NEW CUB BUILD

[badassbanshee479]

check and make sure the deck of the cylinder is true, when the platers sand blast the cylinders they have been putting low spots in the deck causing the cylinder to suck water, also make sure your head is true. there is alot of things to check when putting one of these motors together, you cant just slap it together and hope it works. What is your elevation? what size carbs are you running? my 4 mill on gas with 39 pwks liked 165 mains and 60 pilots. If your fibers have no grooves they are smoked! get with jeff from FAST and get one of his clutch kits, I have one and it has been going strong for 2 years, ad most of that was on a 4 mill cub with no lock up.

[Animalman294]

Yeah, Jeff will hook you up right.................

[badshee]

my elevation is 2000 ft above sea, and im runnin 34 pjs, wiht cpis, and i just put some diff jets in it, i have 42 pilots and like 145 mains, and my screw is 2 turns out and my clip is on the 4 spot..... ill fire it up tommorrow and see were im at then....

[Animalman294]

I would try a 45 pilot, and a 160 main..................

[Crazy05]

If you have coolant in the cylinders, fix that first.

Do a compression test. Borrow or buy a tester.

Thouroly clean all the jets in the carb,

Tune the idle 1rst. After adjusting the air screw if your more than 2 turns out put a smaller pilot less than 1 bigger pilot.

Ride it easy and see how the throttle response is from 1/4 to 3/4. Move the clip one adjustment up or dow and ride it easy. If it feels better move it one more. but if it feels worse, go the other way. get that as good as you can then do a brief WFO run and add bigger jets till it runs bad then back off 1 or 2 steps. Now you get to play with the needles. I havent got to that yet as my bike ran good with the needle thats in it. But from what Ive read, you want to make one change at a time and ride it. Its a pain and takes lots of patience. Needles have 3 adjustments. Length, diameter and taper. A carb with the proper length needle will ride on the middle (3rd) clip position or 4th position from the top. So Keihin says. diameter detemines a/f ratio in the mid range. 1/4 to 3/4 throttle. Thinner is richer, thicker is leaner. Taper determines the same but different. If when you lean at 1/4 but rich at 3/4 or visaversa you need to change the taper. Start with a CEL needle and work from there. That seems to be a common choice with your motor. Be patient and take the time to get it tuned right and you will be glad you did.

[Animalman294]

Yes you should always make one change at a time so that you will know which change made the difference good or bad....................

[87sheerips]

If you have coolant in the cylinders, fix that first.

Do a compression test. Borrow or buy a tester.

Thouroly clean all the jets in the carb,

Tune the idle 1rst. After adjusting the air screw if your more than 2 turns out put a smaller pilot less than 1 bigger pilot.

Ride it easy and see how the throttle response is from 1/4 to 3/4. Move the clip one adjustment up or dow and ride it easy. If it feels better move it one more. but if it feels worse, go the other way. get that as good as you can then do a brief WFO run and add bigger jets till it runs bad then back off 1 or 2 steps. Now you get to play with the needles. I havent got to that yet as my bike ran good with the needle thats in it. But from what Ive read, you want to make one change at a time and ride it. Its a pain and takes lots of patience. Needles have 3 adjustments. Length, diameter and taper. A carb with the proper length needle will ride on the middle (3rd) clip position or 4th position from the top. So Keihin says. diameter detemines a/f ratio in the mid range. 1/4 to 3/4 throttle. Thinner is richer, thicker is leaner. Taper determines the same but different. If when you lean at 1/4 but rich at 3/4 or visaversa you need to change the taper. Start with a CEL needle and work from there. That seems to be a common choice with your motor. Be patient and take the time to get it tuned right and you will be glad you did.

 

 

WTF pipes are you runnin?? They look crazy sweet!!!!