OMR,

Please investigate the Honda 450r 42mm carb butterfly type TPS (throttle position sensor). Its $170 and has inherent advantages of cv's and fsc's both.
Bolts on stock DS650 intake manifold (perhaps needs porting).
Its the highest tech carb company Keinin - for Honda's any way, and perhaps Harleys due to market position.

An expert like yourself could really offer cyclists an option never before seen.
Reliable performance is Safety.


Thanks Greatly!

 

I second that...but, it doesn't seem many have reported much success with this carb..anyone out there to prove me wrong?

 

I know that oval boring a carb can and does work. the problem you might have is the stock BSR. I think you'll have a hard time with the vaccum slide. If you were talking about a butterfly type carb, then I think you'll be in business. I could be completely wrong though. If you do venture into that world, let us know how it goes. I'm sure many would be very interested.

good luck Dingo

 

Here is something to try that I use myself and love. The HSR 45 carb, then call ronwoods and get the light weight return spring. You can't use the accelerator pump with the light spring, but you can tune you bike in without it and you will have a great running machine with a carb that has a stock like pull.

 

"I know that oval boring a carb can and does work. the problem you might have is the stock BSR. I think you'll have a hard time with the vaccum slide. If you were talking about a butterfly type carb, then I think you'll be in business. I could be completely wrong though. If you do venture into that world, let us know how it goes. I'm sure many would be very interested.

good luck Dingo "


Great suggestion BigDaddy! The 42mm Keinin 450r carb might be good for OMR's Harley bikes as well if a 40mm Keinin cv does as well as it does. This seems like a win-win for the bike community as a whole if OMR could map improvements and capacity flow on a page like the cv is done.

 

I switched to the twist on my TM 45 and I think the pull is lighter than my Harley. It felt natural to me I like it better than the thumb.

 

As any engine builder will tell you, an engine is basically a big air pump. "The more air in and out...the more power it makes." That’s simple enough...why not just install huge carbs to let gobs of air into the engine? The reason...we have to get fuel in along with that air. There in lies the BIG problem. Air is light, and fuel is heavy. This means that we can only add air as long as we can bring the correct amount of heavy fuel along with it. This makes the job of good carburetion infinitely more complex. Getting the carburetor to always draw the correct amount of heavy fuel, along with the lightweight air, is the design goal of every carburetor.
The 42 BSR carb is a production carb that by design is maxed out for its application on the DS. The jet needle has the fastest taper of any mikuni needle produced. The fuel delivery is very poor on top end and thus the most noted reason people say the carb is too small is because of lack of power on top end. Did everyone hear what I said - The carb has poor fuel delivery on top end.
Do not think that the carb is too small. It is just in need of a better fuel curve. That is why I am making my own jet kit because no one wants to remap the fuel curve. The vacuum signal can be adjusted to meet the horsepower requirements for the flow of this carb. Like I have said earlier, that this carb can flow up to 250-260 cfm, that translates into 62 - 65 hp.
Slide control is controlled not only by drilling out more ports in the slide, per my already stated mods, but an additional feature is included. I am concentrating on movement of the heavy fuel and atomization improvements.
When you install cams with longer durations the vacuum signal is reduced.
Better ignition curves and improvements to the fuel delivery is needed.
Only in the last year with vortec and msd has there been any improvements to the ignition curve. Now Big Gun has altered the curve to help in the more economical priced ignitions.
The RW ignition, without rev, has been the only prior ignition with an advanced curve.
My latest testing was the first time that we actually went over the top. That is, got too rich at very top(7000rpm up). Now I know the limits and can finish this project off.
Making the bore larger will be my next project. By design this is very limited. Lack of material and you can only bore in a limited area so as to not disturb the waves that control the slide and vacuum signal for fuel delivery.

 

OMR,

Aren't Mikuni's extinct except for Harley's now? Regulation is moving in on atvs and DS650 carb may be gone soon. Keinin 450r seems like the last great hope. Wouldn't your atomization and carb kit work for that as well? Honda/Keinin seems superior to me for only $170 and fits with stock DS manifold/filter and is not a cv or fsc but supposedly has characteristics of both AND is already a hot performer from the start. Like you said, the Mikuni is against the wall now so more effort may be fruitless in the same direction. I refuse to have a cv(other my stock duals for now) or a fsc if at all possible, but I very much would like to have one of your carb kits expecially if it had a dual tube atomization with 20-30% atomized fuel. Those carbs would smoke, get better gas mileage, and have tremendous response advantage over the excellent performance already. You're the expert so I'm sure you will have the best solution available. I can always put dually dialajet on 450r, but your solutions seemed more systemic utilizing all parts of the carb.


Thanks

 

yjacket2001,
When you talk about powerjets or dialajets I have only one statement to say.
They were invented for 2 strokes and/or as a vacuum accelerator pump.
There ability to atomize fuel is poor because of the location that they are mounted.
True atomization happens when raw fuel is drawn by negative pressure and when united with higher pressure, the sudden pressure change literally causes the fuel to explode into a fine mist. The lectron carb was designed with a flat on the backside of its jet needle to maintain the highest negative pressure, so that when the fuel came to the venturi it was in a very negative state. The excited fuel atomizes best under that system. Now you can understand why the lectron always makes more power when matched to a simular sized mikuni carb. I feel that the 42BSR can generate more power because of the poor atomization that was built into this carb for mass production.

 

Dave Moore racing has a super jet for alk that I offer on the site that is making more hp with a couple carbs. Take a look at it and let me know what you think cuz I installed a couple on my 20 mill shee and will be doing more testing in a couple weeks in the real world