Golden Spectro 155/45

[sether]

Jetting again :coocoo:

I'm running at 2500 -> 3500ft, airbox lid removed, uni, 155/45, Golden Spectro at 52:1 per the bottle, and my plug is black but not oily. No bog or hesitations. Temp is 98 degrees F. Terrain is desert with sand washes.

Should I move the needle clip or go 42 pilot?

Thanks :ride:

 

[John Harris]

Where is the needle clip now and is this a stock needle? Thanks John

 

[Rhodester]

I'd go 40 or 42 on the pilot and maybe a 152 (assuming stock pipe and reeds...leaner if aftermarket). That is also assuming that the temp stays around 98 degrees.

 

[sether]

Where is the needle clip now and is this a stock needle? Thanks John

Clip center (stock) position. Stock needle. Stock reeds. Stock pipe. No lid and UNI filter.

I mixed some Spectro today at 42:1 and did the same street testing and got a tan plug. Not black or dark brown. This is good. But, when I am pulling a long/deep uphill sand wash will it be to lean? Do I need dark brown to have a little extra rich to help under heavy loads? I don't want to seize it. :yikes:

Thanks

 

[John Harris]

On the stock needle most KDX run best on the next to the top clip. You may want to read some of the many threads on jetting here, but changing the ratio is not the way to jet. Going to 42 to one should be great for your KDX, but understand that this is a richer mixture than say 32 to one! Yes, less oil, but a richer burning mixture.
There are exceptions, but engines seldom seize at low speed and a leaner idle jet like 42 suggested will do wonders for your performance. If you are afraid of engine damage go bigger on the main until you are comfortable to reduce it. I agree with Rhodester above: 42 and 155 jets, second clip from the top and your 40 or 42 to one ratio should be great.
Every bike is different and read up on jetting here and jet yours for your use.
Ride safe John

 

[redramhemi]

Im running a 42/155 in a big bore 200, and the thing runs great. I had a 45 in it and it wouldnt idle when warm. change yours to the 42 , I think youll be happy with the results

 

[G. Gearloose]

If your so concerned about siezing it, why run 52:1? :coocoo:
GS won't want to hear from you if it frags.

 

[sether]

If your so concerned about siezing it, why run 52:1? :coocoo:
GS won't want to hear from you if it frags.

52:1 was just a test case. I ran 158/45 with GS 42:1 in the SoCal desert today for 4 hours, 9am - to 1pm, temps 80 to 102 degrees. Ran strong. Nice mix of fireroads, single track, and DEEP sand washes. I pulled the plug at home and had very dark brown. I think 155/42 would be the ticket or should I just move the needle to the second position? :ride:

 

[redramhemi]

158/45? Im surprised it ran in 102 degree heat, definitely not as strong as you think (or it should) REJET YOUR BIKE< youll be happy you did

 

[Green Hornet]

In severe conditions Spectro recommends 40:1. I think your riding conditions qualify as SEVERE :ride:

 

[sether]

158/45? Im surprised it ran in 102 degree heat, definitely not as strong as you think (or it should) REJET YOUR BIKE< youll be happy you did

OK, as soon as UPS brings me the 42 I'll go 155/42. :nod:

Also, I weight 210lbs so maybe I need it to run richer than some folks? :think:

 

[Jackpiner57]

Just remember that a 40:1 as opposed to a 52:1 mix will make the fuel mixture leaner. So if you go to the 40:1 mix you might not need to go to a smaller jet, or at least not as small of a jet. Try it , then if that doesn't work you can go down one jet size at a time until you get it right. Use a new plug for each change.

 

[Rhodester]

I'm 230lbs and don't need to jet rich for my weight. 155/42 will get you closer to the ball park.

The area around the tip of the plug tells you about the heat range you're running. It also reflects on the fuel additives in the gas. The area at the extreme bottom of the insulator tells you about the jetting.

 

[sether]

I'm 230lbs and don't need to jet rich for my weight. 155/42 will get you closer to the ball park.

The area around the tip of the plug tells you about the heat range you're running. It also reflects on the fuel additives in the gas. The area at the extreme bottom of the insulator tells you about the jetting.

I noticed your in Idaho. Want altitude are you at?

Thanks