Buckshot carbs (Dual 44's)

[Seb62T]

Hi,
I'm new on this forum, I found some very interesting posts on carbs jetting there. But I would like to have some specific advices on my Setup... Which is not traditionnal.
Her is my 1997 Superjet setup :
-62T cases with 64X cranck
-83mm ported 61X cylinder with Wiseco pistons (5-6 hours sice fresh bore)
-Thundercats dome Girdled head with 35.8cc domes => 170/170PSI
-Coffman lightning Dry Exhauste (the purple big one that looks like the FP Type 9)
-R&D intake manifold ported for VFORCE reeds
-VFORCE2 Reeds (new)
-Dual 44's Buckshot with RIVA air filters
-Modified Stock CDI

I was actually runing 2.3/65g => 15PSI, 110L/110H. The jet is running perfectly in high RPMs, but was not very powerfull in the low RPMs.
I think I had some reeds problems (stock one, but petals are dead). So I changed for VFORCE, but I didn't already test it.

With the 65g spring it happens that my carb leaked.
For this reason, I would like to try a higher popoff setup like : 2.0 / 80gr with 120L / 100H.

What do you think about that ?

Ragards,

Seb

PS : I already asked some tips on PWCToday and already got some answers from Waxhead, but, this is very difficult to find a setup for these carbs. I'm still searching for the drem setup :d

 

[SuperJETT]

Hi,
I'm new on this forum, I found some very interesting posts on carbs jetting there. But I would like to have some specific advices on my Setup... Which is not traditionnal.
Her is my 1997 Superjet setup :
-62T cases with 64X cranck
-83mm ported 61X cylinder with Wiseco pistons (5-6 hours sice fresh bore)
-Thundercats dome Girdled head with 35.8cc domes => 170/170PSI
-Coffman lightning Dry Exhauste (the purple big one that looks like the FP Type 9)
-R&D intake manifold ported for VFORCE reeds
-VFORCE2 Reeds (new)
-Dual 44's Buckshot with RIVA air filters
-Modified Stock CDI

I was actually runing 2.3/65g => 15PSI, 110L/110H. The jet is running perfectly in high RPMs, but was not very powerfull in the low RPMs.
I think I had some reeds problems (stock one, but petals are dead). So I changed for VFORCE, but I didn't already test it.

With the 65g spring it happens that my carb leaked.
For this reason, I would like to try a higher popoff setup like : 2.0 / 80gr with 120L / 100H.

What do you think about that ?

Ragards,

Seb

PS : I already asked some tips on PWCToday and already got some answers from Waxhead, but, this is very difficult to find a setup for these carbs. I'm still searching for the drem setup :d

Wow, this might be an interesting one.

What are the symptoms, how is it running? Does it idle well?

 

[Seb62T]

Wow, this might be an interesting one.

What are the symptoms, how is it running? Does it idle well?

Nice IDLE : I'm opened 0.5 Low and 1.25 High with this setting : 2.3/65/110/110.
It seems to be rich in the low RPMs. Then it's reving quite well and break my arms in the high RPM, plugs have a good color, but my pistons are quite clean... only a little mark on the center, that let me think I'm too rich in the low RPM.

 

[Big Kahuna]

I tried some Bucks years ago, could not get the bottom end right to save my life.............

what I have learned, Buckshots, RedTops, and other race carbs are not set up in mind with strong bottom end response, why? Because at the starting line you are sitting there with your pump out of the water right up to before the band pops, your RPM's are already up some.......... after the start you never really get back into the lowend like you do when coming off the line......... just my $.02..........

anybody got a Penny they can loan me???

 

[SuperJETT]

Here are my tests:
let the ski idle in the water, it should idle forever, if not, adjust the low screws/idle stop screw until it does.

After idling for a minute, you should be able to barely blip the throttle and it yank cleanly. If not, readjust low screws. If it wants to die, it's lean, if it kinda pulls but not clean, it's rich.

then you go up the rpm range, riding around 1/4 throttle to check the low jets, and the high jets are hard to check on a strong SJ but you still can.

popoff, i like to ride at low rpms and just keep popping the throttle, wide open, off, wide open, off, and see if it keeps yanking every time or if it loads up or ends up dieing.

