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2012 cbr help

2119 Views 21 Replies 6 Participants Last post by  itismeman
Hi I recently bought a 2012 Honda CBR250 and my partner and I found out that the frame was completely damaged in the front after we brought it home. But the bike was running mechanically perfect just cosmeticly and the front tire was hitting the frame of the car. So we made the choice to swap out the old frame with another frame, 2012 Honda CBR300. Everything moved over fine and I believed we hooked up all the components correctly, but now when we try and start it. It doesn’t do anything, no lights, nothing turns on or the engine doesn’t even make a clicking sound like it was going to turn over like a car does (if motorcycle engines do that as well, idk this is my first motorcycle ever, also this was my first time swapping a engine over. I didn’t do this all by myself I had my partners step dad come and help us who he knows a lot about doing that kind of things)
But I am charging the battery right now to see if maybe the battery died and I’m going to see if that doesn’t fix the problem. But please if anybody has any ideas or has swapped over a engine from one bike to another bike. Please let me hear your stories/ideas/experiences so that I can check with my bike to see if I might have missed something because right now I am at a lost for words.
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You have to also swap over:
  • wiring harness
  • ECU
  • all sensors
  • anything and everything attached to engine
what you want to do in end is swap frames, not just engine.
We did and still nothing any way we can communicate threw FaceTime or phone call. I’m a 30 year kid who knows nothing about bikes in California
Also I’m in Walnut Creek ca
Hi I noticed that you live in the Bay Area as well any way if your free I would gladly pay you for your time if you are able to come and look at it
Might be possibility to visit. Let me check schedule this next week.


Measure all fuses. Don’t just look at then, connect meter and measure resistance between legs.

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Sweet want my cell number that would be awesome
I take it you also swapped over ignition switch? It’s matched to ECU
Sorry I have no idea how to help but I also have a 2012 cbr250 and I live in walnut creek if you ever want to go for a ride sometime once youre back on twos
Yeah totally I sent my number is a private message
I take it you also swapped over ignition switch? It’s matched to ECU
Did you do this?

This is why we keep Danno around...
Yeah so you know him too and yeah I did
Yeah idk something else is wrong
It may seem too simple, but is the earth lead from the battery actually connected back to the motor? Also, have you tested for battery voltage at various connectors along the wiring loom?
Did you get my text? I can take this afternoon off to fix it for you. Just cover my wages for afternoon. One flat-rate no matter how long it takes. Guarantee you'll have running bike when I'm done.
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It may seem too simple, but is the earth lead from the battery actually connected back to the motor? Also, have you teat d for battery voltage at various connectors along the wiring loom?
You know, that's good point. I made this mistake one time many decades ago. Guess where power to starter will get its ground? Through any other earthing point! That means through harness wires and it'll fry them!

On certain Porsches, if you don't have good ground to starter, starting current will go through ECU and fry it!

In this case, I think it's just matter of going through wiring-diagram and verifying everything's connected properly by measuring with multimeter. Could be earth side of interloc safety switches. Could be power side to switches and relays. There's about 5 steps to get power to starter-solenoid and any one of them being wrong can prevent starting.
The clutch and kickstand switches are very weak on these bikes. Just removing them to transfer to another bike can often break or cause them to fall apart. Test all safety interloc safety switches:

1. key ON. Shift bike to neutral. Does neutral light on dash turn ON?

2. disconnect wires from clutch switch and measure resistance/ohms between switch terminals.
a. What is resistance with clutch lever released/OUT?
b. What is resistance with clutch lever squeezed/IN?

3. disconnect wires from kickstand switch and measure resistance/ohms between switch terminals.
a. What is resistance with kickstand up?
b. What is resistance with kickstand down?
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@Johnfielding2018

Learn how to use multimeter to measure voltage, resistance and perhaps even current.


I assure you, you will NOT get this bike running without learning how to use multimeter. Then measure:
  • measure battery voltage with bike OFF
  • key ON, measure battery voltage when pushing start button.
This data will go a long way towards getting bike working. Actual measured numbers says tonnes; way more than words or pictures.

For example, you’re riding down road and bike sputters and dies. You push start-button and it cranks and cranks, but never starts. You call for help and they ask you, ”How much gas do you have in tank?”.

Then you send them picture of gas-cap on tank. Not as useful as saying:

”It’s got 1/2 tank showing on gauge” or
”I just put 15 liters in just 5-minutes ago.”

So get multimeter, learn to use it, measure stuff requested above and post it here. This is literally a 5-minute repair with multimeter!!!
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