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951
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7/21/2016
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Houston-ish, TX
US
Picked up a fresh Honda CRF 450 a few weeks ago. Have been enjoying it so far, with one issue that is still bugging me: when rolling the throttle on the engine feels very abrupt/jerky. Feels like a badly jetted 2-stroke that is surging.
This is mainly a problem in flat turns and rutted corners; places where a smooth throttle hand is important.
I have turned the idle up quite a bit and that helped some. Primarily have adapted by giving bigger throttle openings and feathering clutch more.
Have read that remapping (send off or DIY) will help. Have also read that some exhausts will help. Any others have this problem and potential solutions?
This is mainly a problem in flat turns and rutted corners; places where a smooth throttle hand is important.
I have turned the idle up quite a bit and that helped some. Primarily have adapted by giving bigger throttle openings and feathering clutch more.
Have read that remapping (send off or DIY) will help. Have also read that some exhausts will help. Any others have this problem and potential solutions?
Also just a note, if youre riding a bike too slow for the gear it can get jerky. I experience this on my street bike if a car is dropping anchor lol.
Paw Paw
This sensitivity happens in all gears and is worse in lower gears (harder lurch in 2nd vs 3rd). It's almost as if it is tuned to be ultra responsive, but for a bike with this much power, it's not really a benefit (IMO).
TokyoMods was top on the list for remap.
Have the same issue, has anyone found a solution?
The Shop
I checked the TPS closed voltage, it was set at 0.48volts. I moved it to .5 volts in an effort to improve it but nothing changed.
I built the DIY tool and bought the Fuel Injection CD from Honda, both described in this thread : https://www.thumpertalk.com/forums/topic/1071987-10-pgm-fi-hrc-tuner-to…
I then updated the mapping (stock maps on left, mod maps on right)
:
The difference was pretty dramatic. The reduced ignition timing and more fuel at small throttle openings got rid of the herky-jerky throttle sensitivity. The revving out was also better with the added fuel.
If I remember right, Map1 was hard coded and couldn't be changed, Map2 was the MX map, and Map3 was the torquier/off-road map.
I had an 18 with this exact problem. An akrapovic full system fixed it for me.
Different bike - same feeling.
Vortex ecu and akrapovic took 95% of it away for me on a Mc350f.
finding those parts used for yours is a good investment.
I made a post about my FC350 and the same thing. Removing the cone out of exhaust helped some and Vortex was dramatically better.
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