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General Category => Yamaha FJ1100 / FJ1200 Running Problems => Topic started by: xoomer on March 28, 2013, 08:29:57 PM

Title: Wont run.
Post by: xoomer on March 28, 2013, 08:29:57 PM
first off, I think my carbs are done, and I just need new ones.   :)

However If I pull the carbs, close the butterflys and set everything to bone stock (two and a half turns)  I will get it to start sometimes, and when it does I get popping from the exhaust, and out a couple of carbs.  and on top of that I have to fight it to come up off of Idle. (to rev the motor.)

I'm kind of a newb to motorcycles, I've worked on a few thumpers before but I just don't get this thing.  Any help or ideas would be appreciated.

I also have A/M pod Filters and a Sh*tcan  Muffler on this bike so this is not helping. 
Title: Re: Wont run.
Post by: FJmonkey on March 28, 2013, 08:33:45 PM
Some history will help us help you... Some carb issues are not tough to solve... What can you fill in? How long was it sitting?
Title: Re: Wont run.
Post by: Pat Conlon on March 28, 2013, 09:25:28 PM
Have you sync'ed the carbs?
Title: Re: Wont run.
Post by: craigo on March 28, 2013, 09:27:03 PM
If money is no object, send them to Randy @ RMP. He will set you up with an as new set ready to install. If money is, check out the files section. Andy posted some excellent tutorials on carbs there.

CraigO
Title: Re: Wont run.
Post by: xoomer on March 28, 2013, 11:47:12 PM
I really don't know much about the bike, I've tried rebuilding the carbs, (I've rebuilt weber carbs many times)  and I just can't dial it in.  When I bought it, it was running.  Unfortunatly I didn't look at the tank and everything got clogged up.   I've pulled it apart with the files available and put it back together.   but I still cant get it to run.
Title: Re: Wont run.
Post by: moonrunnah on March 29, 2013, 04:13:21 AM
Quote from: xoomer on March 28, 2013, 08:29:57 PM

I will get it to start sometimes, and when it does I get popping from the exhaust, and out a couple of carbs.  and on top of that I have to fight it to come up off of Idle. (to rev the motor.)


explain popping out of the carbs because that sounds like an old four wheeler i had and i bent the intake valves it cause a popping or explosions out of the carb (littleraly had flames popping out of the carb)
Title: Re: Wont run.
Post by: yamaha fj rider on March 29, 2013, 05:46:19 AM
If this has not run for awhile could be blocked pilot circuits. With junk in thank even just cleaned carbs can be blocked. Clean the fuel tank then carbs and flush lines, fresh gas, probably fix the problem. Hope this helps.

Kurt   
Title: Re: Wont run.
Post by: SlowOldGuy on March 29, 2013, 09:25:00 AM
"Popping" in the exhaust and "spitting" back through the carbs (NOT backfiring!) is typically a clogged idle jet/circuit.

This should also be the reason you can't get it up off of idle speed.  The carbs also need to be synced, like Pat said.

DavidR.
Title: Re: Wont run.
Post by: pdxfj on March 29, 2013, 02:04:02 PM
Go to your local Harbor Freight and grab their big ultra sonic cleaner.  See if you can find someone who sells Amway and get some of their LOC.

Fill the ultrasonic cleaner with water and LOC.  Run the heating cycle until it's really hot.  Heating water on the stove can quicken up this process.  Don't bring it to boiling.

Disassemble one carb at a time.  Remove everything.  Put the carb, jets, emulsion tube and float bowl in the UC cleaner and run a cleaning cycle.  Flip the carb over and and run another cycle.

Rinse carb off in hot water and repeat the process on the other carbs.  If you feel the carbs need more cleaning, just run more cycles. Be sure to keep the heater on so the water says really hot.

Be sure to change the solution after each carb.  I've done this on several sets of motorcycle carbs, clutch and brake masters and it really works well.  Everything comes out looking new.
Title: Re: Wont run.
Post by: ribbert on March 29, 2013, 07:42:07 PM
Just to make sure the basics are covered, is the choke connected and working? 
What you describe is not unlike trying to start a cold motor with no choke.
Noel
Title: Re: Wont run.
Post by: xoomer on March 30, 2013, 09:06:38 PM
Its really weird, as sometimes it will start just fine and idle up with no popping and will rev just fine.  then other times it basicly sticks its middle finger at me and wont start.  I'm really thinking I need to buy the new carbs from RPM but, I havn't had the bike running long enough to know how good the motor is.  (unless someone knows where I can find a motor.)


