Honda Rebel 250 & 450 Forum banner
1 - 20 of 22 Posts

· Registered
94 Nighthawk CB250 (Big Bore 275cc)
Joined
·
44 Posts
Discussion Starter · #1 ·
Researching BB kits in general, I found that more "complete" kits include a cam that was ground to better match with the added displacement squeezing out an extra HP or 3 in the process. My Ebay blue light special BB kit did not include a cam. Can a qualified shop re-grind my cam just based on the change in displacement? Is it a simple formula "x amount of added cc's = x amount of extra duration on the int/exh" , or a bit more trial/error involved? Much thanks in advance for any input as always!
 

· Registered
94 Nighthawk CB250 (Big Bore 275cc)
Joined
·
44 Posts
Discussion Starter · #5 ·
Do you have a link for the kit?
I do! Same seller I got mine from this time last year, though seems to be shipping from CA now, not china. The jugs are clearly from the chinese Rebel/CB250 clone, quality seemed good enough though. Hasnt grenaded on me yet going on a year : )
 

· Registered
94 Nighthawk CB250 (Big Bore 275cc)
Joined
·
44 Posts
Discussion Starter · #6 ·
I do! Same seller I got mine from this time last year, though seems to be shipping from CA now, not china. The jugs are clearly from the chinese Rebel/CB250 clone, quality seemed good enough though. Hasnt grenaded on me yet going on a year : )
 

· Registered
Joined
·
103 Posts
I do! Same seller I got mine from this time last year, though seems to be shipping from CA now, not china. The jugs are clearly from the chinese Rebel/CB250 clone, quality seemed good enough though. Hasnt grenaded on me yet going on a year : )
Thanks for the link :D
How many miles do you think you have on the kit?
Also can you feel the power difference?
 

· Registered
VTX 1800, Rebel 250's and 450's, CB1300
Joined
·
540 Posts
I ordered the BBK as well, and am still in await of receiving it. Should be here any day now.
I'm gonna run the standard cam, standard 1st Gen carb with upped jets of course.

And I already have a 2-in-1 system with a loud damper.
Here in Europe, we have the SMC Barossa and RAM quads which use a rip-off of the CMX250 engine, and they fit a 2-in-1 system that kind of directly bolts onto the Rebel.
 

· Registered
94 Nighthawk CB250 (Big Bore 275cc)
Joined
·
44 Posts
Discussion Starter · #10 ·
Thanks for the link :D
How many miles do you think you have on the kit?
Also can you feel the power difference?
I'd say around 5k, power difference felt ALL around! Not a dramatic difference, BUT not a suddle difference either if that makes any sense. The gains arent felt off the line, but more when taking on headwinds, inclines, passing. Before... I sadly couldnt even pass a schoolbus letting me by.. literally! Now, its not so much an issue anymore, lol! I should also mention 57.4mm pistons appear to be common standard, one could easily have their existing jugs honed out for the larger pistons, no need for kit.
 

· Registered
94 Nighthawk CB250 (Big Bore 275cc)
Joined
·
44 Posts
Discussion Starter · #11 ·
I ordered the BBK as well, and am still in await of receiving it. Should be here any day now.
I'm gonna run the standard cam, standard 1st Gen carb with upped jets of course.

And I already have a 2-in-1 system with a loud damper.
Here in Europe, we have the SMC Barossa and RAM quads which use a rip-off of the CMX250 engine, and they fit a 2-in-1 system that kind of directly bolts onto the Rebel.
I look forward to you doing the mod! Please do report back on how you dialed the carb in, thats sadly one thing I havent fully figured out yet. Im a touch on the rich side still. Dont forget a hi-flow air filter, sport cdi, & iridium plugs if possible! Im still debating as to whether or not HD clutch springs are necessary as well, if the plan is to run the bike hard its strongly recommended.
 

· Registered
VTX 1800, Rebel 250's and 450's, CB1300
Joined
·
540 Posts
I'd say around 5k, power difference felt ALL around! Not a dramatic difference, BUT not a suddle difference either if that makes any sense. The gains arent felt off the line, but more when taking on headwinds, inclines, passing. Before... I sadly couldnt even pass a schoolbus letting me by.. literally! Now, its not so much an issue anymore, lol! I should also mention 57.4mm pistons appear to be common standard, one could easily have their existing jugs honed out for the larger pistons, no need for kit.
Correct, the pistons are widely available.
 

