Engine/carb issue with xj650 maxim '82, please help

If it runs fast at idle it's pulling air in somewhere - simple as that. No engine will run without air. You should, if you've set the bench synch carefully by lining the plates up on the edge of the hole be able to get an acceptable idle straight off.
A running synch will be the icing on the cake.
If it runs too fast you've got air going in one or more butterfies - check all close fully against the light - are they centred properly? Set all carbs to the edge of the first hole, make sure all the enrichners are fully seated and none damaged. Check all the manifolds are sealed to the head and at the carbs.

 

195 for 80-81 205 82-82 pilot air jet.

 

Tomorrow I’m going to take the carbs off and try to line them up exactly as you have said. I know they’re all very similarly angled and close almost if not all the way in the body. I think the first time I used light shining through the carbs to synch them, instead of using that top hole as a reference point. I’ll be surprised but more than happy if that does the trick.

 

You see, that post tells me all I need to know. "Very similarly angled" and "close allmost if not all the way in the body"
Both these statements are not good enough I'm afraid. Each plate individually must close tightly on its own, every time without fail - have you managed to mix up the plates - they are not all the same apparently and definately only go in one way.
Once each plate is centred and closes fully you can then set no3 with the screw to the edge of the most closed hole. Then move out the rack on either side to the other carbs, and repeat. You need good light and eyes. Closing the idle screw should close all 4 together. Once happy set it one and a half turns open ( guessed starting point only, this will change once its idling). Make sure the manifolds are all sealed, the vacuum port plugs are all sealed and start it up with the enrichner. As it warms let off the enrichner, you may need to close down or open up the idle screw to keep the rpms tame as this goes on.

 

I finally am not having as much difficulty starting the bike (set the wet levels and did a proper bench synch) besides some electrical issues. my main issue now is that the idle runs away to 3k to 6.5K and I cannot get the choke off without it dying on me. I have done basically everything you have done and I do not have pods thankfully. I hear those are such a headache!

 

that top hole trick made a difference for me and I wish I would have done that first.

 

[QUOTE=" As it warms let off the enrichner, you may need to close down or open up the idle screw to keep the rpms tame as this goes on.[/QUOTE]
so I can slowly let off the enricher but cant fully turn it off, so you suggest to turn the idle screw to compensate for it? I havent tried that and if that is all I need to do that sounds easy enough!

 

Ok, thank you! Just to be clear, after getting the rack off the bike I individually tune each carb (starting at 3, and then moving outwards doing 2 before 1) so that the plate just covers the fuel hole at the top of the venturi? and then try closing them all the way with the idle knob and push it out about ~1.5 turns to get t to a starting point from which to adjust?
I really hope this solves my issue, and at the very least I think it will help. Honestly though do you think this issue could cause a 7k runaway idle? I'll post updates after

 

yes you start with three, you use the idle knob to get it placed over the venturi as is pictured earlier in this thread and then you go outward adjusting the others to be as similar to the third carb as possible relative to the venturi

 

You want to set idle mixtures right? How are you going to do this if its not idling? Actually, first off you want to get it running low enough to do a running synch - and whichever way you look at it that needs to be without the enrichener. If that means you need to tweek the idle control, then mixtures, then idle control - do it!
If you have no idea what the mixture screw settings are doing set them all the same and move them all the same, no more than 1/4 turn each at a time until the warm engine is idling.
Then do a running sync, and if you have a 4 gauge set you'd better be sure they give you the same reading on the same port - ie are accurate, or if not accurate - oh hell you need to back to back test them thats all.
Once you've done the running synch go back to the idle control, bring the speed to where it should be, do the running sync again, over and over. Then tweek the mixture screws, all together, to get the fastest smoothest idle. Then do another running sync (all this can be done together in minutes by someone who knows what their doing and is methodical, so dont let it put you off, and dont take shortcuts).
Finally, once you think you have it near right you should think about a colourtune to set the mixtures ( I hate them, never used one since I threw mine into the toolbox in dismay), I use my ear to listen for a drop, then by turning the screw the other way, a rise, and eventually a throbbing drop, then back to somewhere in the middle.
Oh, get a fan, even a desk one, to blow over the motor, otherwise if you're slow at this you will overheat the oil.

 

That's not a venturi, it's a progression hole. And don't set it "over" it, set it at the edge, right at the edge. Sorry if I wasn,t clear on that.

 

And if We're being pedantic here, you check and set each carb fully closed, making sure it does, individuually before doing any adjusting (by now you should have worked out that you have to adjust the idle nob on No3 and the sync screws on the others to allow this) snap them open and closed a few times to check they all close first, then start the bench sett process.
Remove my appology, I did say "edge" of the hole.

 

sorry it was my mistake, I knew that was the correct way to do it but misspoke in my communication of it. that trick is far easier than the paperclip/card method

 

Little things are all it takes to upset these things, the amount of air and fuel needed for idle is tiny, so details matter.

 

so if I am able to get the enrichment half off and the idle is dropping with it that would mean that the bike isn't getting enough oxygen and thus I would need to turn open the idle knob?

 

Either that or the mixtures are all way weak. Reduce the enrichener slowly, turn up the idle knob until the enrichener is all off. Then try screwing mixtures out to see what happens. iwould try to get it idling somewhere near right before synching.

 

Okay I’m setting the butterflies to just cover the front edge of that progression hole on all carbs so that the hole is NOT visible. Then I back the idle knob (and thus all 4 carbs) out about 1.5 turns, or until about half of the most forward progression hole is visible.
Is the procedure above correct? Depending on response time and how quickly I get this done I may start with only a sliver of the progression hole visible, to err on the side of less fuel/air flow and lower rpms

 

You don’t have to play the card game OR use paper clips
1. Set carb 3 with the butterfly juuust on the back edge of the hole at the top of the butterfly.use the idle screw to do that
2. Now, use the sync screws to adjust the other three to the same spot.
(3. I snap the linkage a dozen times at this point)
4.back the idle screw out until carb 3 hole is covered HALFWAY
5. Double check that the other three are also half way. Now fine adjust until all are half covered after snapping again several times.

you are now bench-synced. It took you longer to read this than it takes you to do it. It usually takes about 1 minute to do.

per hogfiddles!

 

Well what I was suggesting was that once all exactly parallel you back off the idle screw until all are closed, then open a turn and a half. Either way, the important thing is to get them as close as, with the idle screw somewhere near close to where it needs to be - exactly where that is is not vitally important, you can screw in in or out as it warms up. I think @hoggfidles said it takes no longer to do than read his procedure, maybe not for him, but it does me.

 

Wow! It works! Or it worked for like a half hour until the electrics cut out (hopefully an entirely separate and non-related issue). I did the procedure the right way (thanks to Minimutly, NikoRx, and hogfiddles) and it started on its own (no starter fluid) and idled at 1.5k. Amazing. Now ive got to go charge the battery and figure out what went wrong there. But progress nonetheless