Title: Re: Wont run.
Post by: craigo on March 31, 2013, 12:11:30 AM
Run a compression test. Easy to do and the part is cheap (relatively) Just take the plugs out and screw the end of the tester into each hole. Crank the motor and write down the number. Should be in the 140's across the board. I could be mistaken on that number and I'm sure someone more in the know will chime in.

CraigO
Title: Re: Wont run.
Post by: ribbert on March 31, 2013, 03:55:57 AM
Quote from: craigo on March 31, 2013, 12:11:30 AM
Run a compression test. Easy to do and the part is cheap (relatively) Just take the plugs out and screw the end of the tester into each hole. Crank the motor and write down the number. Should be in the 140's across the board. I could be mistaken on that number and I'm sure someone more in the know will chime in.

CraigO

.....and the motor should be at operating temp with the throttle held wide open while cranking.
Title: Re: Wont run.
Post by: andyb on March 31, 2013, 08:21:37 AM
If you're an admitted novice to working on bikes, why do you diagnose the carbs as "done"?  Takes a healthy wallet to support that quality of troubleshooting.


What do the plugs say?
What does a compression check show?
Is there a common thread with weather conditions in which it runs well?
How old is the gasoline?
How much history of the bike do you have?
Why do you set the mixture screws at stock when there are modifications?

It's just an engine.  Fuel, spark, air.
Title: Re: Wont run.
Post by: markmartin on March 31, 2013, 08:36:08 AM
Quote from: Pat Conlon on March 28, 2013, 09:25:28 PM
Have you sync'ed the carbs?


Or even bench sync'd it after the rebuild?

xoomer, stick with it.  From what I've seen on this forum, it's pretty hard to actually kill one of these bikes. It sounds like your willing to dive in and do things.  Good.  Answer the questions that are asked of you when you are seeking help.  There are folks on this forum that can and will walk you through every nut, bolt and bit on your bike until you get it running.  

Think about how good it's going to feel to get that baby running again.

Mark
Title: Re: Wont run.
Post by: xoomer on March 31, 2013, 03:44:07 PM
I've torn it apart, and bench synced my carbs.  I can get it to start sometimes but never much more, last weekend I was able to get her out for a spin down the driveway but limped back because she didn't have any power. 

So far,

Cleaned the tank and sealed it. 
newer (functioning Petcock)
new line.
Carbs off Multiple times Last time soaked in cleaner and Re-assembled.
baffles appeared to be acceptable

:/  I went to crank on her today and she weakly started and then said never more.   :?
Title: Re: Wont run.
Post by: Pat Conlon on March 31, 2013, 04:13:01 PM
Does it smell like it's flooding? Are the plugs wet?

Stay with it Zach.
Title: Re: Wont run.
Post by: xoomer on March 31, 2013, 08:30:35 PM
well, after playing with it today, I'd almost say its not getting enough fuel.  but then the carbs started dribling out of the over flow.  :/

I'm gonna put it up on craigslist I think and get the first $650 I can get out of her. :/  either that or get it out of my driveway till I can find a set of carbs that I can "Try"



Title: Re: Wont run.
Post by: racerrad8 on March 31, 2013, 08:35:41 PM
As already mentioned, you can send me the carbs. I go through carbs, ultrasonic clean them and reassemble for $125.00 plus the $22.00 S/S screw & o-ring kit. If you need other parts when I get them torn down I will be able to explain all of your options.

If interested, email me; randy@rpmraingca.com

I can also put them on my bike to make sure they run.

Randy - RPM
Title: Re: Wont run.
Post by: jscgdunn on April 01, 2013, 02:49:47 PM
Carburetors: that's what life is about.  They really are a rite of passage for vintage MC ownership.  My first experience with a Yamaha 400 involved cleaning at least three times.  It would not start either and would only run on one cylinder when cold.  The ultimate fix turned out to to require a bit of heat from a heat gun on the float bowls to get the carmalized gas out of the passage in the bowl.  So clean means very clean for all the passages.

That is a great offer from Randy, but I am sure you want some more frustration :ireful:.

A few things that I have learned:
1) When cold, the choke has to be completely engaged or it will not get enough fuel to fire.  If you have the right side panel off push the choke rod check to see it is all the way engaged. Push the rod to the left till it stops.  Even 1/8 inch can make a difference.
2)  You should not need to turn the throttle; it should start on choke, but sometimes a little turn does help.
3) If you had the tank off to R&R the carbs, there could be now sediment that was disturbed plugging the fuel filter (if you have one.)

As it ran before, with the pods, it should run again, but we have seen them not start until the airbox cover is put on.






