want to confirm next steps after smelling gas from oil filler opening

I forgot to add that after I shut it down yesterday, I did pull the plugs. They were wet. I left the plugs out and walked away. One thing I can think of is that after I did the running synch and colortune, I drained the gas from the carbs to do the electrical work. When I reconnected the temporary supply, I did tap on the bowls and I could have sworn that the gas stopped flowing. I haven't yet opened/smelled the oil filler cap for gas.

I'm stepping away for a couple of days and just trying to lay out my next steps to diagnose the problem.

@Timbox , I'm in Minneapolis, so LaCrosse would be a bit of a drive. If I get it running, I'd happily cruise SE Minnesota/SW Wisconsin and meet along the way.

 

Ok, starting from square one.

I testing al for plug and I have spark. Next, without removing the carbs, I checked the fuel levels in carbs 1 & 2. Number 1, was high enough that it was more than just an improper setting. At first, it looked good, but as I held the tube next to the carb, I could see the level slowly rise higher. Number 2 looked fine. I then drained the bowls for 1 & 2 and re-checked them. Even tapping on the bowl, I had the same reading.

I know I need to take the carbs off again and look at number 1. Either a stuck float or a leaking valve (though they were just replaced).

Is there anything else I should be looking at?
Does this explain the cold exhausts for 1 & 2?

 

Kosel,
If you have not taken those carbs to "Church" all the way, you can not be sure what the fuel issue might be. There are so many little passages, holes, rubber getting old and cracking it is hard to track carb issues when the job is only done a little bit. I would guess that if you don't take the time to take the carbs all the way down, clean and air blast all the jets and passages that you might be chasing issues for a long time.

When you tested the fuel level did you have the bike on the center stand? Most of us have build some type of stand to mount the carbs to. I hung mine from ratchet straps and then made sure they were flush and plum.

Once thing you can try, with the books off the back side of the carbs (air box side) you try to start the bike and then put you palm on the back side of the carbs of the cylinders that are not running. That might put enough force inside the carbs to brake lose any plugged areas. That is just to see if you can get it running. You will get some extra fuel that comes out the back side of the carbs when you do this. Keep us posted..

 

I took the carbs to church. Completely disassembled, soaked, scrubbed, replaced all the seals and o-rings and gaskets. All the carb parts, including new needles and seats came from XJ4Ever.

When I first set the fuel levels, the carbs were mounted on a homemade stand and the carbs were leveled. When I checked yesterday, the bike was on the center stand.

The bike ran last weekend when I did the sync and colortune. The current issue happened after I replaced the fuse box - I disconnected the temporary gas supply and drained the bowls to do the electrical work.

 

Looks like you found your trouble, the fuse box. I would go back and do a continuity check with all your connections. Good work on the connectors and how you have them bent and connected, very well done.

This is just a suggestion but I would go back and add heat and solder them. As the wire comes though the little tunnel of the clip, you can put the tip of the solder iron on the clip side and add the solder. It will wick into the wire and on the connector for a elctro mechanical connection.

The only other thing I can think of is just a trouble that started new and was bad timing as you did the fuse box mod. You would have to work your way from the plugs back through the wires and the coils.

Beast of luck and keep of the good work.

 

I hear ya man.... My carbs have been off 10 times in the last month, myself to blame I guess. But I replaced all the needles and set levels in a leveled test stand and it just seems to randomly change. I think the bike bouncing along allows the float to move better and you might get a slightly different level than just sitting stationary. I take the bike for a 2 min. ride and check again, now I have #1 not firing (cold) at start but it gets going when the rpms increase so I'll be tweaking that one tonight, think it's high and runs rich like yours starting out. I'm crazy frustrated to just get it back to where it was a month ago...

And now all that beating on the intake boots have given me vacuum leaks (I believe)... new boots arrive soon.

What's more... the bike ran really well for three weeks and I dropped it at the shop for a rear tire and it came out running badly. Kind of like why would a fuse box make a difference? I think if a needle is leaking very little it's when the bike sits the flooding builds up over time. Or they whacked something... I don't know....

 

I'm thinking that draining the carb bowls to do the fuse box is what caused the current fuel level issue. I'll tackle the number 1 fuel level and see where that gets me. Before I re-mount the carbs, I'll leave them in the rack with the temporary fuel line long enough to convince myself they're not leaking.

