[nema741]

Coming along nice!!! If my 170 4V koso blows I’m doing this next. Are you going to run the aracer? How well does the CB engine harness mate with the factory Grom chassis harness. Or do you utilize both?

I have contemplated the Aracer, but now that I've really gotten a hang of the Bazzaz I just cant justify the swap. The harness compatibility is so - so... You can make this swap as easy or more work for yourself depending how you get your piece parts. Basically if you have a donor bike you can use the left/right handlebar controls which cuts out a decent amount of splicing. It's really not hard at all. As long as you have the proper wire diagrams for both bikes it's very easy to figure it out.. It's essentially the same as adding a "aftermarket" set of blinkers to a bike that doesn't utilize the factory plugs. The wire harness I have for the CBR also came with the fwd portion that connects to the signals, head light etc. All in all, i'm hacking up my grom harness and will use those to extend / adapt the lights.

It's all about finding proper home for the CBR harness on the grom frame. I basically started with the voltage regulator and the ECU, then everything just kind of fell into place (as far as the motor sensors, throttle body, fuse box). The rear tail lights will be fairly simple. I'm also using the grom ignition adapted to the CBR harness. which grom is 4wire, and cbr is 3 wire (only 2 wires shown on schematic w/ a pink security wire) which you only need 2 of the grom wires as there are (2 internal switchs) on grom ignition. I will have to extend the ignition wires to reach the CBR harness plug. The way I have the harness mounted the ignition plug is under the fuel tank. and grom's is located in headset area

 

[maz_636]

Will be following this thread closely so dont miss out any details haha !

 

[AvR]

Do you think you will have clearance issue with the radiator and max left or right steering input?

 

[nema741]

Do you think you will have clearance issue with the radiator and max left or right steering input?

No clearance issues, fits just right. If you can see where I currently had the coil pack bolted at the radiator will be getting tucked up under there which still fits between the fairings and allows enough room not to hit forks on full swing left/right. I'm using the stock CBR250 Radiator. I do need to get heater hose from the parts store thought to accommodate the radiator sitting up a few inches higher.

 

[nema741]

I am also utilizing my Grom Bazzaz Unit. All the Bazzaz units are "identical" it's just the wiring harness + supplied fuel map that is different between each unit. Bottom line is you just need to tap into the bikes TPS, CKPS, Neutral wire, Speed Sensor, Injector and +12V/Ground.

 

[CiscoSanJose]

Great write up, I want to go 300cc just for the water cooled engine and 6 speed transmission so the 250cc is similar. Finding a killer deal on a donor 250-300cc is the trick

 

[nema741]

Great write up, I want to go 300cc just for the water cooled engine and 6 speed transmission so the 250cc is similar. Finding a killer deal on a donor 250-300cc is the trick

Thanks! I've got a Microsoft "word" document that I've been documenting everything in, pictures, instructions etc. Trying not to put out all of the instructional portions until I've got it completely verified and running. One thing I am thankful for is going to a tech school for electronics, it significantly helps when bouncing back and forth between harness's, schematics, performing wire checks etc. Hopefully this will take away from the mystery of performing these swaps. I couldn't believe after all the research I did prior to jumping into this to find very minimal info on the way to do this..

Some Component info:
Compatible Shifter MSR 34-2138 for a KDX/KX has the perfect bend radius and eliminates the stock shifter and hinge bracket.
Rear Sprocket JTR 279-30 is a 520 Series sprocket to match the CBR's. You can order a sprocket for a CM250/CMX250 sprocket sizes from 30-36. If you look on JT Sprockets website as long as you use the JTR 279-** designator you can get whichever size sprocket your looking for. Use the ** to insert your sprocket size.

 

[CiscoSanJose]

Thanks! I've got a Microsoft "word" document that I've been documenting everything in, pictures, instructions etc. Trying not to put out all of the instructional portions until I've got it completely verified and running. One thing I am thankful for is going to a tech school for electronics, it significantly helps when bouncing back and forth between harness's, schematics, performing wire checks etc. Hopefully this will take away from the mystery of performing these swaps. I couldn't believe after all the research I did prior to jumping into this to find very minimal info on the way to do this..

Some Component info:
Compatible Shifter MSR 34-2138 for a KDX/KX has the perfect bend radius and eliminates the stock shifter and hinge bracket.
Rear Sprocket JTR 279-30 is a 520 Series sprocket to match the CBR's. You can order a sprocket for a CM250/CMX250 sprocket sizes from 30-36. If you look on JT Sprockets website as long as you use the JTR 279-** designator you can get whichever size sprocket your looking for. Use the ** to insert your sprocket size.

Same here,high school electronic nerd and auto-shop geek, electronic Technician when I was in the Navy, IT specialist Government contract jobs when I got out of the Navy, doing network design, computer design, computer security, WAN and satellite and line of sight communications.

 

[funcoland]

Great job nema, looking forward to the end result!

I am on the fence with this swap because I feel like I can easily turn a wrench to figure out where all the hard bits go and plug in.. but I'm only intimidated right now with the electrical stuff.