Title: Re: Wont run.
Post by: pdxfj on April 02, 2013, 02:29:22 PM
Quote from: xoomer on March 31, 2013, 08:30:35 PM
well, after playing with it today, I'd almost say its not getting enough fuel.  but then the carbs started dribling out of the over flow.  :/

I'm gonna put it up on craigslist I think and get the first $650 I can get out of her. :/  either that or get it out of my driveway till I can find a set of carbs that I can "Try"

So your sig says you're an ASE Certified mechanic and you're giving up this easy?  This isn't a modern day car with fuel injection and an OBD-II system that will basically tell you what's wrong.  It's an old school and rather simplistic machine. 

Fuel is dripping out of the small vent tubes?  You've either got a bad o-ring around one of the seats for the fuel needle, or some crud in the seat.  Take a Q-Tip with some carb cleaner on it and clean the seat.  You'd be surprised by what comes out.

Not getting enough fuel?  Have you tried opening up the idle mixture screws a bit more?  2 to 2 1/2 turns is a starting point.  Are you sure the choke passages are clear?

We all feel your pain because we all have been there at one time or another.  As another member said, FJ carbs are a right of passage.  Everyone deals with carb issues.  The light at the end of the tunnel is once they are sorted out, you don't have to do much with them.  Keep them clean and replace worn bits when needed and they will serve you well.

I had carb problems with my FJ when I bought it over 10 years ago.  After fully cleaning them, in all that time the only thing I've done to them is a carb sync every now and then.  Even after sitting through the long and wet PNW seasons I roll it out to the driveway, fully open the choke, and start cranking.. it takes a few minutes to fill the float bowls but after that she coughs to life and settles in on a nice idle.  I have pulled them a couple of times and checked the float bowls and not once has there been any sign of crud...

My carbs need e-tubes and slide needles.  I can't even ride 165 miles from Portland to Puget Sound on a tank of gas...but the bike fires up and runs great.

If you box up your carbs and send them to Randy, they will come back looking like new and as he said he will put them on his bike and test run them.

Hell for $650 I'd drive to Seattle and buy it.. bring it back to Portland, clean the carbs and sell it for at least double if not triple the purchase price..
Title: Re: Wont run.
Post by: xoomer on April 02, 2013, 11:18:39 PM
I don't have the patience to mess with it.   :(  I think I'll take your offer of 650$  or I'm going to have to send these carbs to randy. 


Randy, I've tried emailing you but the email came back with fatal errors.  I'll send you a pm or try again.  I'll probably send them to you and say.... make them good.  but first I'm going to do a compression test across the cylinders.   :) make sure the motor isn't sad.


:)
Title: Re: Wont run.
Post by: racerrad8 on April 02, 2013, 11:20:31 PM
randy@rpmracingca.com

Randy - RPM
Title: Re: Wont run.
Post by: fj1289 on April 03, 2013, 12:36:02 AM
Quote from: xoomer on April 02, 2013, 11:18:39 PM
I don't have the patience to mess with it.   :(  I think I'll take your offer of 650$  or I'm going to have to send these carbs to randy

Send them to Randy!  It will be money extremely well spent in trade off for patience. 
Also make sure the battery is in good shape and fully charged.  Twice I've had a failing battery give me ignition problems where it would idle but not take any throttle.

Good luck!

Chris
Title: Re: Wont run.
Post by: pdxfj on April 05, 2013, 05:26:12 PM
I'll toss my hat in with the others on sending your carbs down to Randy.

If you decide not to and really want to get rid of the FJ shoot me a PM and we will work something out.
Title: Re: Wont run.
Post by: RichBaker on April 12, 2013, 03:58:10 AM
Quote from: xoomer on March 31, 2013, 03:44:07 PM
I've torn it apart, and bench synced my carbs.  I can get it to start sometimes but never much more, last weekend I was able to get her out for a spin down the driveway but limped back because she didn't have any power. 

So far,

Cleaned the tank and sealed it. 
newer (functioning Petcock)
new line.
Carbs off Multiple times Last time soaked in cleaner and Re-assembled.
baffles appeared to be acceptable

:/  I went to crank on her today and she weakly started and then said never more.   :?


You need to do more than just soak the carbs in cleaner. Get aggressive, blow compressed air thru EVERY passage in the body of th carb, in the float bowl and make sure all passages are clear. Use a straw and cigarette smoke (or buy a can of smoke, google it) to visually SEE that they are clear....
Make sure ALL the brass, including the emulsion tube, is clear. Hold it up to a bright light and look thru the holes...
Title: Re: Wont run.
Post by: crzyjarmans on April 14, 2013, 07:46:56 AM
And if your really bent on selling her?, Shoot me a PM, I've got an 87' this 86' will give me lots of spare parts, plus a motor I can rebuild, But If I was you?  I wouldn't give up so easy