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250r Engine Swap: In progress!

844 Views 13 Replies 6 Participants Last post by  Ghost56
Im swaping the engines out this weekend.
I dropped the engine on the grom and have it all ready for the CBR250r Engine.
Ill post some pics, its going quite well.
I removed the Grom engine no problem, working on the CBR now but the last bolt on the CBR250R Engine frame is giving me tons of issues.

Last bolt is still fighting me, but I worked around it.
Dropped the engine and removed the electrical harness.
Will post some more pics throughout the weekend

Thank you
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Engine removed from the CBR, just need to take out the radiator parts.
Im going to changed out the plugs before I mount the engine.
Im painting the engine mount brackets now

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Got the Engine in, did this by myself.
It was rather difficult doing this part along, I would recommend getting a buddy to help
working on the wiring now but will prob have to make a separate post as I cant quite figure out what to do with 2 wires
Once the block off for the air injector delete is installed what do I do with the 1 remaining cable connector? Just leave it?
and on the other side of the bike, I cant for the life of me figure out what this connector is for?

Otherwise I have all the cables connected just to get an idea of where they need to go before I start ziping things down.
I still need to install the gas tank and do the mod for the fuel line injector cable, but todays goal was the Engine mount and dry hookup for the wire harness

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Duh ok figured that one out, been in the garage prob too much today

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Update, will add more details..
Big shout out to wicked grom

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Very nice! I'm looking to do a similar swap on mine. Cool pics of the progress
I’m in the middle of one too. The wiring has me stumped
I’m in the middle of one too. The wiring has me stumped
What part are you stuck on for the wiring?
I have most of that part completed now.
Im currently working on extending the fuel line and installing the radiator.
Next will then be the sprokets and chain and then I should be good to go.
Im waiting for a few parts to come in from Amazon and steady garage
I used the CBR harness and as many parts as I could from the CBR

Here is a link and thread to alot of wiring info:
CBR-Grom Swap Guide.pdf
Build #2 - CBR 250 Swap

You can also buy a full wire conversion kit here and save the headache:

Ill post some more pics over the weekend
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In one photo I saw you holding what looked like the CBR ECU, I hop you don't plan on using it because it will run like ass, and maybe not even idle.
In one photo I saw you holding what looked like the CBR ECU, I hop you don't plan on using it because it will run like ass, and maybe not even idle.
Thats the Grom ECU.. Im going to use it temp until I get an aftermarket one
Im just waiting on a few more parts and then I should be done.
Harnes is down, connected and extended in places that it needs to be
I extended the fuel line
Spockets swapped 15/32
New Chain
New fairings came in as well.

The last part arrives Wed so I should be done by next weekend
Ill post some pics
Thats the Grom ECU.. Im going to use it temp until I get an aftermarket one
The Grom ECU won't work on a CBR 250/300 motor.
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