I got the ZEX kit with 55hp shot. I know that this question is very common in this forum but I want to clear my mind; Can I run a 65 hp shot with my stock fuel system, it is safe?

 

you can,... but its not recommended.

Your pump and injectors might not hold up.

You can probably get away with a 75 shot just by upgrading your fuel pump.

 

The 65 shot is pushing the edge, but is doable. I suggest you start with a 55 and work your way up. For above 65, you will need a larger, higher volume fuel pump. At the 65 shot stage, it wouldn't hurt.

 

When I had my Zex in, I was running a 65 shot on the streets and a 75 on the track. I upgraded my fuel pump, and injectors to be safe. However, Long runs a 65 shot in his tib, and he still has all the stock fuel parts. Not sure how often he sprays though, but he said his Tib is fine. Just better to be safe than sorry and upgrade your fuel setup. wink.gif

 

to be safe get an AF meter and pump, the pump is cheapish at $110 or so and takes 1 hr to install, the AF meter is $29 bucks. 65 is at the very limit of the stock system, you might be ok but one clogged injector and suddenly your lean.