hey guys im new to the forum, that being said i need some help. i know there is a vaccum line that goes from the petcock to the number 1 carb. do i have to have this line hooked up for it to run? my motor is flooding out really bad is this the cause? if i plug this line will it solve my problem? and can anyone tell me what this line actually does? i know where it goes but what does it really do

 

Hello,
The vacuum line that goes from your carb to the petcock does one thing. It opens the petcock with vacuum, so fuel only flows while the engine is running.Yes this line should be connected for the bike to run. This is petcock is not likely the problem, unless the diaphram in it has ruptured. If you turn the valve on or on reserve and fuel flows without the vacuum line connected and a source of vacuum, then the petcock is likely faulty. Normally hooking a vacuum pump to the petcock vacuum port is required to make fuel flow for test purposed. Flooding can be cause from carbs malfunctioning, poor spark, or poor compression (valve adjustment etc).

 

Likely a stuck float needle. Strip the carbs, clean and adjust the float needle and heights.

 

The F3 doesn't use a vacume shut-off to the petcock.
It is purely mechanical based on the 3 position valve.
Up is reserve, down is main and midway between is off.

Sounds more like Corrupt's take is correct.
Either stuck float or clogged jet.
Pull the carbs and give them a good cleaning.

There is no adjustment to the floats, by the way. They are either right or wrong.
However the needle seats or the needles themselves may be damaged
and not sealing properly. Replacement is the correct solution, in that case.

Ern

 

thanks for the help guys, im leaning twords a timing issue being my problem and i know the ignition timing is fixed on these other then cam timing, butt what if someone took the coils out and put the wires in the wrong place. not the wires from coils to plugs but the actual wire harness wires, what would happen in that case? would it make the coils fire in the wrong sequence.... ergo incorrect timing?

 

My guess would be that it would not fire up at all

 

alot of back firing. didnt start up. i have since tore my carbs down to clean. but anyways next question anyone know what thread the temp sending unit is on these? im gonna put an aftermarket temp gauge cluster in and i want to use an electric one and im not sure if the stock sending unit will work with the aftermarket guage