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General Category => FJ Project Writeups => Topic started by: mk160fc on June 06, 2015, 02:27:05 PM

Title: Project FJ600
Post by: mk160fc on June 06, 2015, 02:27:05 PM
I have this 84 FJ600. Been working on it for about 6 months now. Finally got to the day to start her up and she ran for about 5 seconds. Tried to start it up again but will just sit and try to turn over. Every now and then she'll run for a few seconds. Any suggestions? Thanks!
Title: Re: Project FJ600
Post by: FJmonkey on June 06, 2015, 02:45:30 PM
Have the carbs been thoroughly cleaned? Sounds like really gummed up dirty carbs.
Title: Re: Project FJ600
Post by: mk160fc on June 06, 2015, 02:59:14 PM
They have . I even made sure everything moved after i installed them. I adjusted the idle knob and i can  almost get a consistent start but it loses rpm and dies
Title: Re: Project FJ600
Post by: FJmonkey on June 06, 2015, 03:22:08 PM
Follow the basics, air, fuel. spark. it starts so you are getting spark. Also seems like you are getting air. So make sure you are getting fuel. After it dies, check to see if the float bowls are full. not just some fuel but full. If the bowls are not full then test the petcock for fuel flow.
Title: Re: Project FJ600
Post by: FJmonkey on June 06, 2015, 03:31:21 PM
Just for giggles, who cleaned the carbs? And did the cleaning involve an ultrasonic cleaner?
Title: Re: Project FJ600
Post by: mk160fc on June 06, 2015, 03:33:31 PM
I did and no. Lol im just gunna take them off and recheck everything  :dash2:
Title: Re: Project FJ600
Post by: FJmonkey on June 06, 2015, 04:08:31 PM
Make sure the idle jets are clean. And that you can spray carb cleaner through the idle passages.
Title: Re: Project FJ600
Post by: Steve_in_Florida on June 07, 2015, 07:28:25 AM
MK,
When you cleaned the carbs, did you REMOVE the main nozzle under the needle? (Part #13 in this diagram):

     http://www.partzilla.com/parts/search/Yamaha/Motorcycle/1984/FJ600L/CARBURETOR/parts.html (http://www.partzilla.com/parts/search/Yamaha/Motorcycle/1984/FJ600L/CARBURETOR/parts.html)

All the little holes need to be open. No gunk or residue. None. Not even a LITTLE!

Really.

Steve
With carbs, there's cleaning, then there's Cleaning, then CLEANING!
Title: Re: Project FJ600
Post by: mk160fc on June 07, 2015, 10:07:52 AM
I didn't know how to remove them. I tried a punch but it looked like I was warping it so I stopped before i did terrible damage.  I looked down in there with a light and it looked good. I took them apart yesterday and cleaned them out again. Ill see what happens tomorrow.
Title: Re: Project FJ600
Post by: ct7088 on June 07, 2015, 02:12:53 PM
Use an old jet with no washer(the washer under the jet is what holds the nozzle in place). Press against something solid, they come out relatively easy. Dont twist the nozzle in a circle because there is a small brass pin that sets in a slot in the nozzle. Once the nozzle and hole are clean it can be pushed in and out with your fingers. I soaked my carbs in Berryman's Chem Dip with no ill effects. The part number for the 600 nozzle isn't the same as the 1100 but the construction of the carb looks the same.
Title: Re: Project FJ600
Post by: mk160fc on June 07, 2015, 09:44:03 PM
Quote from: ct7088 on June 07, 2015, 02:12:53 PM
Use an old jet with no washer(the washer under the jet is what holds the nozzle in place). Press against something solid, they come out relatively easy. Dont twist the nozzle in a circle because there is a small brass pin that sets in a slot in the nozzle. Once the nozzle and hole are clean it can be pushed in and out with your fingers. I soaked my carbs in Berryman's Chem Dip with no ill effects. The part number for the 600 nozzle isn't the same as the 1100 but the construction of the carb looks the same.

