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carburator dividing like having a small and large carb ?
Posted: Mon Oct 14, 2013 8:32 pm
by cruzingratiot
from the web site
You will notice the power difference from the bottom end right through the top end. More low end torque, mid range and top end power.
just ran across this
opinions do you think it would work ?
http://www.rb-designs.com/bore-plate-carbs.htm
main web site page
http://www.rb-designs.com/

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Re: carburator dividing like having a small and large carb ?
Posted: Wed Oct 16, 2013 4:44 am
by stepthrutuner
A reputable company like Boyesen would not deal in gimmicks if they did not work.
The "wing" stabilizes the air approaching the slide in the bottom half of the throttle bore. Without the divider, at less than 1/2 throttle the air piles up against the entire slide, producing turbulence and therefore a reduced vacuum signal at the main jet orifice (needle jet). This results in poorer atomization and a need for a larger main to compensates for this lack of vacuum. The divider improves throttle response and slightly improves torque at less than 1/2 throttle. The difference is more noticeable with larger engines.
http://twostrokemotocross.com/forum/tec ... power-now/
Re: carburator dividing like having a small and large carb ?
Posted: Fri Oct 18, 2013 1:19 am
by LMH
Here's the thing, that bore implement does not work for squat in the real world. If you want one my neighbor will sell you a keihen pwk 24mm with it grafted to it for 200$ it was a waste of money and a pain to even try to tune. Say what you will about them not wasting their money on research etc etc, I can tell you from first hand experience dealing with on its horrible. And I know how to tune a carb very well.
Re: carburator dividing like having a small and large carb ?
Posted: Fri Oct 18, 2013 3:56 am
by stepthrutuner
Re: carburator dividing like having a small and large carb ?
Posted: Fri Oct 18, 2013 8:05 am
by LMH
If you buy the product and try it you can be the judge until then I wouldn't believe what you read I a review. It's 100% bs. Same as those tornado or what ever kind of junk they sell now that's suppose to create a turbine in your intake. Buyer beware on these ridiculous waste of money. But from 100% first person experience the divider is 100% worthless, not from some phony review made by someone trying to sell a product.
Re: carburator dividing like having a small and large carb ?
Posted: Mon Oct 21, 2013 3:56 am
by stepthrutuner
I consider your opinion a review and will therefore summarily dismiss it.
Re: carburator dividing like having a small and large carb ?
Posted: Mon Oct 21, 2013 8:58 am
by LMH
I love trying new things out, you never know. Not many of them actually work as intended but it's fun trying.
Re: carburator dividing like having a small and large carb ?
Posted: Mon Oct 21, 2013 9:27 am
by noiseguy
For scooters, which are typically either at idle or WOT, this wouldn't make a bit of difference. Any supposed impact would be at part throttle 1/4-1/2. How often do you ride in that range?
I don't think this is Boyesen. I think it's someone that's modified a Boyesen.
Design tries to increase velocity prior to the air entering the slide. The slide typically does all this work. But now you have a flat plate stuck in the airflow, which would create new turbulence. Overall impact would be to lower airflow during WOT.
The only way to have a small and large carb is to have 2 bores (or 4, in the case of Quadrajets.)
Re: carburator dividing like having a small and large carb ?
Posted: Mon Oct 21, 2013 10:43 am
by LMH
The carb was actually used on a Kaw KX65 with an Athena racing 82cc kit. We ended up using a 28mm with a power jet rather than using the modified 24mm. I built 2 of the exact same engines/bikes and ran the 28mm on one and the modified stocker and the ended up going back to the stock carb from the other one.The modified just didnt want to pull almost like it was obstructed. Put the wideband on it and it wasnt able to ever stabilize at any throttle while moving, did ok at an idle and no load. It felt like it was too fat all the time even tho the AFR was always on the lean side, never felt right after 20 jet and needle changes and wasnt going to keep trying to blow up a 600$ cylinder. It was fun.
Ive ran both the bikes VS yz/kx/and cr 80/85s and they destroy them, Its not even a fair race. I currently have a 01 yz85 Im planning on stroking and boring after I blow it up, if I can that is. I should say these bikes arent for me, theyre my 9 year old twin nephews, but I ride them more than they do.
Re: carburator dividing like having a small and large carb ?
Posted: Wed Oct 23, 2013 2:54 pm
by noiseguy
OK, so what I thought. The flat plate does nothing more than add turbulence / reduce airflow.
Not surprised you couldn't tune it. At just above and below 1/2 throttle, air flow would be all screwed up as air fights between the plate and the slide.
Re: carburator dividing like having a small and large carb ?
Posted: Wed Oct 23, 2013 3:16 pm
by ClemSpree
In general, less things in a carb throat are better, hence why flatslides make more power than CV carbs. Seems silly to put something in the middle of a flatslide.
Re: carburator dividing like having a small and large carb ?
Posted: Wed Oct 23, 2013 6:08 pm
by LMH
It was fun tuning. It definitely adds disturbance to air flow.
Re: carburator dividing like having a small and large carb ?
Posted: Sun Oct 27, 2013 8:14 pm
by veedubh20
Divider damage motor. Lol