Starts Great, Idles Great, Runs a while around then dies

Ok I have a 92 xj600. It starts right up. It idles great. I drive around my yard in first and second and it all seems to be fine. So I thought all was well and went to go on a ride and I was going down my side road about 50yards from the house in second gear and it boggs out and dies. I then can barely get it to restart and then just dies again. Then I had the joy of pushing it home. I could get it to start with choke out, but would then die when I pushed back or even tried to drive it with the choke out.
This same thing happened to me 2 weeks ago I thought all was great and got 40yards from the house and it bogged down and died.
So I don't really know where to start at. Fuel pump, carbs?...idk

 

sounds like something is plugged up and surfaces under load conditions. does it happen at a certain RPM?

 

Did you check the plugs?? They could be fouling. Which means a rich rich mixture. Sounds like it if she's bogging while you're riding.
When an engine warms up it becomes more "loose", allowing better travel of fluids and such. So when she's all warmed up and revvin to go, the gas and oil are flowing more freely.
If your plugs are fouling when you're riding I'd suggest cleaning out your air jets again. Could be plugged. Or you may have the wrong Main Fuel Jets installed. A larger Main Jet could cause engine failure because of flooding
Just my MO! I'm no expert
-Chris

 

Sounds to me most like a plugged gas cap vent, or a problem with the vacuum actuated petcock.

Both of these are easy to verify. If it runs OK with the gas cap open, after it dies, then the cap vent is the problem. If it runs OK with the petcock on prime after it dies, then the petcock or its vacuum line is the problem.

 

helmet - It has only happened to me twice and both times have been in second gear about 50 or so yards down the road from my house. So I guess you could say it happens at a certain point.
SLKid- Good suggestion I'll have to look over my plugs and se what they look like. I know I havent changed the main jets. And I doubt the few other P.O.'s have either.
SQLGuy- I just replaced my entire petcock with a new one (my old one was leaking) so I dont think it is that. I'll still check both of your ideas though.
Thanks so far for the replies. Im keeping my fingers crossed. I want to ride so bad. The evenings have been nice here in FL.

 

Yep yep! Always hate to see another riding having probs. Nice to get em fixed!
You may not have to change your jets. Just make sure They're the correct ones for your bike. My PO had 650 jets in mine for some reason. Rebuilt the carbs from a 650 engine I'd assume. Even had wrong needles
-Chris

 

Does it mean anything that I can get it to run after it boggs by having the choke out?

 

Hmm.. Vac leak?? Sounds like an enrichment problem. Did you try SQLs suggestion?? It seems your bike is not gettin enough gas, if thats the case.
Could be plugged gas vent.. Or plugged fuel jets... Try the simplest thing first, then move on to cleaning out your carbs again. Does is bog when you're slowing down? Or when you stop, then accellerate? If it bogs when you're at a stop, could be an enrichment circuit clogged. I know you may have been asked this a hundred times, but, Did you thoroughly clean your carbs?? Thats 90% of our XJ probs. Untuned, unclean carbs.
-Chris

 

It means that your carburetors are overdue for a thorough cleaning.

 

Wheel of Fortune:

C L _ _ N T H _ C _ R B S

"Oooo, No. It's not CLOWN THY CRIBS."

"scizolt. Spin the wheel. Nuthin' but vowels remaining. Vanna even knows the answer. We'd show the people at home; but they know too."

 

Ricky, behave.

 

Ha, you guys are awesome....Rick, should I clean the carbs?

Does is bog when you're slowing down? Nope when I hit 2nd gear for around 20yards then stalls.
Or when you stop, then accellerate? nope

I have not recently thoroughly cleaned my carbs, but I'm thinkin that's what Rick is slightly hinting for me to do.

Well today is Saturday so that means I get to tinker with it.
I'll let you guys know if I find out anything.
thanks for all the tips.....

 

Absolutely.
They probably will just need to be Cleaned and not rebuilt.

