Jetting

[jwood99]

Wondering what would be recommended for jetting, ive put in a y-pipe, pipe, billet head and jc custom vent kit on my 09 summit 800.

Thanks

 

[thorrider11]

I would just go to 470 mains

 

[takethebounce]

Wondering what would be recommended for jetting, ive put in a y-pipe, pipe, billet head and jc custom vent kit on my 09 summit 800.

Thanks

Who's head did you put in? What compression? Usually any repuatable mod company has recommendations for any req'd jetting changes.

The y-pipe and pipe alone shouldn't require any jetting changes, atleast most off the shelf companies like Dynoport and such don't require it. The vent kit has little to no effect.

The rest lies in the head, compression, fuel you run and what altitudes you ride at.

 

[jwood99]

terra alps head, with 12.5 domes

 

[takethebounce]

terra alps head, with 12.5 domes

isn't the stock motor 12.2 or 12.3? 12.5 is hardly a difference.

 

[pistonbroke800]

That compression is pretty much stock. I wouldn't change anything. DPM will easily adjust for that tiny compression increase.

 

[takethebounce]

Well not exactly, the DPM won't know that you have done anything to the motor.

The DPM is able to lean out the fuel system, but not richen it. It works by adjusting the float bowl pressure to change how much fuel is delivered by a vaccum.

The jetting is set to be the safest for all possible conditions, then as temperature changes, engine timing, knock sensors and everything else controled by the ECM allow the DPM to vary the pressure.

 

[DaveB]

Stock jetting should be fine. I don't believe Terra Alps runs a super tight squish band like an RKT, so jetting down is not required. You'll still get the benefit of a hemispherical combustion chamber vs. the stock bathtub design.