Single FullSpec or Dual Buckshots?

[Project Ski]

Would you prefer a single Full Spectrum 48mm or dual 46mm buckshots?

 

[demolition_x]

why not go with the 49? http://www.blowsion.com/detail.asp?PRODUCT_ID=01-02-150

 

[Project Ski]

i already have both sets. dont want to spend more money.

 

[demolition_x]

how do you like the single 48.

 

[Project Ski]

dont know, havent tried it yet

 

[meatball]

buck shots are racing carbs, not for FS, since they dont use a 'bombsight' fuel meter, their low speed metering is horrible, and transitions from low to mid to high arent great. Since they dont use a bombsight however, they are able to get more fuel in for high speed, since racers usually have holders hold their skis out of the water, and are at high speed all the time, it doesnt matter. Buck shot went for most fuel capacity possible, and so do other non bombsight 'racing' carbs. Freestyle carbs typically always use a bombsight.

 

[SuperJETT]

Single FS. I've had Buckshots before and their bottom end isn't so great. I also had a single 48 Novi and it was super clean and powerful.

Just don't do extended WOT runs.

 

[Project Ski]

I know why you say not to do WOT runs but why would that be? some of these machines come stock with single carbs alot smaller then a 48. You can run all day wide open.

 

[thegoldenboy]

Anyone running a 48mm carb is usually running a motor that demands more air.

A stock 650 can run WOT all it wants on a smaller single carb as its not in demand of as much air.

 

[Big Kahuna]

take into account of porting, higher compression and especially 62T cases, the single does not like WOT runs............ take a 61x case and you have a whole different ballgame.........

 

[Matt_E]

Phill runs a single 44 on a ported, piped 760. It runs WOT all day long.
So - I refuse to believe the carb is the weak link here. A single 44 can flow more than enough fuel and air ofr sustained WOT operation.
I don't think the cases are the problem either. Sorry....both 61X and 62T are more than capable, single or not.

I think the traditional single carb 62T manifold - really a Kawi 650 manifold - is the problem. It has very small runners and harsh angles.

 

[Project Ski]

what if i said they were going on Kawi 750 Small pin cases? Yup i know, im the only Kawi guy here.

 

[Big Kahuna]

Phill runs a single 44 on a ported, piped 760. It runs WOT all day long.
So - I refuse to believe the carb is the weak link here. A single 44 can flow more than enough fuel and air ofr sustained WOT operation.
I don't think the cases are the problem either. Sorry....both 61X and 62T are more than capable, single or not.

I think the traditional single carb 62T manifold - really a Kawi 650 manifold - is the problem. It has very small runners and harsh angles.

Give Todd LeChance a call (TLR), he was one of the first to start the 62T Case / Single Carb conversions.......... ie: Rick Roy.......... He told me specifically when I changed to the single, do not run WOT.........

Maybe it has more to do with port design??? But go back and look at Darin's post about his single Novi 48, he ran it with no jet and could not get it rich enough..............

If it is the manifold then what manifold are you going to run? last time I looked all the conversions used a Kawi 650 manifold???

 

[SuperJETT]

Phill runs a single 44 on a ported, piped 760. It runs WOT all day long.
So - I refuse to believe the carb is the weak link here. A single 44 can flow more than enough fuel and air ofr sustained WOT operation.
I don't think the cases are the problem either. Sorry....both 61X and 62T are more than capable, single or not.

I think the traditional single carb 62T manifold - really a Kawi 650 manifold - is the problem. It has very small runners and harsh angles.

Novi mods the fuel circuit inside to take a longer path to the jets, and it limits the fuel flow IMO. I had the big Mikuni external pump (tried body mounted also), small return restrictor, and even with the main jet completely out of the carb it would not richen up on top.

 

[Matt_E]

Give Todd LeChance a call (TLR), he was one of the first to start the 62T Case / Single Carb conversions.......... ie: Rick Roy.......... He told me specifically when I changed to the single, do not run WOT.........

Maybe it has more to do with port design??? But go back and look at Darin's post about his single Novi 48, he ran it with no jet and could not get it rich enough..............

If it is the manifold then what manifold are you going to run? last time I looked all the conversions used a Kawi 650 manifold???

I am not doubting that the problem is there. What I do call into question is this: that the problem is the single carb, or the cases.

Why can a 61X cylinder be fed just fine with a single 44 (a ported, piped 760 61X at that!!) on 61X cases?
What changes with the 62T cases? The cylinder is still the same. The case in itself doesn't cause the lean condition on top - that just doesn't make sense to me.

That leaves the manifold (and this has been mentioned numerous times by a couple of good builders). That Kawi manifold is for a 650 Kawi engine. The runners are very small, with weird angles. Then you bolt up 62T reed cages - which weren't designed to work with that contraption.

So, if I were running a single on 62T cases, I would buy the ATP Queenford manifold. Several people are running it on 62T cases and big AM cylinders.

Novi mods the fuel circuit inside to take a longer path to the jets, and it limits the fuel flow IMO. I had the big Mikuni external pump (tried body mounted also), small return restrictor, and even with the main jet completely out of the carb it would not richen up on top.

I do remember you mentioning that before. Are you saying that it would run out of fuel even on a 61X cased motor?

 

[Big Kahuna]

Hey Matt, only thing I can think of as far as the cases goes would be effeciency or CFM's (need freestylegeek with one of his theories here!), maybe 61 cases does not flow as much, allowing a richer settings wereas the T cases may flow more CFM (air) and not enough fuel???? who knows.... I do know that mine ran great until you pinned it and held it...... smoked one piston that way..........

I could still throw a single back on and enjoy riding it, just not for crusing up the lake with Tricky!!!!!!!!!!!!!

 

[cambo au]

two of my mates both have ported 61x with 62t cases one has single riva powerbomb 48 the other dual 46 buckshots and going of the two i would have the low end of the buckshots and the high as well it is the only ski i have ridden with bucks on it but it dose hit hard

 

[Matt_E]

Hey Matt, only thing I can think of as far as the cases goes would be effeciency or CFM's (need freestylegeek with one of his theories here!), maybe 61 cases does not flow as much, allowing a richer settings wereas the T cases may flow more CFM (air) and not enough fuel???? who knows...

I don't think so. The 61X cases flow more than enough to run an identical cylinder WFO all day long - and I don't think my 62T motor with identical porting pulls any more RPMs than Phill's 61X. (Both are identical, except cases and ignition)

Joey (NJFL) is running a single 48 on 62T cases with a 9xx cc ADA cylinder. He is running the ATP manifold. Chucky has commented on this a bunch.
If you run the correct manifold, there won't be WOT trouble.

 

[Big Kahuna]

Who knows. But that is the only difference.............. The Cases.

61x(cases) = Designed for Single Carb
62T(cases) = Dual Carbs

That the only thing That is really different........
other than the ATP Manifold, all the other conversions use a Kawi Manifold...... So, lets just say that it one of 2 things, Cases or The Manifold, that is the only common denominator.........

 

[WaveDemon]

how much is the ATP manifold?