Question about Harley Davidson FXST Softail Standard Motorcycles

1 Answer

87 fxst with screamin eagle ign module. When idleing timing retards and slows idle down to very slow chugging (galaping horse) sound. Turn up idle screw it will speed up to a faster chugging (galaping horse sound) then give a crank on the throttle and return to a too fast idle, wait a minute and magicly drops back down to the to slow galaping horse chug again. When it idles fast timing dot is in the hole and when it chugs the timing mark disappears and a line shows up in the hole(advanced rear cylinder mark). Voes is new and closes at 3 inof vacuum. tried pumping up voes to hold it in closed position and idle still does the same thing. I think some thing is the module is retarding the timing a low rpms.

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Brigadier General:

    An expert that has over 10,000 points.

  • Master
  • 4,565 Answers

Well, to begin with, I don't think your Evo flywheel is marked with an "advanced rear cyl." mark. It has a Top Dead Center mark, another mark at 20°, and an "adv. front cyl". mark. The 20° mark is used by the dealership to set the timing. I don't know how they do this but I always use the Front Cylinder Advanced mark to time the engines. For a description of your timing marks, go to Crane Cams' site and look at their installation instructions for an HI-4 Ignition unit. Go to the last page (pg.8) of the instructions and it will show you what the timing marks look like. Here's the page:

Now, there is no telling what can happen with anything electronic but what I'd do is disconnect the VOES electrically. I wouldn't just pull the vacuum hose, I'd either disconnect the plug where it plugs into the ignition system or disconnect the ground to see if that makes a difference. This is just to rule out the VOES switch which I don't think is the problem.

I ran into this problem once before on a 1989 FLHTCU with the stock ignition unit on it. It would revert to "initial timing setting" when the engine was idling. It would roll the timing back to just before TDC (about 5° BTDC) whenever the engine would idle. I suspect the it was the engine speed sensing circuitry inside the unit that was bad. It didn't know the engine was running, just that the ignition switch was on. Since there is no real way to test the unit, we simply replaced the ignition system and the problem went away. Sorry I couldn't help you more.

Ride Safe

Posted on Apr 10, 2011


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

87 Chevy pickup 305 has very high idle but runs great other than that. I've try tuning it down by turning the distributor had it sounding nice but no power on take off any thoughts

With the later model cars and trucks that are computer controlled, fast idles often means that there is some sort of vacuum leak in the intake side of the engine. Turning the distributor will slow the idle, but it also changes the engine timing, and this will result in the loss of power you are experiencing. The catch-22 of this is that now, until you can find and fix the source of the intake leak, you won't be ale to effectively reset the timing to the correct position.

Dec 29, 2014 | Cars & Trucks

1 Answer

1996 eagle vision 3.5

EGR valve may be stuck closed allowing pinging . The Knock sensor can also go bad and not retard timing allowing pinging also . Heavy carbon buildup in the combustion chamber can increase compression causing pinging .

Sep 01, 2017 | 1994 Eagle Vision

1 Answer

1996 camero v8, after running car and it gets warmed up it quits runnung, after it cools off it starts with no problem??

check your coolant tempurature sensor. sounds like the symtoms of a bad sensor.--- poor cold idle, stalling, ( rich mixture) retarded timing, slow idle speed, cold hesitation or stumble, poor fuel milage, will also ****** timing. hope this helps!

Jul 26, 2011 | 1996 Chevrolet Camaro

1 Answer

2001 chevy venture stalls when first starting to drive cold and only when cold have scanned it and replaced the map sensor due to not holding vac have looked for bad ground as the turn signal lights in...

its a possibility that you have a bad coolant tempurature sensor. symtoms of a bad sensor are: poor cold idle, stalling, ( rich mixture retards timing ) slow idle speed, cold hesitation, or stumble, poor fuel milage. remove and clean idle air control also, ( IAC ). good-day!!

Jul 15, 2011 | 2001 Chevrolet Venture

1 Answer

Major hesitation at cold idle, car accelerates at a slow pace, hesitation also appears when in passing gear. replaced fuel filter 2 months ago

symtoms of a bad coolant sensor: poor car idle, rich mixture, retarded timing, slow idle speed, cold hesitation or stumble, poor fuel milage, check and make sure air filter is clean. and check plugs and wires if need be,

May 02, 2010 | 1992 Honda Accord

2 Answers

My car is idling way too fast. I can't get it to

Sounds like your IAC (idle air control). Its located on the throttle body.

Dec 19, 2009 | 1995 Eagle Vision

1 Answer

Rough idle and slow take off at any light. Hardly any horse power

sounds to me like vaccum issue. unless its fuel injected, then probably check your fuel pressure regulator.

Aug 16, 2009 | 1993 Ford Ranger SuperCab

3 Answers

99 olds alero 2.4

I'm sure you have installed a fuel pressure gauge and monitored the fuel pressure while the problem is occurring?Another diagnostic tool which is easy to do,is while the problem is occurring,unplug one sensor at a time beginning with the Mass Air Flow first,.if it uses one.Many times,not always,depending on the sensor,if the sensor is taken out of the picture as far as what the PCM is seeing,like unplugging the MAF,the PCM will substitute the missing sensor output with a generic value that will allow the engine to at least run,and if unplugging for example the MAF,the engine idle speed returns to normal,you know you're onto the problem.You didn't mention if the engine ran ok other than the idle problem.As far as checking for vacuum leaks,i use something like brake cleaner or WD 40,more of a liquid,and it does sound like a vacuum leak.Plastic intake manifolds do develop nearly invisible cracks that open up more with heat.Revsisit the possibility.And as for the PCM,it is possible,but more likely a mechanical problem.Lastly,remove an O2 sensor or two before the catalytic convertor,run the engine and see if anything changes.Cheap way to verify the catalytic convertor is flowing and not restricting engine airflow,as i have seen bad cats cause misfire codes and strange problems.Good luck.

Dec 03, 2008 | 1999 Oldsmobile Alero

Not finding what you are looking for?
Motorcycles Logo

Related Topics:

231 people viewed this question

Ask a Question

Usually answered in minutes!

Top Harley Davidson Experts

Arnie Burke
Arnie Burke

Level 3 Expert

4525 Answers


Level 3 Expert

4340 Answers


Level 3 Expert

76164 Answers

Are you a Harley Davidson Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides