[joaoadias]

Hello to all,

I have a Honda CB 250 Nighthawk from 2001 and i'm doing some mods on it.

I now have the idea to adapt two carbs from other CB motorcycle, like the old school CB 250.

The carburetor that's on the bike ATM is the little original 26mm for both cylinders.

Did someone here ever did this adaptation? Is it worthy?

Thank you!

 

[longdistancerider]

I don't recall anyone doing this. Might start by looking thru parts fiches of different year 200/250 models to see what Honda may have done. Other option would be Mikuni carbs. You're going to be looking at mi to upper 20's in venturi sizing, 30's will be too much

 

[Oldgeezer]

I believe the performance gain is very little with twin carbs. I actually like the single carb on my CM200T as each cylinder gets the same mixture ratio & idle setting (single carb).

 

[joaoadias]

Thanks for your replies.

I feel like the engine is being strangled by that little carburetor.

After your opinions i should maybe opt by two 24mm carbs or something like that.

With the carbs i should swap those strangled mufflers with two smaller, unstrangled ones to help the engine breath better. What you think?

Is there any 2 in 1 throttle cable on the market or should i opt by a double carb instead of two separated ones?

Thank you very much for your Help!

 

[longdistancerider]

Split throttle cables are easy, any of the CB/CL/SL 350's or the CB/CL 450's.
Smaller muffler will make it louder but have no positive effect on the breathing, in fact they can make it worse. Look for muffler that are @1.25 Liters of volume and have the same size inlet and outlet of the actual pipes

 

[joaoadias]

I was thinking to get two of these mufflers from e-bay.

I already seen them on other CB 250's and they look good IMO.

https://www.ebay.com/itm/Motorcycle...ash=item28419ab321:g:KyUAAOSwoF1Z0VNG&vxp=mtr

Later, I'd like to chop the rear of the bike, and transform it on a scrambler

Thank You, João Dias

 

[joaoadias]

Or even 2 of these mufflers, they look nice too!

https://www.ebay.com/itm/Motorcycle...ash=item28419528dc:g:7PQAAOSwRsZZ0SkN&vxp=mtr

 

[longdistancerider]

The second one is the better choice. You'll have to add pacing to the muffler since they come with very little

 

[joaoadias]

I don't understand what you mean by add pacing.

Thank you anyways!

 

[longdistancerider]

Those mufflers have a fiberglass packing inside but very little of it. You remove the 3 screws that hold the end cap on and remove the baffle to wrap if with something like this https://www.amazon.com/s/?ie=UTF8&k...targid=kwd-313150027159&ref=pd_sl_tai6lkc1h_e
Muffler Repacking : FMF Racing

 

[Alan F.]

Hey joaoadias, any progress with your carb mods?