Quinc
Buy a Superjet
- Location
- California
First time ever seeing something like this. (forsale thread on pwc)
Boswell carbs with energy ports:
Boswell carbs with energy ports:
Carburetor energy ports
- Thread starter Quinc
- Start date
OCD Solutions
Original, Clean and Dependable Solutions
- Location
- Rentz, GA
Looks like a snowmobile thing that maybe tried to crossover?
https://www.snowest.com/forum/archive/index.php/t-115963.html
"Boswell modified carbs are a whole new beast. Forget everything you know about a standard carb. You would be best to try and find a sheet that show's how the circuits work in them.
Great carb once you understand them.
The company has gone out of business and the owner is in Jail due to money problems. "
https://www.snowest.com/forum/archive/index.php/t-115963.html
"Boswell modified carbs are a whole new beast. Forget everything you know about a standard carb. You would be best to try and find a sheet that show's how the circuits work in them.
Great carb once you understand them.
The company has gone out of business and the owner is in Jail due to money problems. "
Quinc
Buy a Superjet
- Location
- California
Thank you Boyer!
Couple different forum posts:
"These Boswell carbs were developed to create more vapor rather than mostly just atomized air/fuel. The evidence that they do this is seen when they can take the throttle without any hesitation when the engine is cold. They don't rely mainly on engine heat for vaporization.
An example of this effect is seen if you ever run a chainsaw out of gas. It suddenly picks up highly vaporized fuel/air just before it runs out of gas. Throttle response goes crazy. This is partially caused by very high vacuum (reduced pressure) in the diaphragm area of the carb. The result is vapor due to better emulsification of the air/fuel molecules. The roundslides and flatslide Boswells have the same effect partially because they use a reversing idle circuitry that becomes a air/fuel air bleed/emulsification circuit when the idle circuit reverses direction. The extra piece at the intake end that isn't present on these carbs is called a Cycler and it also increases this effect by helping to intercept reverse pressure pulses that otherwise re-liquify (Liquifaction) the partially atomized air/fuel mixture into droplets that are too large to burn completely.
I've done hundreds of dyno and field tests on these products.
When diaphragm versions of these carbs are used on a PWC, it usually is so violent at launch, that it "porpoises" straight up out of the water repeatedly as it accelerates.
"
"Boswell Energy Systems developed a modification to stock Mikuni carburetors which was said to improve fuel vaporization and increase engine power while reducing consumption. The Super Cycler was introduced in 1995 and was incorporated in Dale Loritz' Eagle River Championship-winning Formula I sled.
The heart of the technology features tiny holes bored through the wall of the venturi into existing active and originally inactive circuits that lead to the needle jet area of the carb body, where differential air pressure exists. "
Couple different forum posts:
"These Boswell carbs were developed to create more vapor rather than mostly just atomized air/fuel. The evidence that they do this is seen when they can take the throttle without any hesitation when the engine is cold. They don't rely mainly on engine heat for vaporization.
An example of this effect is seen if you ever run a chainsaw out of gas. It suddenly picks up highly vaporized fuel/air just before it runs out of gas. Throttle response goes crazy. This is partially caused by very high vacuum (reduced pressure) in the diaphragm area of the carb. The result is vapor due to better emulsification of the air/fuel molecules. The roundslides and flatslide Boswells have the same effect partially because they use a reversing idle circuitry that becomes a air/fuel air bleed/emulsification circuit when the idle circuit reverses direction. The extra piece at the intake end that isn't present on these carbs is called a Cycler and it also increases this effect by helping to intercept reverse pressure pulses that otherwise re-liquify (Liquifaction) the partially atomized air/fuel mixture into droplets that are too large to burn completely.
I've done hundreds of dyno and field tests on these products.
When diaphragm versions of these carbs are used on a PWC, it usually is so violent at launch, that it "porpoises" straight up out of the water repeatedly as it accelerates.
"Boswell Energy Systems developed a modification to stock Mikuni carburetors which was said to improve fuel vaporization and increase engine power while reducing consumption. The Super Cycler was introduced in 1995 and was incorporated in Dale Loritz' Eagle River Championship-winning Formula I sled.
