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Dynojet problems, any help :)

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My buddy has a 450X here are the following settings:

Year: 2008 CRF450X

Elevation: 1211 ft

Temperature Range: 0C to roughly 25C

Smog (AIS): Stock

Airbox Modified Top: Snorkle removed

Airbox Modified Sides: Stock

Backfire Screen: Stock

Air Filter: TwinAir

Pilot Jet: Stock

Main Jet: CJ136 DynoJet

Needle: DynoJet

Needle Clip Position: 3rd from top

Fuel Screw Type: Stock

Fuel Screw Setting: 2 Turns out from seated

AP Modified: Stock

Leak Jet: Stock

AP Cover: Stock

Exhaust Type: Megabomb header with Q4 Slipon

Exhaust Modified: N\A

Pink Wire Modified: Stock

the problem is ever since installing the dynojet kit the bike won't run. At first he took it in for repairs and they said the "jet fell out" but woudln't tell us which jet. THen when it came back it ran great for one day, now it will not start again. after 45 minutes of trying to start it the spark plug was black and soaking wet, after cleaning it it started but spit out black smoke, then eventually fowls its plugs again.

We followed the instructions of the dynojet kit, but obviously it is crazy rich. The only problem is I am just learning how to do carbs (using this epic forum) but there doesn't seem to be a lot of support for dynojet and mostly yall use JD.

Any help would be awesome! Thanks for listening guys.


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You can't tell if a 4stroke is rich by looking at the plug.

You need to open the bottom of the carb and check for:

- crud in the pilot jet and the passage above it

- crud in the float needle

- loose jets (DO NOT OVER TIGHTEN!)

You have probably just flooded the engine.

With the kill switch pressed in, thottle held wide open, kick the bike 20 times to clear the cylinder.

Try starting again.

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Hello :thumbsup:

Thank you for the advice, we took everything apart again and the carb looked ok, turned out the wire attached to the spark plug had slightly ever so little worked it's way off and needed to be pushed on hard again.

Thnx for the help!

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