FJ Stopped Starting

[cevans21]

Hello,

My name is Codie, I recently purchased an 85 FJ 1100 for my siblings and myself when I am home. I am currently on leave for a couple weeks from the military and wanted to take some people riding HOWEVER my FJ stopped firing up. My idiot friend bump started it and dropped it so I had to replace the clutch cover and rear brake but now that I have done that I still cant figure out why it wont fire up.

It cranks and cranks when I have the battery starter on it it cranks more powerfully but still wont turn over. This is my first Street bike thats not a sportster so I am hoping that Someone can help me out so I can get on the road before I go back. Plus I want to start learning more about the FJ as they are really cool bikes.

Thanks
Codie

[FJmonkey]

Welcome Codie. Fuel, air and spark. Make sure you have fuel. The bottom of each carb bowl has a drain screw and spigot. Check each carb and see if 2 to 3 oz drain out of each.

Lesson 1 on '84 to '87 FJs. They are gravity fed carbs and use vacuum to open the petcock and fill the carbs with fuel. If your carbs are empty then the petcock is the next thing to check. Be prepared to suck your petcock...

Fuel line routing is also critical, let us know when you get to that point.

[cevans21]

Thank you! I will get on this tomorrow and keep you posted..

[movenon]

Welcome!  Simple things first. Run/Stop switch in RUN. Check the fuses.

It is trying to fire ? Might give it a shot of starting fluid.  If it tries to fire then at least you know the problem is probably in the fuel system.  As FJmonkey noted,  start at the petcock (it is vacuum operated) and check the hose routing.  The hose routing is critical.

The 84/85 FJ fires up by first using the exiting fuel that is in the carb bowls.  Think of it as a "prime".
With the engine started it now creates a vacuum signal for the petcock to open up and to continue fuel flow. (safety feature, when the bike is turned off then no fuel flow)

If your carb bowls are empty in the first place then it can't fire to create the vacuum signal for more fuel to be sent to the carbs.  Putting a manual vacuum (suck test) on the hose attached to the petcock should allow fuel to gravity feed down into the carbs if the hose line is routed correctly. 

Also worth mentioning there should be NO fuel filter in the line on your bike.

I am just repeating what FJmonkey has said.  He is an expert on that fuel system.  In later years Yamaha changed the fuel feed system at least 2 times.

You mentioned that your friend dropped the bike while trying to bump start it.  Was it running when you bought it ? 
George

[cevans21]

Thanks! Yes it was running for 2 days solid I rode all day and then had to leave again for training. However I am back now, about to go look at the bike now. I will look at everything you guys mentioned and hopefully report back that I am up and running tonight. Thanks!!