· Registered
VTX 1800, Rebel 250's and 450's, CB1300
Joined
·
540 Posts
I look forward to you doing the mod! Please do report back on how you dialed the carb in, thats sadly one thing I havent fully figured out yet. Im a touch on the rich side still. Dont forget a hi-flow air filter, sport cdi, & iridium plugs if possible! Im still debating as to whether or not HD clutch springs are necessary as well, if the plan is to run the bike hard its strongly recommended.
My plan is to use all the original parts to run the engine.

You say, run a different CDI? Please tell more or show what you have?
 

· Registered
94 Nighthawk CB250 (Big Bore 275cc)
Joined
·
44 Posts
Discussion Starter · #14 ·
My plan is to use all the original parts to run the engine.

You say, run a different CDI? Please tell more or show what you have?
I cant tell you how much of a dice roll it felt when buying this unit, I had tried the cheapo amazon "perf cdi's" with poor results, not to mention the website markets it as "OEM Style" . I can safely attest it is in fact a slightly hotter CDI, redline is higher and gets there quicker, also disables the kickstand kill switch which I find quite nice ; )

 

· Premium Member
1985, 86 CMX250C, 81 CM200T, 74 CL360, Invisible to cages, treat them accordingly. Avoids Road RAGE!
Joined
·
4,067 Posts
Thanks for posting this. Finding replacement CDIs that actually work has often been a struggle for many.
 
  • Like
Reactions: JSJJ388

· Registered
94 Nighthawk CB250 (Big Bore 275cc)
Joined
·
44 Posts
Thanks for posting this. Finding replacement CDIs that actually work has often been a struggle for many.
I feel that whole heartedly! Hence, why I didn't mind spening extra for that unit, long as it worked I said. My stock unit was still good when I got the Ricks CDI so I was able to A-B test them and confirm Ricks CDI is higher performance. My speculation with the Ricks products is that the Black units are exact OEM & the orange ones are the performance series. Now oddly enough, my stock CDI recently died on me, rather sudden too. I wanna build some pannier style boxes, and load them with some 4x10 speakers and amp/battery down the line, so I will likely give their high output rectifier a shot as well.
 

· Registered
VTX 1800, Rebel 250's and 450's, CB1300
Joined
·
540 Posts
I feel that whole heartedly! Hence, why I didn't mind spening extra for that unit, long as it worked I said. My stock unit was still good when I got the Ricks CDI so I was able to A-B test them and confirm Ricks CDI is higher performance. My speculation with the Ricks products is that the Black units are exact OEM & the orange ones are the performance series. Now oddly enough, my stock CDI recently died on me, rather sudden too. I wanna build some pannier style boxes, and load them with some 4x10 speakers and amp/battery down the line, so I will likely give their high output rectifier a shot as well.
Specify 'high output' ?
You have a link?
 

· Premium Member
1985, 86 CMX250C, 81 CM200T, 74 CL360, Invisible to cages, treat them accordingly. Avoids Road RAGE!
Joined
·
4,067 Posts
disables the kickstand kill switch which I find quite nice ; )
Disabling the kickstand safety switch isn't necessarily a good idea. Crashing can & has occurred when the kickstand is forgotten & left down. I can personally attest to the extreme dangers of this, as well as the cost for life flight. If your Rebel had it to start with, it is wise to leave it intact.
 

· Registered
94 Nighthawk CB250 (Big Bore 275cc)
Joined
·
44 Posts
Discussion Starter · #19 ·
Disabling the kickstand safety switch isn't necessarily a good idea. Crashing can & has occurred when the kickstand is forgotten & left down. I can personally attest to the extreme dangers of this, as well as the cost for life flight. If your Rebel had it to start with, it is wise to leave it intact.
I right with ya there on being as safe as possible, however on the Nighthawk 250 it has a HUGE dummy light for the kickstand which is more than enough for me. Disabling the killswitch just saves me looking like an ass from time to time when I forget its down. I see the light and the stand is up before the clutch is feathered into 1st.
 
1 - 20 of 22 Posts
Top