Grab yourself a Haynes or a Clymer Book.
You also have to check the Fuel Pump.

 

I finished cleaning the carbs all up. It was cleaner than I thought it was going to be. Just a little bit of gunk. The rubbers that hold the carbs to the intake are cracked really bad. So I will have to get new ones.
I've got the Clymer manual and always use it.
I checked my valves to and they all check out ok.
Any tips or tricks on checking the fuel pump?

 

Ive ordered new rubbers, and am continuing cleaning things up a bit. I'll double check vacuums hoses also. Plugs are dark so I am running somewhat on the rich side. I'll keep this updated as I find more.

 

Guys, I have this same problem. Except my carbs are as close to spotless as my eyes can see. The spark pugs are brand new, I've bench synced it, and it starts, idles, runs, and after riding for a while when I decelerate, and get back down to idle speeds it will just die, not bogg down, it just dies when it approaches idle rpms. I have to add choke to keep it going. When it dies, I usually have to set the tank back to PRI for a minute to get it to start again. Please help, I'm so close to having this bad boy running its making me sick!!!

 

You might have a few things going on.

But, the mere fact that your Bike dies when you get back down ti IDLE Speeds means you have a good bit of Tuning to do to get the Bike too IDLE and not stall.

If the Carbs are "Spotless" as you say ...
>Bench Sync the Throttles with strips of 3X5 Card.
>Turn the Idle Mixture Screws OUT far enough to sustain IDLE with the Throttles Closed.

That will get you started.

 

Thanks for the reply, I've definitely used the 3x5 card trick. Found the problem: the fuel petcock system- it starves for gas on "ON" so when its set to "PRI" it runs like a champ. Nice throttle response: goes up then back down really quickly, and idles like a pro! Except the fact that I need to do a proper sync. Thanks guys!

 

Test:
Manifold vacuum at Port where Petcock Line hooked-up.
Vacuum Line holds a vacuum.
With Line on Petcock:
Place the Vacuum Hose to your lips and draw a vacuum.
Monitor Petcock Flow during Test.
Taste Gas!
Petcock Diaphragm failure.

Open Petcock.
Inspect for slipped Wafer
Debris

Rebuild Petcock (Iffy)
Replace Petcock (Recommended)

 

hmm i have the same ( or close to the same) problem but to get my bike going again i have to sit for a second for the electronics to reset then it will start again ( just noticed that the electronics cut out totaly today when the bike stops ( one mech told me today that it might be a floating gear , no idea how that would shut the engine down) i spent the last few weeks checking the starting system and replaceing things like the starter relay , most is new and can drive my bike around the back yard but when i take it into the ally for a short ride it stalls on me then i just wait for the power to come back and start it then head for the back yard my carbs are clean also guess i should check my vacuum lines next



1982 seca xj650lj (turbo)

 

If you have a Stock Fuse Panel with Glass Fuses and Clips, ... excise the entire Fuse Panel and replace it with a New one.

1982 Bike might need Alternator Brushes

It may be something as simple as a Bad Ignition Switch.
I'm on my 3rd Ign Switch and just topped 50,000 Miles.

I knew it was the Ignition because I got rid of the OEM Fuse Panel when I first got the Bike.

 

brand new atc fuse block in last week but will check the brushes and switch tomorrow ( the switch i am thinking my key does move around some ( 50k klm on the bike sat in a friends garage for 14 year befor i got it ( that is 14 years not started ) he bought it new)

 

Yeah, about the fuse box. Anyone recommend a certain brand or have a link to one they've already installed? Mine is shit... I have tape and a piece of wood holding the ignition fuse in so it doesn't cut out while riding lol.

 

i got mine from a marine store for a few bucks will post a pic today but if you go in and ask for an atc fuse block 4 in 4 out ( or how ever many you need ) you should get one , mine has an o-ring on the cover to keep dust and water out