Super Jet Tuning help! running wayyy to hot

[cam_lg]

Welp looks like I welded some aluminum to my sparkplugs this weekend. Did some long WOT runs with what I thought was a decently tuned motor, and my plugs were Covered in in what looked like tiny black balls... Anyone have some tuning advise for me? Im running 38's with 75 low jet out 1 1/2, and 137.5 high jets 3 turns out. All in a ported 718 withwith C4 chamber. The builder I bought it from says he runs "1.5 n/s, 135 high jets, high speed screws 1 1/2 turns out, 70 low jets, low speed screw 1 1/4 turns out" on all his 718 builds, but it looks like I borderline fried my motor running higher jets and a 2.0 n/s

 

[cam_lg]

Update: with 36cc domes I'm getting 192psi in both holes... I should be getting under 180 with a ported 718 motor and 36's right?

 

[///M5]

Pistons and Domes look good. Not so sure where the deposits are coming from

 

[cam_lg]

Pistons and Domes look good. Not so sure where the deposits are coming from

^Thanks babe

 

[///M5]

^Thanks babe

At this rate, you need all the help you can get!

 

[cam_lg]

Anybody? I don't think it's an air leak, the motor only has 5 tanks through it.

 

[speedysprocket]

Why don't you think it's rich? And for future reference, if you think you need to open the high speed screw more than one turn, you need to go up in main jet size...

 

[///M5]

Why don't you think it's rich? And for future reference, if you think you need to open the high speed screw more than one turn, you need to go up in main jet size...

When we pulled those plugs we put new ones in and did a few chops. The NEW plugs were looking really white, and had hard deposits on the ground strap and plug base.

It was only at 3 turns while trying to diagnose the deposits.

 

[speedysprocket]

Well that would have been good to know. There comes a point where turning those screws out any further doesn't have any more effect. Go up a couple sizes and put those screws back in to a turn.

 

[///M5]

Yeah, thanks for the advice. That guy has to be more descriptive on his own thread.

I still don't understand where the hard deposits are coming from. The domes and Pistons are untouched (luckily).

 

[speedysprocket]

Looked like carbon, which is typically a sign of being rich.