No power

[Zac]

So I took my bike out today, and it wouldn't start, just made a loud POP like something breaking, I'm pretty sure it was backfiring. I swapped carbs, and did adjustments, and then when I put my old cylinder head back on, it fired up. But it drives slow. It idles nice, but just doesn't go fast and has no power. I did adjust the throttle cable a little and it made it a little bit faster, but I'm not sure what else to do. Any help?

 

[DieselTech]

Ok has this engine ran like this since out of the box? Or is it something that just started? You mentioned swapping cylinder heads, did you get a cnc billet head? Have you checked squish clearance yet? I feel squish clearance is the most important thing on these engines.

 

[Zac]

What is squish clearance?

 

[Zac]

Also if it doesn't go much when I give it gas could it be helped by running more lean or rich? I can swap jets and adjust the e clip

 

[Zac]

Looks like the jet my nt carb came with is a .60

 

[Zac]

Should I upjet?

 

[DieselTech]

Also if it doesn't go much when I give it gas could it be helped by running more lean or rich? I can swap jets and adjust the e clip

Ok can you pull plug & get me pics of plug? You want to error on the rich side, never the lean side.

 

[DAMIEN1307]

Looks like the jet my nt carb came with is a .60

Nope, NTs come stock with a 70.

 

[DieselTech]

Should I upjet?

Do you live in the mountains? What jets do you currently have?

 

[Zac]

I do live in the mountains. I'm just running whatever the nt comes with, apprently a .70. I can't get a good pic of my plug, it hasn't been used much, but the prong has dark oil on it