My friend has a 03 night train he just replaced the cams oil pump lifters and pushrods.
Heat cycled the cams in after we primed the oil pump. Seems like he is getting a hesitation on throttle . It clears up at 3500 up. Running SE 258 cams. These are new cams but the same cams he was running before his cam shoe took out his cams and oil pump. Any input would be appreciated.

 

retune it

 

Since this is an '03 using SE parts, I am going to assume that it was a dealer flash due to the EFI being a closed loop system. A retune would not help and/or hurt anything IF the cams were exactly the same.

It is possible that the cams inside the box did not match the label on the outside of the box. Did the markings on the new cam match the old cam exactly?

 

+1 on re-tune, and definitely +1 on making sure the new cams were an exact match / not wrong ones in the box- if the cam events (intake / exhaust open and close) in the tune ecm code are different than the cam installed, you'll have issues like this. A good way to check is if you have a powervision or other tuner with real time display, see what the MAP reading is at idle - should be around 30 range. I'd also datalog a bit to see what is happening at the hesitation areas.
Make sure the pushrods were adjusted with proper preload on the lifters, usually .140 after finding zero lash. Good luck hope it is minor and it gets sorted.

 

it's 03 no closed loop no 02 sensors

 

What is the compression. Headwork? More details.

 

Forgot to mention the cams are the same as the old ones pulled out . Everything is the same just new. 10.2 compression 103 running a mikuni 45

 

I made sure the stamp on the cams matched the box

 

With a carbed bike it is usually a jetting issue. seems like when you hit the 3500 rpm mark it is getting to the point it is not fighting for gas.. maybe try a different set of jets and see if giving it more gas will help it down low a little.