 

[Seb62T]

Here are my tests:
let the ski idle in the water, it should idle forever, if not, adjust the low screws/idle stop screw until it does.

After idling for a minute, you should be able to barely blip the throttle and it yank cleanly. If not, readjust low screws. If it wants to die, it's lean, if it kinda pulls but not clean, it's rich.

then you go up the rpm range, riding around 1/4 throttle to check the low jets, and the high jets are hard to check on a strong SJ but you still can.

popoff, i like to ride at low rpms and just keep popping the throttle, wide open, off, wide open, off, and see if it keeps yanking every time or if it loads up or ends up dieing.

Actually, I adjust the Low speed screw out of water, searching for the fastest REV.

I remember something that was strange, If i increas the Idle speed... The jet doesn't work anymore. It runs crappy. Then I lost the idle screw so the engine died on the idle, but i had a very good response in the low RPM without this scew... That's strange.

Concerning buckshot, they are not "race use only" carbs like most of the people can tell oover the net.
Yes buckshots are hard to tune. But if they are tuned well, they got a great bottom end. For sure is not as esay as blackjack or RIVA or NOVI ones, but you can have very goos results whith these carbs.

If I advance my flywheel of 3°, will I need to get richer ? In which proportion ? +2.5 +5 on L and H jets ?

Thanks for your advices

Seb

 

[waxhead]

if you set it out of the water then you are doing it with no load on it and the setting is incorrect

 

[SUPERTUNE]

These are Old school racing carbs and as BK said not enough bottom end signal with them, you can make them hit better w/higher pop-off/bigger pilot/smaller main but you will have a carb that will load up if you are freestyle/freeriding. Sell them on flea-bay and get a set of brand new matching pair of stock mikuni 46mm's or go w/ a ATP single manifold w/ a novi 48mm freestyle carb. Then you will be miles ahead in the 'I can't tune it!' department....

 

[Seb62T]

These are Old school racing carbs and as BK said not enough bottom end signal with them, you can make them hit better w/higher pop-off/bigger pilot/smaller main but you will have a carb that will load up if you are freestyle/freeriding. Sell them on flea-bay and get a set of brand new matching pair of stock mikuni 46mm's or go w/ a ATP single manifold w/ a novi 48mm freestyle carb. Then you will be miles ahead in the 'I can't tune it!' department....

My carbs are the Modified mikunis not the old billet ones :

I don't want to go to a monocarb.
The best thing would be two RIVA Powerbomb carbs, bon I don't have the money to change my carbs.
I have to do with what I have.

 

[Big Kahuna]

My carbs are the Modified mikunis not the old billet ones.
I don't want to go to a monocarb.
The best thing would be two RIVA Powerbomb carbs, bon I don't have the money to change my carbs.
I have to do with what I have.

Those are the ones we are referring too..........

I am running a set of 44's that Supertune worked up for FLSuperjet (Bought them a few years back from Derek)...... Perfect carbs for freestyle and bottom end response.

 

[SuperJETT]

A single Buckshot works nicely, I've done that before. Dual Buckshots, I've ridden a ski with them and it never had clean bottom end.

Single carb setups can run stronger than you think.

 

[Seb62T]

How much could I sell these carbs ?
What about going on twin blackjack or NOVI 44's ? Or mono 48 RIVA or NOVI ?
Going to a mono 48 won't cost me anything, but what about the top end ?
Cause my setup is more a race setup (exhaust and porting) than a freestyle setup. For this reason, I chose the buckshots.

 

[Big Kahuna]

I would go Novi or Full Spectrum..........Blackjacks are good, harder to tune.

 

[crammit442]

I would go Novi or Full Spectrum..........Blackjacks are good, harder to tune.

