[Bigdave450r]

Hey guys my 450 bogs at full throttle put new fuel filter and air filter. It’s 100 percent stock. But when I first start it up and go for a ride it runs good and strong but after a few mins it starts doing it again anyone know the problem?

 

[Dust Devil]

Welcome to the forum...!!!

What do you mean by fuel filter..?? There's a fuel strainer in the fuel pump. see pic

Make sure the battery is fully charged, 12.8v standard..!

Make sure there's a little slack in the throttle cable..!

Is it hard to start when the engine is hot..???

Does your F.I dash light (far left) remain on or flashing when engine is running...???

 

[Bigdave450r]

Yes the little strainer and battery good and some slack no starts right up and the lights off when riding

 

[Dust Devil]

Yes the little strainer and battery good and some slack no starts right up and the lights off when riding

Can you check the valve clearance..?
Valve Clearance: between cam and valve lifter
Standard:
Exhaust 0.17 ∼ 0.22 mm (0.0067 ∼ 0.0087 in.)
Inlet 0.10 ∼ 0.15 mm (0.0039 ∼ 0.0059 in.)
If the valve clearance is not within the specified range,
adjust it.

Here's a video to help

 

[Bigdave450r]

Sometimes it runs good and strong full throttle and imma have to send it to a mechanic to do that

 

[Melman]

It sounds like it may be losing fuel pressure. Add "checking the fuel pump and regulator" to your mechanics list.

 

[Bigdave450r]

Still bogging but more at full throttle, just put new fuel pump and still the same what u guys think?

 

[Dust Devil]

Still bogging but more at full throttle, just put new fuel pump and still the same what u guys think?

Make sure your battery is fully charged 12.8v standard...test your stator's charging see pic

Check your throttle positioning sensor to be in range...

Again check your valve clearance, might be the valves floating at higher RPMs due to being too close...!!!