Once back on, I'll re-do the running sync and colortune. Then, we'll see what's next.

 

I'm at my wit's end.
I replaced the float valve assemblies with all metal from XJ4Ever, trimmed plug wires, got cables hooked back up and started it up. It eventually started, but didn't run right. After a minute or two of idling, headers for 1 & 2 were cool, where 3 & 4 were getting hot.

Right after I shut it down I checked a few things: fuel levels were within spec; plugs were wet; did not smell gas from the oil filler hole.

Despite all of the work I've done on it this past summer, this is the same problem that's been plaguing me all season and has kept it on the center stand in the garage. I'm just not sure what else to try.

 

You have a colortune plug? Put it in Cyl 1, then 2; watch what's happening. Could be waaaaay too rich, while 3 & 4 are much leaner (and thus hotter). Maybe they're missing, or not firing at all? Being able to physically SEE what's happening in there will be very helpful.

Keep in mind you can turn the electrode in the colortune plug, make sure it's somewhere you can see the actual spark, vs. just the combustion, then you know you're getting a reliable spark if it's not combusting thus leading to the assumption that, combined with the wet plugs, your carbs are pushing too much fuel - so much you're outside of a combustible air/fuel mixture.

Haven't read back over the thread to check, sorry, but have you tried physically swapping the coils/wires so if it's a coil/wire/cap issue, it should move to Cyl 3&4? (if you have, just ignore this)

 

I used a colortune earlier and I thought I did everything right, but will try that again. First, I'll confirm where the mixture screws are set. I haven't adjusted them since July, when I last fired things up.

I assume swapping the coils/wires means swapping 1 & 4 and 2 & 3. I'll try that, too.

 

I swapped the coils, so that the plug wire number ran 4-3-2-1 (left to right as you sit on the bike). Headers 1 & 2 remained cool.

I also checked the number 1 carb mixture screw. It was 2.25 turns from soft seat.

I will try the colortune plug next, but am not really sure what I'm looking for. is it the timing of the spark? Color? Intensity?

 

I think what Windterdark is looking for is the color of the colortune when it sparks. He thinks you are running really rich.

If you have changed over the plug wires from the normal 1-2-3-4 to 4-3-2-1 you might get a different reading. Let us know if the header pipes are now hot on 1-2 and cool on 3-4 with the wire swap.

 

2.25 turns out would be lean. Baseline is 2.5, and typically you'll end up with them at 2.75 or so.

 

Pipes 1 & 2 remained cool, even after swapping the plugs/coils.

Winch seems to weigh against Winterdark's thinking.

I'll try the colortune after work. Anything else I should be looking at while I'm at it?

 

Well, I am shaking my head a little too now, the trouble is not following the trouble shooting. Have you already taken the connectors apart and cleaned them on the bike? I would re-check that coil connectors as well. I think when we swapped the coil wires around we were hoping the different cylinders would start to fire.

If you have fuel in all the carbs and you have spark on all the plugs then it makes sense that your bike would fire and run. Tired I need to sleep on this one.

 

I've separately swapped the positions of the wires and plugs, so that would seem to point to either the engine or the carbs. The b1tch of it is that things ran fine for an afternoon. I know I had all 4 firing back in July, before I replaced the fuse box.

Since I just got another Seca 650, I'm thinking of taking those carbs to church and then swap them out. It means this season's a loss, but it should (should!) confirm or eliminate the carbs as the problem.

I'll still listen to any advice anyone has on what else to try or look at.

 

Tried a new set of spark plugs (or swapped plugs between "OK" and "Dead" cylinders to see if the problem follows the plugs?

 

I swapped the plugs after I returned the coils/wires to their original cylinders. No change, still cool headers on numbers 1 & 2.

A friend dropped off a compression tester. Would it make sense to check compression?

Right now, my plan is to remove the carbs from the "new" Seca, take them to church, and swap them out. Hopefully I can at least get it started before first snowfall. Of course, being in Minnesota, that could be as soon as next week.

 

Yes!

 

Checked compression, but I am not sure what to make of the numbers. My Haynes manual says the compression numbers are for the UK model only.
Cylinder 1: 130
Cylinder 2: 120
Cylinder 3: 125
Cylinder 4: 122

Anyone have any insight?