 

[nema741]

Got a lot of wiring done yesterday. I chose the route of keeping all of my grom controls (right hand - dimmer switch, turn signal, horn, clutch switches) and (left hand engine on/off, start & front brake light switch), I still have to finish up the (front head light & turn signal harness), and the rear tail light plug. What I did was located all of the groms harness plugs and removed necessary portions of loom/electrical tape etc to allow me to cut the groms harness plug off and provide enough wire to reach the new locations. The way my CBR harness sits on the bike, the control plugs are under the fuel tank area and required to be extended approx. 12" to reach the steering stem area where the groms control plugs sit.

I started with the ignition, the grom is 4 wires, the CBR has 2 wires plus a "pink" wire for security purposes that requires 9v to allow the fuel pump to come on. I cut the grom harness plug for ignition out, and removed the R/Y & Bl/R wire as it's not required to adapt to the CBR. Now I connected the remaining R and Bl/Y wire to the CBR harness wires (I removed the CBR ignition plug from harness) then connected the grom wires to CBR R/W & Bl/R. ( I will provide a spreadsheet that shows all the conversion of which wires goes to each other from cbr to grom). Additionally I tapped off the CBR's Bl/R wire (which is +12V) and added a zener diode that reduces the voltage on the output of diode to +9v and then connected that to the pink wire on CBR harness (note: pink wire on cbr harness is not shown on schematics!!).

Now to test it. Turned the key on and wallllaaaaa, the cluster lit up to life and ignition worked properly!

 

[nema741]

You can eliminate the need for a lot of the custom wiring by using the CBR left / right controls! But if you can follow simple instructions, know how to use a solder iron it's not difficult. All of my connections are spliced together, soldered and then heat shrinked.

 

[nema741]

You can eliminate the need for a lot of the custom wiring by using the CBR left / right controls! But if you can follow simple instructions, know how to use a solder iron it's not difficult. All of my connections are spliced together, soldered and then heat shrinked.

Note: I will provide all the wiring converstions as I finish my connections and verify everything works as it should. There has been a few wires that I was able to eliminate that the grom used vs the cbr does not as it splices in someplace else on the harness to provide the power to certain items. I.E. on the right hand controls the horns black wire was the +12V for the horn, and additionally it was spliced off and provided common power to the groms parking lights which on the CBR harness the parking lights were powered from a brown wire that was directly off the main ignition (vcc) source elsewhere on the harness, allowing me to eliminate the O/W wire and the Lb/W from the right hand control 14pin plug.

 

[funcoland]

You can eliminate the need for a lot of the custom wiring by using the CBR left / right controls! But if you can follow simple instructions, know how to use a solder iron it's not difficult. All of my connections are spliced together, soldered and then heat shrinked.

Note: I will provide all the wiring converstions as I finish my connections and verify everything works as it should. There has been a few wires that I was able to eliminate that the grom used vs the cbr does not as it splices in someplace else on the harness to provide the power to certain items. I.E. on the right hand controls the horns black wire was the +12V for the horn, and additionally it was spliced off and provided common power to the groms parking lights which on the CBR harness the parking lights were powered from a brown wire that was directly off the main ignition (vcc) source elsewhere on the harness, allowing me to eliminate the O/W wire and the Lb/W from the right hand control 14pin plug.

Yeah I guess it doesn't seem too bad if you take it slow and carefully, and of course know which wires go where. Did you go through and connect the wires one at a time and turn on the power to make sure that it's the right wire you are in?

That's probably what I would do, step it 1 by 1.

Btw, earlier you mentioned you had ignition .. does that mean you were able to turn the starter or did the actual engine turn over?

 

[nema741]

Yeah I guess it doesn't seem too bad if you take it slow and carefully, and of course know which wires go where. Did you go through and connect the wires one at a time and turn on the power to make sure that it's the right wire you are in?

That's probably what I would do, step it 1 by 1.

Btw, earlier you mentioned you had ignition .. does that mean you were able to turn the starter or did the actual engine turn over?

Yeah I turned ignition on, clusters powered, parking lights were on, and turned over the motor (I don't have fuel tank on so no start yet)

 

[maz_636]

Definitely getting close then! Cant wait to see it going, youll need to record the first start up and stick the video up!

 

[funcoland]

What are you using for cooling btw? Is it just the radiator and fan that come with the engine from the factory?

 

[nema741]

What are you using for cooling btw? Is it just the radiator and fan that come with the engine from the factory?

Yes stock CBR250 radiator and fan. On the right side of engine I am using a piece of standard heater hose as the stock hose didn't quite reach where I'm locating the radiator. On the left side hose I was able to use the stock hose and just cut a few inches off so it lined up perfect.

 

[3sexy5u]

Crazy fast progress. Seems like I am always waiting for that last piece for my 170 build. Can't wait to see her fired up.

 

[nema741]

Here is location of the cbr harness plugs that I cut and wired up the grom plugs


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[nema741]

This is the grom harness I was stripping down to use the harness plugs on cbr harness. Nothing To be scared of! Working with both schematics and I made cross reference spreadsheet that I more than double checked what each wires function serves.


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