Engine stalling on 1985 interstate

[leejames]

it will run fine, then it stalls. Not every day. At first was thinking bad gas. Used 0% ethanol, ran fine for three weeks, then started stalling again. Sunday, i changed thr fuel filter. It still stalled. Every now and then I get a backfire when trying to restart. Any suggestions

 

[joedrum]

welcome to classic ...it could a lot of things but it seems maybe ignition trouble and cutting out at tempeture ...and then running after cool down ...1200s have front ignition triggers and the black box that can cause trouble black box mostly ....maybe new wires will and ends could cool things down ...something getting heated up ...next time it happens take the plugs out carefully when hot and check for spark before it cools down much

 

[Ansimp]

Welcome from Oz

 

[backlander]

Howdy and welcome to CGW. Like joe said, could be a lot of things, ignition, carbs, vacuum leaks, loose intake runners, vacuum ports on carbs loose, 1200's also have anti-backfire valve on bottom of air plenum with vacuum lines all underneath the rack, so start with the easiest to do checks first, oh and check to make sure your choke or carb enrichers are closing fully when the engine is warmed up, sometimes they don't automaticaly close all the way like they should. It also could be contaminated fuel or fuel tank.

 

[slabghost]

Try running 6-8 oz of atf in a full tank of fuel. Seems like carb trouble to me.

 

[Omega Man]

Welcome to the forums leejames! We'll help ya sort it out.

This is the Introduction section of the forums so I'm going to move your thread to the "General Forum" so the the tech questions/answers/diagnosis stuff can begin. :yes:

~O~

 

[toytender01]

Check to see that your choke in in the off position. It will probably run great in the full on position, just idle high. Don't ask how I know this. :smilie_happy: :smilie_happy: :smilie_happy:

 

[mwbill37841]

welcome from tenn. what they said.. :good:

 

[Bobo]

I'd first run 1oz./gal of fuel of Seafoam through one or two tanks. If it "runs fine" until it stalls, then the channels in the carbs should have flow and I'd just clean out any "carb boogers" that might be roaming around in them.

And I'm really thinking you've got an intermittent vacuum leak. Have you replaced the large O-rings at the bottom of the alum. intake elbows? If they're original they're flatter than pancakes and should be replaced. That's the first place I look for vacuum leaks in Wings of our vintage. Inspect the upper connections of those same elbows for soundness and tightness, too.

This is why I like to synchronize my carbs at least once per riding season. Not only is carb synch'ing important to getting the most balanced performance out of our Classic Wings, but it's an easy way to check for vacuum leaks, by cylinder. You do it when the engine is warmed up anyway, but I leave the gauges attached for another 10-15 minutes after adjusting the carbs to let it get warm enough to kick on the fan and warmer, check the vacuum at idle, but also at 2,500 rpms and hold it there, an approximate road speed.

 

[Joep]

Easy check for vacuum leaks in areas not easy to access... use wd40 with the straw attached and spray joints and based..and hoses you can see while running. If rpms surge there is a leak.. no surge is a sealed area... Did you replace fuel lines when replacing the filter? ... I recently bought an 85 interstate... and even with a new filter I could smell gas... had a split line from the peacock only the split was in the end of the house but not to the out side of it... More like a cut in the inner sidewall... replaced lines with 3/16 tygon for weedeater.... and the filter to the pump also....... does it restart right after dying on you? You might want to pull the petcock off and drain the tank through that hole.. do it when tank is low.. you could have crud hitting the petcock pick up screen.... just my $.02..... this sounds like fuel issue... could be coils or ignitors if heat issues.

 

[zman]

Sure sounds like excessive fuel since it runs good sometimes, maybe a float needle hanging up intermitently.

 

[Steve83]

Welcome from Southern California! All good advice so far!

 

[Bobo]

Joep » Tue Oct 08, 2013 10:12 pm[/url]":3636qkfn]
Easy check for vacuum leaks in areas not easy to access... use wd40 with the straw attached and spray joints and based..and hoses you can see while running. If rpms surge there is a leak.. no surge is a sealed area... Did you replace fuel lines when replacing the filter? ... I recently bought an 85 interstate... and even with a new filter I could smell gas... had a split line from the peacock only the split was in the end of the house but not to the out side of it... More like a cut in the inner sidewall... replaced lines with 3/16 tygon for weedeater.... and the filter to the pump also....... does it restart right after dying on you? You might want to pull the petcock off and drain the tank through that hole.. do it when tank is low.. you could have crud hitting the petcock pick up screen.... just my $.02..... this sounds like fuel issue... could be coils or ignitors if heat issues.

I prefer carb cleaner to WD-40, but then I'm impatient! :Egyptian:

 

[slabghost]

Also open the tank cap the next time it stalls and see if it will start back up. The cap vent might be near plugged.