Brand new S&S problems

[4x4ford33]

So I put a ton of money into my chopper recently, new ignition/coil, rewire, rebuild .010 over, pretty much all new parts. I have a 113" S&S with the new rebuild, I test drove it before I brought it home and it ran/runs very well. The problem is now I'll ride it and won't even be able to get to the end of the block without it stalling. The stall sounds like it is running out of gas, but once I stop and wait 10-20 seconds it will start back up and again run fine until it stalls again after the same amount of running.

I spoke with the guy that built it and I've tried replacing the fuel line/ petcock as well as cleaning out the gas tank and fresh gas. I have a flush mounted gas tank cap and thought the tank wasn't venting properly thus stopping the flow of gas. Does anyone know how these caps vent?

Tried replacing the coil/spark plugs. All of the electrical components are ultima, programmable ignition with single fire coil. Now our thinking is that the ignition is bad but I would like to rule out everything else first. My coil is mounted on a mount that is chrome and is bolted to the cylinders, and the ground wire is just bolted to the back of that mount, is it possible that that is a bad grounding spot and would cause this?

I was hoping to find someone who has had a similar problem or someone who could recommend some ideas. Any help is appreciated, I need to get out and ride this thing.

[Batto]

is it a pop top type cap that you screw out or the type they have on jap bikes i have a pop type that has a hole on the top and one at the bottom with a allan head screw that can adjust air flow. if you have an in line fuel filter disconect it and see if that clears i had a filter there once and needed a pump to push fuel through. good luck mate enjoy your rides.

[pushrod243]

It sounds like a venting issue.......try running a hose from the petcock into a gas can and see if it stops flowing. If it does pop the cap open and it should start flowing again

[DarinZ]

"My coil is mounted on a mount that is chrome and is bolted to the cylinders, and the ground wire is just bolted to the back of that mount, is it possible that that is a bad grounding spot and would cause this?" ??? Do you mean batt ground or your trying to ground a wire off the coil? Cause as far as I know the ultima single fire coil doesn't get grounded anywhere.

[RB Donovan]

To me it sounds like one or two different problems.
The first, the main breaker is popping off. An easy check for this would be no power to the headlight, tail-light, or brake light. Check to see if things are non operative as soon as it shuts down. If all shuts down then the main breaker is very suspective.

The second would be vapor lock. Re-routing the fuel line away from heat generally solves this problem.

The next suggestion I would have is to try riding with the fuel cap either off the tank, or very loose. If it keeps running without shutting down then you have pinpointed the problem, (bad venting).

You can check ths last suggestion and the first suggestion at the same time.

[4x4ford33]

The gas cap is one that screws in and then you push the top down and turn it so it flush mounts, but I don't see anywhere on the cap that would vent but the bike ran fine before with this same set up. Also there wasn't a fuel filter in the fuel line, I put one in temporarily to check for fuel flow which appeared ok to me, as in the filter never went dry. I tried running it with the gas cap off while sitting there and it still stalled.

The ground wire doesn't come off the coil it comes from my main loom, but it is grounded where the coil is mounted. I shouldof been more clear on that but my frustration is building with this bike.

The fuel line does run out of the petcock and directly between the cylinders to the oppisite side of the motor to the bottom of the carb so maybe it is a heat issue, I will have to try to re-route it in the morning. Also I'll have to check for power to the headlight immediately after it quits, I have checked but it was after a few seconds so it may have had enough time to pop back. Does the main breaker re set itself?

Thanks for all the ideas guys, I find going over everything with some educated ears to be very helpful with troubleshooting. This bikes been down for about a year and it's so close to being ready to ride I just want to ride.

[4x4ford33]

It's a gas tank cap that screws in and then the top is pushed down and turned to make it mount flush, but I don't see any holes or anything that it would vent through. I only put a fuel filter on it now to check for fuel flow so I don't think that's what it is. Also I have tried running the bike with the fuel cap off and it still stalls.

I think I didn't expalin the ground very well, it's not a ground from the coil it just grounds behind the coil. The wires come from the main loom of the bike but it doesn't seem like a great place for grounding.

Also I checked the headlight when the bike stalls and it is still on, I checked it two different times. I also re routed the gas line away from between the cylinders and ran it above them, and I thought it helped because it seemed to idle better without stalling but I went to take it for a test drive and I only made it about two houses down before it stalled.

Thanks for all the help so far guys, it's been over a year and I just want to get back to riding.

[Batto]

have the spark plug leads been taken off a lot lately can you check them with a multi meter and when you do bend them to see if they lose continuity they may have a crack in them.,,,, how hot is the motor getting as your ignition maybe shuting down if it gets to hot. the ground should not worry anything. good luck mate.

[Skydiver]

Take the gas cap off ride it around the block and see if that cures the problem.

[4x4ford33]

The spark plug wires are brand new so hopefully their not the problem. I rode it with the gas cap unscrewed and completly off the bike and it still stalls on me.

I pulled off the ignition cover, it's a ultima programmable ignition, and the status light blinks the whole time it's running and when it stalls and continues to blink even after it stalls. Could the ignition be the problem, it's brand new and has about 10 minutes of ride time on it. I don't think it's a heat issue seeming if I start the bike and take off it will still only make it about 2 houses down the block, maybe 100 feet.

[madmastiff]

wow-wee

some times people cheapen up when getting a fuel line and use too small a size cuz its clear and pretty. but it restricts the flow. works great at idle, sux when trying to drive.

get a bigger line and see if that works, if not then look at the carb it may be too small/big for the engine

[DarinZ]

I'd check and make sure there's nothing in the needle and seat. Sounds lime your sucking the bowl dry before it fills back up?? Are you sure you have that ultima ignition wired right. You should only use 3 wires. White= positive post of coil Pink= negative post of coil and Blue= negative post of coil. The other voes wire and tach wire should be taped off. I don't think that red light should be flashing when the engines not running only when it's firing at tdc. Maybe the over current protection or over heat protection is kicking in. I'll have to go read the manual.

[DarinZ]

The manual says if the red status led rapidly flashes with the bike not running a over current or short circuit have been detected. Check and make sure the coil was wired properly. Make sure dip switch #6 set correctly for single fire or the dual fire modes.

[Skydiver]

I still think you have a fuel delivery problem not electrical. You said it starts right up again after 10-20 seconds.

[06 pitbull]

has anyone mentioned a kinked fuel line or colapased fuel line?? I still think john mentioned disconnect the fuel line from the carb & allow it to drain in a seperate tank.. watch the flow... possible the fule line has something in it... only allowing small amount of flow. possible debris of broken rubber parts... its a easy check..