I noticed that the carbed bikes have a small coolant line that feeds hot water through the carbs. My guess is this is to help prevent ice in cold weather. Since it never gets blow 40 degrees here (midnight in the "dead of winter"), I don't have to worry about ice. Instead, I'm more concerned with keeping the fueling system as cool as possible in the heat.

Anyone have any reason NOT to remove it? Unless someone can think of a very good reason to have it, I'm going to bypass the line around the carbs to keep them cool.

Chris

 

did it on my old 240sx for the same reason, cant see why itd cause any harm

 

Does the F4i have a "hot water" loop to the Throttle Bodies? I noticed the F4 and F4i thermostat housings have the same "out" port that would go to the TB/Carb, but the F4i pump does not have the "in" port from the TB/Carbs like the F4 pump does.

 

never mind.... just found the answer on ebay. F4i has a different water neck that mounts on the block. The F4i version has the "in" port that would otherwise be on the water pump. From what I can tell looking at pictures of complete engines for sale on ebay, the F4i just loops this coolant line (much like I will be doing bypassing the Carbs).