Converting The CB250 Nighthawk into a Cafe Racer! (Or at least how I did it)
This is not a project for the faint of heart. You will destroy your resale value, and frame cutting is required.
These instructions are for those with working knowledge of a motorcycle. Details on how to do certain standard modifications and removals are not given. With that said, lets get started
Parts Needed:
Older Model (Mid to late 70's) CB Fuel tank with left side petcock and NPT threading.
7/8" Clubman or 32mm clipon handlebars.
Cafe Seat (purchased or made)
Tail light and License Plate bracket
Bar end Mirrors (optional but adds to the look)
Two Shorty Mufflers or mufflers of your choice.
Two Vinyl Flooring Tiles (Explained Later)
Paint and Graphics if Wanted
Universal Headlight Ears (optional)
Universal Cafe 1/4 Fairing (optional)
Custom Made rearsets (Very Pricey Option)
Various Nuts, Bolts, Sheet Metal Screws and Spacers
Zip Ties
Shorty Shocks (11" Eye to Clevis)
New Chain and Sprockets of your choice (optional)
#38 Pilot Jet and a #115 Main Jet for carb
40mm Pod Filter (optional but great for rejet)
Construction paper and marker
Tools Needed:
Metric Socket Set
Metric Wrench Set
Screwdriver Set
Hack Saw (I told you we would be cutting)
Drill and bits
Sandpaper
Wire Cutters and Strippers
Motorcycle lift
Muffler Wrap (Optional)
Nerves of Steel :)
Instructions:
Start by Placing the bike on the lift and remove the Battery, handlebars, tank, seat, Plastic Body, exhaust system, turn signals, headlight and bracket (if replacing these), Rear Tire, Front and rear sprockets with chain (if replacing these), taillight, shocks, plastic fender, Carburetor and air box. With all of these removed, we can see that the potential actually is there to make this a sweet little Cafe, despite any ridicule we may have gotten.
Paint the tank and seat to desired color and graphics.
Next, cut the tail section just behind the upper shock mount weld and the front portion of the grab bar on both sides to leave a flat top frame. While we have the saw out, cut the exhaust just forward of the crossover pipe.
With the battery and air box out of the way, Use the construction paper and marker to make a template for new side covers. Place the construction paper behind the frame where the side covers are to go, and trace a line onto the paper to the shape wanted. Cut out the template, and transfer the design to the flooring tiles (told you I'd explain this). Using a box cutter, cut out the design on the flooring tile. Paint to match. Set aside for now.
Replace the front and rear sprocket (if replacing these), and reinstall the rear tire and chain. Install the 11" shocks.
Mount the new mufflers to the shortened exhaust. BTW, I painted my down tubes with high temperature exhaust paint. Replace the exhaust. Some brackets may need to be made Depending on your application so the exhaust does not rattle.
Remove the petcock from the stock tank and reinstall it on to the new tank. Slide the new tank in to place. Depending on your application, you may need to level the tank and make brackets or tie downs.
Install the Cafe Seat. Again, Depending on your application, Brackets may need to be made. (Told you this was not for the faint of heart!).
Loosen the bolts on the triple trees and push the forks up 1 1/2" to 2" making sure that they are they same level. WARNING! This will make your steering quicker and you will loose some give in you front suspension. This is necessary to level the bike after installing the shorter rear shocks. Tighten the bolts back down.
Install the new handlebars of your choice. Reroute the clutch, brake and throttle cables so that they do not bind. Install the bar end mirrors if you decided to go with this option.
If using the new headlight ears, install them on the forks but leave the a little loose for adjustments. Bolt the headlight to the ears and slide the headlight up and down the forks to the level that you want it. If installing the quarter Cafe fairing, leave room for it to clear you gauges. Install fairing.
Bolt the taillight of your choice to the tail section of the new seat and wire it up. Install turn signals in desired locations.
Install rearsets if you have them.
Rejet carburetor and reinstall. Place pod filter on carb if using this option. If not, reinstall air box.
Reinstall battery and check for power at all systems. Start the bike to ensure everything is set properly. Adjust accordingly. Zip tie anything that is hanging down (IE solenoids etc...) to the frame.
Using self drilling sheet metal screws and spacers, install the new side covers.
Another option is to relocate the battery so that it is under the hump of the new seat. This will required a base to be fabricated and welded to the frame and longer cables. If you do this, side covers are not required and gives a very clean look to the bike.
Another option is to use fuel cell foam to prevent to fuel from sloshing around in the tank. This is great for high speed turns.
Put on your best leathers and helmet, fire it up, and TON UP! Yes, with these mods, the 250 Nighthawk will do 100mph. With the new jets, air pod, more open exhaust, and different sprockets, it is more than possible. These mods removed 22lbs of weight from my bike and increased the HP to 31bhp (dynoed). Pretty trick, Huh?
Total cost of parts:
Tank: $50 - $100
Bars: $25 - $100
Seat: ? - $150 Depending on if you make or buy.
Taillight: $25 - $75 Depending on style used.
Mirrors: $25 - $150 Depending on style used.
Mufflers: $60 - $250 Depending on style used.
Flooring Tile :$1
Paint and Graphics: $25 - ? Depending on rattle can or professional and details of graphics.
Headlight Ears: $15
Fairing: $60 - $150 Depending on style used.
Rearsets: $$$$$$$$$$$$$
Shorty Shocks: $90
Chain and Sprockets: $130
Carb Jets: $7
Pod Filter: $10
Total Cost as I did mine : $668 for parts + $500 For bike = $1168.