The heart of the technology features tiny holes bored through the wall of the venturi into existing active and originally inactive circuits that lead to the needle jet area of the carb body, where differential air pressure exists. "
Had real good success running these as spigot mounts on SeaDoo XP 800’s back in the old limited and mod classes
Did not tune like a typical Mikuni, but once tuned, ran very strong. Besides these energy ports, there was third fuel port that targeted mid range. Worked very well!
Did not tune like a typical Mikuni, but once tuned, ran very strong. Besides these energy ports, there was third fuel port that targeted mid range. Worked very well!
- Location
- St. Louis mo
I wanna Check out the add. Can you post the link, can’t find it
Quinc
Buy a Superjet
- Location
- California
pwctoday for sale section. No useful info other then the pictures i posted.
some would deeply dimple the intake portion of the carb and first inch or 2 of intake depending on engine.similar idea in that fuel was kept in suspension better.
this came and went just like turbo cranks
the carb mods boswell did allowed for a more precise control of transition fuel flow but top end was no better.most people did not notice any difference .
If it really was the end all of carb mods,oem's would've jumped all over it 30 years ago.
this came and went just like turbo cranks
the carb mods boswell did allowed for a more precise control of transition fuel flow but top end was no better.most people did not notice any difference .
If it really was the end all of carb mods,oem's would've jumped all over it 30 years ago.
Zero Client
BeerrroooOOOT!!!
- Location
- Douglasville, GA
Strange design. I like the idea. A lot of ideas never made sense though. Fuel injection was another weird one for skis.
Wish Lectron would make a ski carb.
Wish Lectron would make a ski carb.
The heart of the technology features tiny holes bored through the wall of the venturi into existing active and originally inactive circuits that lead to the needle jet area of the carb body, where differential air pressure exists. "
Call me crazy, but it doesn't look to me like those holes in that picture go into the venturi, nor into any "active or originally inactive circuits". If they were doing something with the venturi or something that had anything to do with an actual carb circuit, I would have an easier time believing that it does SOMETHING, even if it probably has nothing to do with "improved fuel vaporization". But that picture sure looks like holes in the mounting flange that go nowhere, and the description sure sounds like a bunch of marketing wank. The air/fuel mixture in a two stroke takes a long and torturous path from the carburetor through the reeds crankcase, transfer ports, into the combustion chamber where it's mixed with a bunch of left over exhaust and partially stuffed out the exhaust port then partially stuffed back in by the pipe. Any claims of increasing atomization or vaporization from a carburetor on a two stroke seem dubious at best.
Call me crazy, but it doesn't look to me like those holes in that picture go into the venturi, nor into any "active or originally inactive circuits". If they were doing something with the venturi or something that had anything to do with an actual carb circuit, I would have an easier time believing that it does SOMETHING, even if it probably has nothing to do with "improved fuel vaporization". But that picture sure looks like holes in the mounting flange that go nowhere, and the description sure sounds like a bunch of marketing wank. The air/fuel mixture in a two stroke takes a long and torturous path from the carburetor through the reeds crankcase, transfer ports, into the combustion chamber where it's mixed with a bunch of left over exhaust and partially stuffed out the exhaust port then partially stuffed back in by the pipe. Any claims of increasing atomization or vaporization from a carburetor on a two stroke seem dubious at best.
Zero Client
BeerrroooOOOT!!!
- Location
- Douglasville, GA
Theres got to be something funny happening when the signal reverbs back from the crankcase under positive pressure - when the piston retracts and reeds close up and the airflow - jitters - lets call it. I'd think some stagnant mixture would be diverted around that Boswell flange some... but as JR. mentioned spigot mount - to me spigot mount is not what we use, ever. When have you seen a spigot mount intake & carb in a ski? We're all ridged mounters.
Looking at that dirt carb above makes me wonder how in the world it would ever fit anyways - unless Boswell made their own intakes I don't see this working well with stock or even Mikuni dirt intakes which are generally spigot mount. The depth of energy ports might cause fitment issues. Not to mention that in the dirtbike and ATV world Mikuni carbs are not so popular especially when the PWK came on the scene. Before the PWK, the PJ was a pile compared to the Mikuni VM and the TM successor.
Fun fact - with skis, Mikuni carbs are a highly popular choice maybe 100:1, but in the dirt world most folks prefer Keihin 10:1.
Mikuni SBN for skis
Keihin PWK for dirt
Looking at that dirt carb above makes me wonder how in the world it would ever fit anyways - unless Boswell made their own intakes I don't see this working well with stock or even Mikuni dirt intakes which are generally spigot mount. The depth of energy ports might cause fitment issues. Not to mention that in the dirtbike and ATV world Mikuni carbs are not so popular especially when the PWK came on the scene. Before the PWK, the PJ was a pile compared to the Mikuni VM and the TM successor.
Fun fact - with skis, Mikuni carbs are a highly popular choice maybe 100:1, but in the dirt world most folks prefer Keihin 10:1.
Mikuni SBN for skis
Keihin PWK for dirt
Quinc
Buy a Superjet
- Location
- California
Kawa uses/used Keihins and groupk talks about how much better they are over the Mikuni. Not sure if Keihins or Sudco still makes pwc carbs?
- Location
- Ontario, Canada
I had a Sudco 42 on an old sx650. It was a horrible carb. Tuning was atrocious, it never held a clean setup without needing re-adjusting and guzzle...that thing was a pig on fuel. I changed it out for a Mikuni SBN44 and never went back. The Mik tuned in within minutes, maintained performance without any re-tweaking and made the ski hugely better on fuel by comparison to the Keihin. The thought has crossed my mind that if the Sudco's were the performance part of choice, why they rarely ever turned up on the used market. It would seem that for every 50 SBNs I see...if not many more, maybe "a", as in just one, Sudco will turn up. I dunno, I just have a hard time believing they were really that good when there doesn't seem to be many of them that ever made it on the water or off the shelf from Sudco. Back in the stand-up racing hayday that was when cool aftermarket parts were booming in sales and the companies were like flower pots, they were everywhere ...and the races were even broadcast on popular channels. We used to have access to a channel called Speedvision, most popular racing broadcaster going in the early to mid 90's. I watched the ski race events almost every weekend back then. <---- a little off topic but it was worth it 
Keihins are junk compared to the Mikuni’s! Back when the early K750’s came out. They came with Keihins stock.
First mod everyone did was trash the Keihins! Sold a lot of Mikuni carbs back then!. The early aftermarket carb guru’s ( Brazina, Green, and others) all swore by the Mikuni. There were a few who were Keihin loyalists. They tried, but could not come close to the performance on the race course! In the bike world, its all side draft with throttle slides instead of butterflys. Whole different application. Not remotely comparable to this conversation.
Racing in the early 90’s was the real hey day for pwc racing!. Local races had at least two qualifers for every class.
Most all classes had full gates of 20 riders for the mains! Riders actually had to qualify at two regional races just to be considered for worlds! Those were some wild times to be a pwc racer! Ahhh the memories.......
First mod everyone did was trash the Keihins! Sold a lot of Mikuni carbs back then!. The early aftermarket carb guru’s ( Brazina, Green, and others) all swore by the Mikuni. There were a few who were Keihin loyalists. They tried, but could not come close to the performance on the race course! In the bike world, its all side draft with throttle slides instead of butterflys. Whole different application. Not remotely comparable to this conversation.
Racing in the early 90’s was the real hey day for pwc racing!. Local races had at least two qualifers for every class.
Most all classes had full gates of 20 riders for the mains! Riders actually had to qualify at two regional races just to be considered for worlds! Those were some wild times to be a pwc racer! Ahhh the memories.......
- Location
- Ontario, Canada
Ahhhh the memories The last race I remember seeing was when Riva made a tripple pipe exhaust I believe for the GP1200R...good times thems was...
The last race I remember seeing was when Riva made a tripple pipe exhaust I believe for the GP1200R...good times thems was...Ahhhh the memories
Have you ever worked on a GPR with triple pipes? Good times they are Not!! Lol
- Location
- Ontario, Canada
LOL...no sir, I have only seen them on the tele. I am personally not a fan of Riva products, what I have worked on made by them has been a thorn in the side. I always try to encourage the guys that have their parts around here to move over to something else a whole more user friendly when install and maintenance times turn up.
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
Those were Factory Pipe systems
- Location
- Ontario, Canada
Interesting, I know it was a Riva sponsored team, I think it was McCluggage on that rig.