Running then not repeat......

[DreadRock]

   Well im new to FJs but not bikes and at a loss at what my new to me FJ is doing . The PO told me the bike would run fine then about 10 miles out wants to bog then die. After a few min it would start up and run for a short time and so on .... Well after getting it home Sat did some looking and saw that a pinched fuel line might be the problem . Well it was and i thought i fixed it as i went on 2 25 mile runs and no problems at all. Then today i jump out on the bike and after 10 miles just seemed to bog but as long as you gave it gas would run but poorly and if you come to a stop dies. I also saw the Tac drop to 0 rpms but bike was again boging but running . After i let it set it started right up like notheing wrong and then it repeated but only after 2 miles ( on my favorite road ) and let it set but took seat off and wiggled the wiring around battery box and started right up and ran the 8 miles home with no problems. Thought maybe coils but dont seem to act like it . Read some place here about the side stand haveing problems or think it could be something grounding out or rubbing on a bad spot on the wiring some place ? Any help would be great Thanks !

[Dan Filetti]

Sonds like fuel starvation to me.  May be the fuel cap not letting in air to compensate for the vacuum formed when the gas is drawn from the tank.  This problem get's worse/ more noticeable with less fuel in the tank. Next time this start to happen, notice 1. how much fuel you have, and 2. whether it is stops if you open the fuel cap.  also, after a ride or immediately after the bike stalls, as you open the cap, see if you hear a woosh as the air equalizes, if so, then this is almost certainly your culprit.   Search for 'flapectomy' as a fix for this.

If this is not it, it may be your float levels are not allowing enough fuel in, although I can't explain why the problem went away...

Good Luck,

Dan

[DreadRock]

cool will looking into that as when this happend was indeed need of fuel but still did after putting in fuel . But would that also cause the Tac to drop to 0 rpms and when you give some gas can hear motor rev up but tac doesnt  move then after it startes up tac works fine ? Thanks for the help

[SlowOldGuy]

If the tach dropped to 0 and it feels like it's running on 2 cylinders, then you're losing the 2-3 coil.  Check/clean the coil connectors under the front of the tank (remove tank first).

The rest of the symptom sounds like pinched fuel line or plugged tank vent.  Could be some of all 3.

DavidR.

[DreadRock]

Did pull off the tank and front nose to see if a wire was grounding out and found the brown wire from the horn,turnsignal,hi/low was showing copper and grounding on the frame . So took care of that and didnt see any other. So back on nose,tank and back out on the road and seemed to be running great . Did some back roads then jumped on highway and keep it at 75 for 15 mile still good . Went thur town and stoped at gas station as was thinking i got it till i tried to start it and seemed to drop 2 cyls so i limped it home and back up on the table . let it sit for a few to take the tank off and seemed to run better but chopy. So befor i get into it any more going to wait for the shop manuel i ordered. Has dyna 2000 coil and box not sure how old and if one went bad then other could be close so will pick up 2 new ones. thanks for the help guys
Hate not having a manual  but on the breather there is the fuel line and one tube from carb/boot going to the petcock and one tube near the front that 3 inchs long  is this right ?  Again thanks for the help !

[SlowOldGuy]

For about the last year or so, I've had a chronic problem of the 2-3 coil dropping out on my '85.  Coincidently, it also has a Dyna 2000 ignition (and coils, and wires).  A few weeks ago, I swapped out the ignition box for a spare unit that I had. 

It would run for hours without a problem, then I'd roll off the throttle to slow down.  When I'd pick the throttle back up, the tach would drop to 0 and I'd be running on 2 cylinders.  Couldn't get it to do it long enough to diagnose.  If I let it cool down for about 10 minutes, I could start it and drive home.

Haven't had any time to put any serious mileage on it, but right after the swap I did a successful 200 mile loop without dropping any cylinders.  I think I'll go ahead and send my first unit back to Dyna for them to test.

DavidR.