Do I push from the bowl side or the float side?
Title: Re: Project FJ600
Post by: ct7088 on June 08, 2015, 06:26:35 AM
float side
Title: Re: Project FJ600
Post by: mk160fc on June 08, 2015, 08:11:22 AM
After doing a bit of research, I'm convinced that my floats need to be adjusted. From the symptoms I think I'm  running way rich. I'll lower the bowl levels and see if she'll actually stay running. I'll update tonight.  Thanks for all the help.
Title: Re: Project FJ600
Post by: mk160fc on June 08, 2015, 03:53:18 PM
I started the bike today. I got it to idle. Cylinder 4 was smoking from where the exhaust meets the cylinder. #2 carb had fuel leaking from it and the exhaust pipe was much cooler than the rest. I'm thinking #2 is running rich and #4 might be running lean. What do the experts think? Thanks for all y'alls help. I couldn't have gotten this far without it.  :good2:
Title: Re: Project FJ600
Post by: JPaganel on June 08, 2015, 04:27:21 PM
#2 is running rich, but leaking fuel indicates you got your float set too high.
Title: Re: Project FJ600
Post by: mk160fc on June 08, 2015, 04:42:45 PM
Quote from: JPaganel on June 08, 2015, 04:27:21 PM
#2 is running rich, but leaking fuel indicates you got your float set too high.

What about #4?
Title: Re: Project FJ600
Post by: JPaganel on June 08, 2015, 05:14:18 PM
Quote from: mk160fc on June 08, 2015, 04:42:45 PM
What about #4?
Hard to say.

Could be some oil dripped there. You do know about the valve cover and donut relationship, right?

Could be burning some oil, or running rich,  and the exhaust gasket is horked.

Title: Re: Project FJ600
Post by: fj1289 on June 08, 2015, 05:15:55 PM
Id agree it sounds like #2 is rich - but only because it has flooded.   Probably not caused by float level --  probably caused by 1. Trash keeping the seat from sealing, 2. Float needle seat is worn, 3. Or similar to FJ1100/1200 carbs, the o ring around the needle seat body is leaking around the float needle seat assembly, or maybe 4. Stuck float. 

#4 is simply an exhaust leak or some residual oil on the pipe.

Keep it simple guys.  Float level, unless you've really jacked it up bad, isn't going to be causing a no idle issue.  It can be very helpful for the FINAL FINE TUNING of the transition from idle to off idle.   

As someone has already said - idle issues are almost always a carb cleaning issue dealing with the pilot (aka idle) circuit.   The ones that aren't are the o ring around the float needle seat assembly. 

This issue comes up at least 4 times a year.  Each time the poster swears the carbs are clean and tries everything (float levels, etc) except a thorough cleaning of the pilot circuit with no result.  They break down and eventually really get the pilot circuit clean (either themselves or by sending them out) and are amazed by how well it runs then.

Hang in there - dirty carbs are just a rich of passage to breathing life back into an old beast -- and well worth the troubles!  Good luck and keep us posted   :drinks:

Title: Re: Project FJ600
Post by: mk160fc on June 08, 2015, 07:07:28 PM
Well I no longer have the idle issue after I took them apart and cleaned them again saturday. Today I could get it to idle everytime. After about a minute of idling I'd get smoke from number 4 and the idle would fluctuate about 500rpm (I'm assuming because #2 was flooding). I did have a problem with #2 float sticking a bit before I put them back on.  I'll have to take them off again and see what I can do about that. Thanks for all the help! I'll post all the pics I have once I can get her on the road!

One more question, Whats the difference in the models of the 600s with the dual and single exhaust? Mine has the single.
Title: Re: Project FJ600
Post by: FJmonkey on June 08, 2015, 07:16:28 PM
Could be an after market pipe.
Title: Re: Project FJ600
Post by: mk160fc on June 18, 2015, 03:59:50 PM
OK! so you guys have been super helpful and I appreciate it so much. :good2: I have fixed the flooding carb. So I would like to ask for help on a few monre things.

d1)Turns out the smoke isn't from the exhaust. it doesnt start until the engine has warmed up a bit. and it starts really coming out. it appears to come from the whole engine.
2)The bike will idle around 1200 rpm until warm and then idle just keeps increasing. Happens about the same time as the smoke.
3)My oil light doest go off and a good bit of smoke from the tail pipe

Hypothesis:
vacuum leak and/or oil pump broke?

Thanks for any help guys.
Title: Re: Project FJ600
Post by: PaulG on June 18, 2015, 10:16:28 PM
Possibly plugged crankcase ventilation?