Help Fuel Problem

eldan820

Registered
I have a problem on my 99 busa!! I just cant figure out what is wrong with my fuel system. My bike runs perfect for like 5 miles then once its warmed up it starts to act up. Looses tons of power, backfires, and even the way it sounds is different. I did a full fuel system clean up and its still bad. The weird thing is that once its warmed up the fuel on the fuel pump seems like is boiling!! Anybody had the same problem on their bike?? I need help on suggestions on what to check or replace. Fuel pump? Regulator?
 
My 99 had a problem where after a bit it would die. I remember it explained to me that small amounts of the metal with American gas will sluff off and fill the fuel injector screens with a copper film particles effectively blocking them. The solution to the external fuel pump bikes was to just remove all fuel system filters in injectors, etc. etc. except the strainer screen in tank. (all you really need) I myself and many others did this and it completely solved problems.. never happened again.
 
Is the bike new to you ? Early models have a vapor lock issue because of what you describe. I have heard of people wrapping there pumps in a beer coozy to relocating the pump to a cooler area. Best of luck
 
It could also be valve lash set too tight. When valves get hot they lengthen, thus why there is valve clearance. I know that's the case when they get really hot, but just warming the bike up could do the same.
 
I was going to say filter, but if it's only doing it hot, that probably isn't the case.
 
I had those issues as well. I changed the stock fuel pump to a kit from MCXpress. The same as they use in their turbo kits and now it runs perfectly.
 
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