[jscgdunn]

For about the last year or so, I've had a chronic problem of the 2-3 coil dropping out on my '85.  Coincidently, it also has a Dyna 2000 ignition (and coils, and wires).  A few weeks ago, I swapped out the ignition box for a spare unit that I had. 

It would run for hours without a problem, then I'd roll off the throttle to slow down.  When I'd pick the throttle back up, the tach would drop to 0 and I'd be running on 2 cylinders.  Couldn't get it to do it long enough to diagnose.  If I let it cool down for about 10 minutes, I could start it and drive home.

Haven't had any time to put any serious mileage on it, but right after the swap I did a successful 200 mile loop without dropping any cylinders.  I think I'll go ahead and send my first unit back to Dyna for them to test.

DavidR.

Have you replaced fuel filter....?

[Derek Young]

Dreadrock:  The flapectomy Dan is speaking of is the vent for the fuel tank.  Its a figure 8 shaped plastic piece inside the fuel tank cap.  If you have an early model fj without a fuel pump, you should definitely consider changing it. If it isn't the problem now, it will be eventually.  It does sound like you have a coil issue as well.  Some folks on here have taken off the dyna gear and only use stock ignition parts. 

Derek

[SlowOldGuy]

For about the last year or so, I've had a chronic problem of the 2-3 coil dropping out on my '85.  Coincidently, it also has a Dyna 2000 ignition (and coils, and wires).  A few weeks ago, I swapped out the ignition box for a spare unit that I had. 
SNIP

Have you replaced fuel filter....?

It's an '85, no filter.  And it's definitely not a fuel problem.  This is an electrical shutdown.  No bucking or lagging or stumbling, the tach goes dead and I'm running on 2 cylinders.

Called Dyna today and will be sending my original ignition unit in for "evaluation."  We'll see what they find (hopefully something!)

DavidR.

[DreadRock]

I was wondering about the fuel filter so thats out . I picked up a new set of coils from dyna hope thats itas one was bad so now have a spare but who knows . 

[yamaha fj rider]

DreadRock I know this won't change the tachometer problem but could you also have some water in the gas? I have seen strange things like this with just a little water in the fuel. Hope this helps? 

Kurt

[DreadRock]

Dont think so but will look it over. Last night i pulled the carbs rack off to check and make sure the PO had atleast some kind of jetting . The carbs bowls were very clean and rejetted and waiting to get new cables from randy at RPM ! Im tring to go over everything i can think of befor taking the bike out for a long haul . So i dont know how to know if there is water in the tank but there isnt much gas in it now so might empty it seeing as i have the tank off the bike and put fresh fuel in it !

[yamaha fj rider]

DredRock when you have the carbs off check/clean pilot jets and mixture screw passages Blow these out with good carb cleaner. This will eliminate most carb problems.
Hope this helps. 

Kurt

[RichBaker]

Drain it into a clear glass or gas-proof container, let it sit for a couple hours and you'll see a definite dividing line between water and fuel.... Ethanol can only absorb so much, if there's enough water to make it run funky, you'll see it.

[DreadRock]

 
Long story short ....
put new coils on the bike
put new throttle cables on the bike
put new battery in the bike
Rode down to store and ran fine  headed over to buddys house tand see if i can get it to break down well it did . Right as i was pulling into his house so they heard it to. So pulled tank off and seem the way the fuel line was routed was causeing the fuel to lock up. Rerouted it so it was right and put tank back on and took it out . Ran great for about 8 miles and started to bog as i pulled back into his house. And was running but bad so after it wascooled down started it back up and was running bad again till tilted the bike to the right hand side and just started to running good again.
So this leads me to think :Fuel  Seems the bike is running or starts fine but when it gets hot leans way out .So after it sat for a half hour started it up to ride  home  got about a mile down the road and dead again . Tried to turn in over but just cranked so push it back to buddys house. Where to now ?
Where can i find online how the Dyna set up works and how to adjust it ?
Could it be a fuel flow problem?
Maybe the gas lid ?
I really have enjoyed the bike even if it only 5 to 9 miles at a time but want more LOL