Ok so I have a 74cid shovel bored .30 s&s 450s cam super e carb. I'm running a 66 main jet and a 28 intermediate. Straight pipes and a moon eyes air cleaner. The bike starts and runs good until I go wide open throttle then it just cuts out and sputters until high rpm I have changed both jets according to s&s website and can't get rid of the sputtering. It is points ign. And have checked the advance weights and they are in good condition any ideas?

 

The way you have it set-up...Drag pipes and **** poor air cleaner...it is Working accordingly...Take it to the Drag-Strip.

Revisit the S&S tutorial and pay attention to the air cleaner/Exhaust Discussion.

Or Not.

 

I agree it's not my bike I'm working on it for another guy I'm trying to talk him into putting a CV on it and a different air cleaner but want to try to get it as good as I can because he doesn't want to change stuff

 

we in the shop keep original stuff like a real S&S air filter and when this happens we have the guy jet it the way i see it and use the correct air filter

then he can screw it as much as he wants to knowing the correct way works and something that is cool well its cool does not work but sometimes is wayyyyy cool

 

I thought about taking the cv/big sucker off of my personal bike to show him that there are better ways, does anyone think that it is possible to get it to run decent the way it is? I guess what I'm trying to say is that he's not trying to get peak performance just wants it run decent

 

It's just my opinion that a cv or makuni is way better than a s&s

 

So is it the just not getting enough air because of the tiny filter?

 

if you are talking about sputtering when you twist the throttle, you may need to look at the accelerator pump adjustment.
I don't see any reason to replace the S&S carb. Thinking about pipes, and air cleaners, yes. Replacing the carb is not needed.

 

Air filter is bogus but try a .295 with a .70 main with the plug gap opened about .005 more and try it. Some bikes like a .031 intermediate with straights.

 

I tried every different combination of jets that we have at the shop from a 25 & 60 all the wa to like 31 & 74 with no luck. And finally just removed the air cleaner and guess what! ? She rips! So I told the owner that I was done messing with it until he put a real air cleaner on it