Can't get it going. What did I do?

I got my 83 xj550 last August. It ran great but had a dented tank and some other cosmetic problems. I took the tank off along with the 2 plastics and had them painted. Looks great (I will post the pics when I get my problem solved).
Anyway, I put the tank back on (put in gas) and got everything hooked back up. I tried to start it and it wouldn't. So I rechecked everything I could think of and still no starting it. By now the battery was hurting so I put it on a charge and tried again with the a shot of starting fluid. It was now clear that the battery being charged probably made all the difference because it sounded much better trying to start, and TADAAA she revved right up. Only now it was stuck at 4000 rpm! I turned the choke down and immediately checked the throttle cable and position. I shut it off. NO problem with the throttle. I've since checked the carb boots for any holes or cracks that might be sucking air. Can't find em.
I tried again today after reevaluating, this time without the shot of starting fluid. Same thing, starts right up. This time it started up and seemed like a normal cold start, but once I gave the throttle a little crack it ran up to 4k and stayed there. I've checked some random stuff like the plugs and they are dry, the petcock is in the right position, but I am now second guessing the position of the second (longer skinnier) line from the tank to the carb boot area. I've connected it to the post/valve that sticks up on the third carb boot area. It seems every carb boot has one of these posts with a rubber cap on it (1,2,and 4) except #3.
So I immediately thought that maybe I'm an idiot (well I am) and the 3rd cap is missing and I hooked this line up to the wrong spot. So I just unhooked the line and fired it up again. It still jumped up to 4k, even when I plugged the post/valve with my thumb.
I know I'm overlooking something simple. Sorry the post is so long, but I know it is hard to help when you don't know the whole story. Please let me know if you have questions or have an idea what it is that I am doing wrong.

 

I do believe the vacuum line from the petcock belongs there.

 

have you checked that you have the cables around the right way...

When i put my 900 together I accidentally swapped gas and choke cables and had a similar problem

 

Yeah, I am 99% sure it does go there. But you begin to second guess yourself when you start running out of ideas.

I didn't remove either the throttle or choke cables. So I don't think that is it.

I think that I have to re-check that there are no holes in those boots. That seems like it would make sense. I am going to give them a quick coat of RTV or some other silicone tonight and try to fire it up again tomorrow.

I really appreciate any and all feedback.

 

Welcome to the challenges of getting the carbs set up on the 550's. There are a few things that have to be just right on the Mikunis to avoid these sort of revving nightmares. 1- the float levels have to be just right, can be checked with a clear plastic tube or this method http://www.xjbikes.com/Forums/viewtopic/t=8592/
Then you need to synch those carbs - Bench sync or on the bike with homemade manometer vacuum gauge. There are lots of posts here on how to do this - plus take a look at http://www.youtube.com/watch?v=rNIdhMEHWlU (its not an XJ but you get an idea as to what to do), I use a clear plastic tube with a load of oil in it, taped to a long piece of wood. Then you need to get the pilot jets adjusted - on top of carbs little brass screws that you can adjust on bike. 3.5 turns is recommended but to get one of my XJs to idle at 1000 rpm I had to turn them out 4.5 turns from bottom. The rest of the work for the carbs is cleaning cleaning. Also make sure that the idle adjust screw is turned out a few turns, at the back of the carbs, you can just about squeeze your hand in while on the bike. Get all these things right and you will be twisting that throttle like a WSB pole sitter ready to go off the line....

 

Maybe I should have titled this topic "I can be dangerous with a screwdriver!"...

I have made sure that the boots are sealed by putting a pretty thick coat of hi-temp silicone around them. I don't think there was any leak to begin with but what the heck.

I am sure that all lines are connected properly.

I have attached a pic with 2 different screws outlined. I am assuming the screws with the yellow box around them are the idle/mix screws and the ones with the red box are for making some kind of adjustment to the linkage.

I made the mistake of messing with the screws outlined in red before I knew what they were...

I still have the problem. Matter of fact I have started it several times and it runs up to 4k. if it is cool sometimes it will do the "hunting" thing around 1000 and as soon as I put the slightest pressure on the throttle it revs up.

Is there a small spring that is supposed to prevent the carbs from just opening up? Could I have made this happen when I took all the tension out of the throttle by disconnecting it at the handlebar?

Thank you again for the good suggestions.

 

the screw outlined in red is one of the sync screws. by messing with it, you de-synced your #4 carb from #3. and that's why it won't idle right and shoot to 4K RPM at first opportunity. My 550 did the same thing until it was synced, which is what you get to do now :-D

There are a few helpful threads in the FAQ Suggestions section on how to sync your carbs without breaking the bank. Your bike has YICS, so you'll need to either acquire a YICS tool or make one. There's lots of ideas for that as well in the aforementioned section.

 

DITTO

 

:roll: I guess I got what I deserved... I've seen a member on here with the OH SO memorable signature that has the old "If it ain't broke.." saying. I should have read more of his posts before I started this whirlwind.

I am going to spend some time with it this weekend and I will let everyone know how it turns out.

 

Not that I'm an expert or anything, but for me, when mine was idling way high, it was because I'd turned the enrichment adjustment rod in too far by accident. (On my bike it is a large screw head under the carbs between the second and third) Once I turned it back out again, the idle settled back to normal.

There are also some great tips and complete instructions on this forum on bench synching your carbs.

Good luck.