I've found Blackjacks to be some of the easiest tuning carbs on the market.:biggthumpup: They run higher popoff than most for clean response. You can also get the Art on the phone easily if you have any questions while tuning. Getting Brazina on the phone is reportedly very difficult sometimes. I wouldn't even consider trading my Blackjacks for Full rectums or novi.

Charles

 

[Shonuff]

I would raise the spring tension to try to get your popoff into the low twenties.

 

[Seb62T]

Here are my tests:
let the ski idle in the water, it should idle forever, if not, adjust the low screws/idle stop screw until it does.

After idling for a minute, you should be able to barely blip the throttle and it yank cleanly. If not, readjust low screws. If it wants to die, it's lean, if it kinda pulls but not clean, it's rich.

then you go up the rpm range, riding around 1/4 throttle to check the low jets, and the high jets are hard to check on a strong SJ but you still can.

popoff, i like to ride at low rpms and just keep popping the throttle, wide open, off, wide open, off, and see if it keeps yanking every time or if it loads up or ends up dieing.

I'm back on the setup of the buckshots !!
Most of my engine parts are now new...
So I decided to start with a 21PSI popoff (2.0 Needle and 80g spring).
I tried 120 Low and 110 High... Too fat in all RPMs.
So I recently tried 105Low 115High with the same popoff... Wow !!!!
Impressive response BUT... (there is always a but) I have an hesitation when leaving the idle.

Here is the test :
-Full throttle on idle => it dies => too lean => opening low speed adjuster from 1 to 1.5 => I'm now too rich in the low RPM and it doesn't work as well as when i'm at 1 turn...

This is a random lag. it is not extremly disturbing... But I would prefer a fine setup !!!
It really works well when the engine revs up.

I don't know what to change to compensate only this short range because it working everywhere else...

If someone get an idea...

 

[Duster8]

I have dual buckshots and i had crappy bottom end power, until freestyleriverrat messed with them the way superjett was explaining earlier. After some tinkering my throttle response became much better and snappier. It still doesnt have a really strong punch to the acceleration, but it felt plenty fast enough for me. And of course the top end is still amazing. superjett, if u were referring to mine, you should ride it now. The last time we went it was running a lot better than it ever has before (until the exhaust hose broke again). I was very impressed though.

 

[vomitspot]

i have buckshots on my ski since 97 i cant even think of needing any more bottem end ! i dont use your setup but ill be happy to share my jetting with you .

 

[Seb62T]

i have buckshots on my ski since 97 i cant even think of needing any more bottem end ! i dont use your setup but ill be happy to share my jetting with you .

Could you tell me more about your setup ??

To compensate the hesitation when leaving the idle, i'll decrease the popoff to richen the very low RPMs and I'll put a smaller pilot jet : 100 instead of 105.
I don't know what I'll do for the Main jet.
I'm thinking about 115 or 120 to stay close the good setting.
I'll probably try : 2.3 needle whith 80gr spring (maybe the 65g spring) / 110 Pilot / 115Main. Just to see how it runs with this setup...

 

[Big Kahuna]

I'm back on the setup of the buckshots !!
Most of my engine parts are now new...
So I decided to start with a 21PSI popoff (2.0 Needle and 80g spring).
I tried 120 Low and 110 High... Too fat in all RPMs.
So I recently tried 105Low 115High with the same popoff... Wow !!!!
Impressive response BUT... (there is always a but) I have an hesitation when leaving the idle.

Here is the test :
-Full throttle on idle => it dies => too lean => opening low speed adjuster from 1 to 1.5 => I'm now too rich in the low RPM and it doesn't work as well as when i'm at 1 turn...

This is a random lag. it is not extremly disturbing... But I would prefer a fine setup !!!
It really works well when the engine revs up.

I don't know what to change to compensate only this short range because it working everywhere else...

If someone get an idea...

See Bold above........ This is the problem I had, could not get the off idle response to work worth a flip, like I said, these are race carbs, not designed for right off the bottom response, more Mid to high response........ for racing, great carbs, for freestyle, not as good, some have had good luck getting them dialed, wish I had more to offer.