426, Need input

[sprtrx300ex]

I will be installing a new 426 motor with 11:1 compression. Im gonna run stock oil tank, white brothers r-4 slip-on, and stock carb with removed airbox lid. elevation is around 300ft


What type of oil, and size jetting should I run. any other info is appriciated

[TC426EX]

Youll want to run a 50w oil for sure, and as far as the jetting with the slip on, Im not sure. I would start at a 175 and go from there

[sprtrx300ex]

After reading other threads, I put in a 155 main jet with 42 pilot, 2 1/4 turns put on the fuel screw. Im going to run Honda GN4 20-50w oil. My airbox lid is off, so Im not sure if the 155 is going to be too lean.

Oh by the way Im going to run 94 octane gas from Sunoco on the 11:1 compresson.

ANy opinions ?? Im open to everything!

[TC426EX]

get a couple new plugs and do a plug chop. That way you can adjust as needed until you get the right plug color. If the plug looks white on the end youre too lean still. Lean is bad, its much better to be a little rich. Jetting can be a pain in the neck, but if you devote one whole day to it testing different jets and needle positions, youll be happy for the rest of the season

[Jingle #11]

thats about right but 155 seems a little lean. and doesnt race gas lean it out even more? but try around a 165.

[underpowered]

i have a 426, 11:1 HMF slip on, stockoil tank, K&N filter with no lid. I have a 165 main in it now, but need to go a little bigger. With an uni filter the 165 was perfect, pulled the plu today when i changed filters and had a nice tan color. I am gonna try a 175 an move the needle. The oil i run is Rottella. the oil they use in diesle trucks. It is what Scott Summers mechanic recomended to me, it is all the local shop uses to.

[Rider400ex26]

Send in some pics of ur wheeler man

[FoxRacing81]

I have the same setup (426 11:1, white brothers r4 slip on, no airbox lid, stock carb, stock oil tank) except I use UM Air Scoops and I have taken my headlights off (I can feel it running cooler now...all the air goes straight to my motor and oil cooler now) and I run Bel Ray Semi-Synthetic 20w50 oil...

For jetting with my white brothers filter (same as UNI), I run a 165 main jet and its perfect.

-Justin

[sprtrx300ex]

thanks guys,

Foxracing81, do you have a Tc924 cam?

I will post some pics when I get the motor in.

[Rider400ex26]

that wheeler looks sweet from the icon man must be totaly awesome in a large pic lol

[FoxRacing81]

Originally posted by sprtrx300ex
thanks guys,

Foxracing81, do you have a Tc924 cam?

I will post some pics when I get the motor in.

Nah, I have a hotcam stage 1...would like to get a better one...but it works fine for now.