Notable Member
- Location
- Hell, Florida
anything will be better than the riva manifold. it's a kawi 650 manifold with a conversion plate.
dbrutherford
Parts Whore
- Location
- Fairmont, WV
I think air time products was selling a Yamaha single manifold for Mikuni carbs.
Any other Yamaha single manifolds I have ever seen are just Kawasaki 650 intake manifolds. Then they use an adapter plate to mate it.
I have two X2's and used to have a 650 SX. I have seen my share of Kawasaki 650 parts.
DAVID
Any other Yamaha single manifolds I have ever seen are just Kawasaki 650 intake manifolds. Then they use an adapter plate to mate it.
I have two X2's and used to have a 650 SX. I have seen my share of Kawasaki 650 parts.
DAVID
WaveDemon
Not Dead - Notable Member
- Location
- Hell, Florida
marz, are you looking to buy a sbn 46 to go with that? I may have a spare one now that I'm buying dual 46's.
Nah, I picked up a TLR 48. Once you get yours dialed in, let me know because I may switch if the 46 works better.
WaveDemon
Not Dead - Notable Member
- Location
- Hell, Florida
could you post a pic looking down the throat of the tlr? I used to have a pic of it but lost it.