CRF450R BIG BORE HELP!

DTHA70
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DTHA70
Edited Date/Time 12/15/2015 8:46am
Just installed a cylinder works 478 kit and a stage 2 Hotcam in an 09 CRF450R and degreed the cam got it right on the money.

Bike is incredibly hard to start now. Not hard to kick, just wont fire. Im thinking I need to add fuel at low RPM low Throttle%

anyone else with experience with a similar build?

Unfortunately unlike carbed bikes, EFI bikes don't pull more fuel through the same jet when you create more vacuum. So compensating for the extra volume needs to happen on a tuner which I don't have.
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KNIGHT104
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KNIGHT104 12/11/2015 2:22pm
12/11/2015 2:22pm
have you checked valve clearance? Maybe one or both intake valves are tight
DTHA70
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DTHA70 12/11/2015 2:24pm
12/11/2015 2:24pm
all valves, head, cam are all new. this thing was oil starved and everything but the trans and the cases got replaced.

Valves are on the money.
swedishfishmx
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swedishfishmx 12/11/2015 11:05pm
12/11/2015 11:05pm Edited Date/Time 12/11/2015 11:06pm
Timing is off? It should start even with a big bore. Maybe you are using the wrong currency?
rmstrg
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rmstrg 12/13/2015 9:40am
12/13/2015 9:40am
After I put a 270 kit and cams on my bike I had to get ECU remapped as it was extermly hard to start. Tokyo Mods did it for $50 and had it back in three days. The ECU is unaware that you have changed the fuel and air demands of the engine.

The Shop

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captmoto
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captmoto 12/14/2015 10:10pm
12/14/2015 10:10pm
DTHA70 wrote:
Just installed a cylinder works 478 kit and a stage 2 Hotcam in an 09 CRF450R and degreed the cam got it right on the money...
Just installed a cylinder works 478 kit and a stage 2 Hotcam in an 09 CRF450R and degreed the cam got it right on the money.

Bike is incredibly hard to start now. Not hard to kick, just wont fire. Im thinking I need to add fuel at low RPM low Throttle%

anyone else with experience with a similar build?

Unfortunately unlike carbed bikes, EFI bikes don't pull more fuel through the same jet when you create more vacuum. So compensating for the extra volume needs to happen on a tuner which I don't have.
Neither the motor people or Hot Cams offered mapping advice?
potatoflake
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potatoflake 12/15/2015 8:46am
12/15/2015 8:46am
DTHA70 wrote:
Just installed a cylinder works 478 kit and a stage 2 Hotcam in an 09 CRF450R and degreed the cam got it right on the money...
Just installed a cylinder works 478 kit and a stage 2 Hotcam in an 09 CRF450R and degreed the cam got it right on the money.

Bike is incredibly hard to start now. Not hard to kick, just wont fire. Im thinking I need to add fuel at low RPM low Throttle%

anyone else with experience with a similar build?

Unfortunately unlike carbed bikes, EFI bikes don't pull more fuel through the same jet when you create more vacuum. So compensating for the extra volume needs to happen on a tuner which I don't have.
captmoto wrote:
Neither the motor people or Hot Cams offered mapping advice?
Not surprising these days

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