1985 Yamaha FJ600 Problems - Motorcycle-Journal Forums

broush4125 · 09-06-2006, 01:40 PM

I have an FJ that will not run. The bike was stored for two years prior to me getting it. The bike will start with starter fluid but then dies. I have taken off the carbs and cleaned the bowls, jets, etc. All gaskets and diaphrams looked fine. I installed the carbs back on the bike. Now the bike will start but will only keep running with the choke fully on. If I turn the throttle the bike bogs down like it has too much fuel to burn and then ten seconds later or so the engine will rev. As soon as I start taking the choke off it dies. I have adjusted the throttle screw to the carbs to see if that would help and it doesn't. I am getting fuel from the tank to the carbs, ie petcock is working and fuel is traveling through the hose. Any suggestions would be much appreciated. I have replaced the oil, oil filter, air filter, fuel and put new spark plugs in with the proper gaps. I am also getting spark from each spark plug.

robs_seven · 09-06-2006, 09:52 PM

well im not to firmilar with motorcycles but i have a carberated car that had the same problem, its still not completely curred but i changed the jets and fuel pressure, which helped. I reduced my jets, by diong so the fuel pressure shot up, so i had to reduce the fuel pressure. after doing that i had to re adjust the air fuel mixture.

my guess is check fuel pressure at idle ,choke and throttle. then the air fuel mixture. just an idea

broush4125 · 09-07-2006, 08:48 AM

Robs_seven,
Thanks for the info. I will definitely try that. I am the third owner (that I know of) with this bike so a jet kit could have been put in it at one time. Thanks again.

alextnecc · 11-09-2006, 03:03 PM

I would definatelty start by checking out the pilot jet and the pilot circuit to start. See if you can get the bike to idle with the choke off first because the main jet and needle even if plugged would just starve the engine on the high side. Of course check for air leaks. But definately start with the pilot circuit.

buster · 08-22-2008, 08:51 AM

My mate had the same problem after it had been stored up, it was bits of dead spiders (or somesuch) blocking up the jets, he stripped the carbs right down cleaned them out thoroughly now it runs sweet.

tricker · 08-22-2008, 09:06 AM

buster · 08-22-2008, 09:18 AM

Oh yeah.... OOOOPS ... I thought was was kind of musty smelling in here....

Not a massive amount of activity in the Yam section is there?

09-06-2006, 01:40 PM	#1 (permalink)
broush4125 Newbie Joined: Sep 2006 Posts: 3	1985 Yamaha FJ600 Problems I have an FJ that will not run. The bike was stored for two years prior to me getting it. The bike will start with starter fluid but then dies. I have taken off the carbs and cleaned the bowls, jets, etc. All gaskets and diaphrams looked fine. I installed the carbs back on the bike. Now the bike will start but will only keep running with the choke fully on. If I turn the throttle the bike bogs down like it has too much fuel to burn and then ten seconds later or so the engine will rev. As soon as I start taking the choke off it dies. I have adjusted the throttle screw to the carbs to see if that would help and it doesn't. I am getting fuel from the tank to the carbs, ie petcock is working and fuel is traveling through the hose. Any suggestions would be much appreciated. I have replaced the oil, oil filter, air filter, fuel and put new spark plugs in with the proper gaps. I am also getting spark from each spark plug.

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09-06-2006, 09:52 PM	#2 (permalink)
robs_seven Newbie Joined: Sep 2006 Bike: 1986 virago 700 Location: NC (statesville) Posts: 2	well im not to firmilar with motorcycles but i have a carberated car that had the same problem, its still not completely curred but i changed the jets and fuel pressure, which helped. I reduced my jets, by diong so the fuel pressure shot up, so i had to reduce the fuel pressure. after doing that i had to re adjust the air fuel mixture. my guess is check fuel pressure at idle ,choke and throttle. then the air fuel mixture. just an idea

09-07-2006, 08:48 AM	#3 (permalink)
broush4125 Newbie Joined: Sep 2006 Posts: 3	Robs_seven, Thanks for the info. I will definitely try that. I am the third owner (that I know of) with this bike so a jet kit could have been put in it at one time. Thanks again.

11-09-2006, 03:03 PM	#4 (permalink)
alextnecc Newbie Joined: Nov 2006 Posts: 12	I would definatelty start by checking out the pilot jet and the pilot circuit to start. See if you can get the bike to idle with the choke off first because the main jet and needle even if plugged would just starve the engine on the high side. Of course check for air leaks. But definately start with the pilot circuit.

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