More than half the cost of a new one, and three times as much fun!
This is not a project for the faint of heart. You will destroy your resale value, and frame cutting is required.
These instructions are for those with working knowledge of a motorcycle. Details on how to do certain standard modifications and removals are not given. With that said, lets get started
Parts Needed:
Older Model (Mid to late 70's) CB Fuel tank with left side petcock and NPT threading.
7/8" Clubman or 32mm clipon handlebars.
Cafe Seat (purchased or made)
Tail light and License Plate bracket
Bar end Mirrors (optional but adds to the look)
Two Shorty Mufflers or mufflers of your choice.
Two Vinyl Flooring Tiles (Explained Later)
Paint and Graphics if Wanted
Universal Headlight Ears (optional)
Universal Cafe 1/4 Fairing (optional)
Custom Made rearsets (Very Pricey Option)
Various Nuts, Bolts, Sheet Metal Screws and Spacers
Zip Ties
Shorty Shocks (11" Eye to Clevis)
New Chain and Sprockets of your choice (optional)
#38 Pilot Jet and a #115 Main Jet for carb
40mm Pod Filter (optional but great for rejet)
Construction paper and marker
Tools Needed:
Metric Socket Set
Metric Wrench Set
Screwdriver Set
Hack Saw (I told you we would be cutting)
Drill and bits
Sandpaper
Wire Cutters and Strippers
Motorcycle lift
Muffler Wrap (Optional)
Nerves of Steel :)
Instructions:
Start by Placing the bike on the lift and remove the Battery, handlebars, tank, seat, Plastic Body, exhaust system, turn signals, headlight and bracket (if replacing these), Rear Tire, Front and rear sprockets with chain (if replacing these), taillight, shocks, plastic fender, Carburetor and air box. With all of these removed, we can see that the potential actually is there to make this a sweet little Cafe, despite any ridicule we may have gotten.
Paint the tank and seat to desired color and graphics.
Next, cut the tail section just behind the upper shock mount weld and the front portion of the grab bar on both sides to leave a flat top frame. While we have the saw out, cut the exhaust just forward of the crossover pipe.
With the battery and air box out of the way, Use the construction paper and marker to make a template for new side covers. Place the construction paper behind the frame where the side covers are to go, and trace a line onto the paper to the shape wanted. Cut out the template, and transfer the design to the flooring tiles (told you I'd explain this). Using a box cutter, cut out the design on the flooring tile. Paint to match. Set aside for now.
Replace the front and rear sprocket (if replacing these), and reinstall the rear tire and chain. Install the 11" shocks.
Mount the new mufflers to the shortened exhaust. BTW, I painted my down tubes with high temperature exhaust paint. Replace the exhaust. Some brackets may need to be made Depending on your application so the exhaust does not rattle.
Remove the petcock from the stock tank and reinstall it on to the new tank. Slide the new tank in to place. Depending on your application, you may need to level the tank and make brackets or tie downs.
Install the Cafe Seat. Again, Depending on your application, Brackets may need to be made. (Told you this was not for the faint of heart!).
Loosen the bolts on the triple trees and push the forks up 1 1/2" to 2" making sure that they are they same level. WARNING! This will make your steering quicker and you will loose some give in you front suspension. This is necessary to level the bike after installing the shorter rear shocks. Tighten the bolts back down.
Install the new handlebars of your choice. Reroute the clutch, brake and throttle cables so that they do not bind. Install the bar end mirrors if you decided to go with this option.
If using the new headlight ears, install them on the forks but leave the a little loose for adjustments. Bolt the headlight to the ears and slide the headlight up and down the forks to the level that you want it. If installing the quarter Cafe fairing, leave room for it to clear you gauges. Install fairing.
Bolt the taillight of your choice to the tail section of the new seat and wire it up. Install turn signals in desired locations.
Install rearsets if you have them.
Rejet carburetor and reinstall. Place pod filter on carb if using this option. If not, reinstall air box.
Reinstall battery and check for power at all systems. Start the bike to ensure everything is set properly. Adjust accordingly. Zip tie anything that is hanging down (IE solenoids etc...) to the frame.
Using self drilling sheet metal screws and spacers, install the new side covers.
Another option is to relocate the battery so that it is under the hump of the new seat. This will required a base to be fabricated and welded to the frame and longer cables. If you do this, side covers are not required and gives a very clean look to the bike.
Another option is to use fuel cell foam to prevent to fuel from sloshing around in the tank. This is great for high speed turns.
Put on your best leathers and helmet, fire it up, and TON UP! Yes, with these mods, the 250 Nighthawk will do 100mph. With the new jets, air pod, more open exhaust, and different sprockets, it is more than possible. These mods removed 22lbs of weight from my bike and increased the HP to 31bhp (dynoed). Pretty trick, Huh?
Total cost of parts:
Tank: $50 - $100
Bars: $25 - $100
Seat: ? - $150 Depending on if you make or buy.
Taillight: $25 - $75 Depending on style used.
Mirrors: $25 - $150 Depending on style used.
Mufflers: $60 - $250 Depending on style used.
Flooring Tile :$1
Paint and Graphics: $25 - ? Depending on rattle can or professional and details of graphics.
Headlight Ears: $15
Fairing: $60 - $150 Depending on style used.
Rearsets: $$$$$$$$$$$$$
Shorty Shocks: $90
Chain and Sprockets: $130
Carb Jets: $7
Pod Filter: $10
Total Cost as I did mine : $668 for parts + $500 For bike = $1168.
More than half the cost of a new one, and three times as much fun!
Links for parts:
