I have a 98 500e and last summer I did the following.

     K&N lunchbox
     V&H full exhaust
     Rejetted 150/40/2 washers/ tuned to around 3ish turns out
     Bob's ignition Advance

        Before doing this my Idle wasn't the greatest but I thought it might just need a tune up.  After I was finished it still didn't idle right, I don't know if it has gotten worst or if I'm just getting more frustrated.    Anyways my spark plugs are firing all the time but for some reason my right cylinder is not running at idle.  If I turn the idle up enough for it to not die most of the time time at idle, the rpms will stay up around 6k after I rev it and I will have to put in into  gear and use the clutch to bring the rpms down.  Runs decent above 3k rpms.  I thought it might be my pilot jet so I replaced that one with another size 40 non bleeder.  That didn't help so I tried putting the stock one back in then replaced it with the size 40.  I took it to a bike shop in town and he's telling me that my signal rotor is bent and not firing that cylinder but I can tell that side is getting spark at idle and is firing fine above 3k rpms.  Also if I take the cover off and spin the engine over the signal rotor doesn't seem to wobble at all.  I don't know what else to check.  Could it be that the ignition advance is a little off and that cylinder isn't getting spark at the right time during idle but somehow works fine at higher rpms?  Should I go buy a new signal rotor and try that?  What Suggestions do you guys have for me?   Thanks a lot for your help I wanna get back on the road.

Oh yeah and last time I had my carb apart I blew air and then gas(with a syringe) through the pilot jet just in case it was clogged.  It seemed to be going through there pretty well.

I was also looking at pricing for a new signal rotor and there are two at oem part website's.  One says (E33) next to it how do I know which one i'll need if I do need it?

Thanks again,

Neal

Have you already tried swapping the coils and/or swapping the plugs, to see whether the problem switches sides?

Have you checked the wiring and connectors for the battery / alternator / regulator-rectifier /  coils / plugs to make sure everything is "clean"?  There may be a slightly dirty connection that prevents a good spark until the revs go up and the voltage increases to a certain point. 

Have you done resistance checks on the spark coils and the signal generator coils?

It can be a couple of things.

1. How many turns out is the idle mixture screw for the right carb.
2. Did you do a "visual" sync of the carbs or have you synchronized the carbs?

The part where you say that if you rev it up the engine won't come back to idle usually means that its too lean at the idle condition. Hence question 1.

To verify that its not the spark try the following, rev it up to 3K(obviously when the bike is in nuetral) and pull the right plug of the cylinder. If the RPM drop and it starts to run rough then you know the spark is good. Now repeat at idle, if it doesn't do anything different then you know that its for sure the right cylinder and that its probably not getting enough of either air or fuel(hence questions 1 and 2)

Idle mixture screw for the right carb is right around 3 turns out.  If I have my idle set to keep it at around 1200-1500 rpms then pull off my right plug wire nothing happens.  If I'm revved and pull off my right plug wire it bogs and rpms fall.  When I had it in the shop they sync'd the carbs for me.

If I get the mixture right and turn my idle down it will not idle but will run great above 3k rpms and not stay revved.  It only stays revved when I have to turn my idle way up to keep it running at idle on one cylinder.

I have put new plugs in it, swaped the plugs to no effect.

I think I need to buy a repair manual and follow the spark from the alternator on through the plugs.  Will a repair manual explain doing a resistance check on the coils?  I don't know what that is?  Should I be getting the same amount of voltage to my plug wires at idle as I do at higher rpms?  Wouldn't this be an easier way to check and see if I have a bad connection somewhere?  If so what reading should I get if I take volt meter to it? 

Thanks for the posts guys,
Neal

I honestly suspect the carbs or a fuel air mixture issue.

What happens if you just crack the throttle open from 1K-3K and compare with right plug cap off and right plug cap on.

The question that I have is, how much do you trust your shop? You can visually synch the carbs by taking them off and looking how much of an opening there is between the carb bore and the butterfly valve on each carb.

Yeah I don't really trust the shop I went to.  Seemed like they picked something to be wrong and didn't want to find the real problem.  They were like we think it is your signal rotor but with 16k miles on the bike it wouldn't be worth it to fix.  Now that I've looked up how cheap that rotor is (40-60$) I realize they probably had no clue what they were talking about and didn't wanna spend time finding the problem.

Just about everytime I take the carb out I've looked at the butterfly valve's and they seem to be in the exact same position as each other, but who knows.  Also first time I started her up after installing everything I think she idled ok and I tuned it using the revving/bogging technique on one of the gs sites and ended up around 3 1/4 turn out on each side, each time I put it back together I position my idle screw from 3-3 1/4 turn's out.  It should run ok even if this is not perfect so I don't think it is my mixture.

Cracking the throttle should have the same result as turning the idle screw right?  I have in the past turned the idle way up to get it to actually idle around 1500-2000 rpms and when i do this taking the right plug wire off has no effect as long as it is under 3k rpms.

If I take my right plugwire off and connect it to a new plug thats gapped correctly and grounded while my left cylinder is idleing the bike.  If the right wire is making the plug spark then my issue has to be gas or air correct?  I think that might lead me in the right direction on what to test next.

Neal

Quote from: TwinsRFun on February 17, 2008, 10:19:37 PM
Yeah I don't really trust the shop I went to.  Seemed like they picked something to be wrong and didn't want to find the real problem.  They were like we think it is your signal rotor but with 16k miles on the bike it wouldn't be worth it to fix.  Now that I've looked up how cheap that rotor is (40-60$) I realize they probably had no clue what they were talking about and didn't wanna spend time finding the problem.

Just about everytime I take the carb out I've looked at the butterfly valve's and they seem to be in the exact same position as each other, but who knows.  Also first time I started her up after installing everything I think she idled ok and I tuned it using the revving/bogging technique on one of the gs sites and ended up around 3 1/4 turn out on each side, each time I put it back together I position my idle screw from 3-3 1/4 turn's out.  It should run ok even if this is not perfect so I don't think it is my mixture.

Cracking the throttle should have the same result as turning the idle screw right?  I have in the past turned the idle way up to get it to actually idle around 1500-2000 rpms and when i do this taking the right plug wire off has no effect as long as it is under 3k rpms.

If I take my right plugwire off and connect it to a new plug thats gapped correctly and grounded while my left cylinder is idleing the bike.  If the right wire is making the plug spark then my issue has to be gas or air correct?  I think that might lead me in the right direction on what to test next.

Neal

That why I feel its a fuel/air issue and not a plug issue.

Have you checked for vacuum leaks using the old WD-40 trick. The little o-ring under the black plastic piece is there, and the vacuum caps.

Other thing that just came to my mind is the valve clearances. Have they been checked recently?

The little o-ring under the black cap is still there.  Where are my vacuum caps located or supposed to be located, it's a 98 model.  Also can I check vacuum leaks with wd40 with it barely idling?

Neal

Edit:Oh yeah forgot to mention my bike will die if the fuel petcock is not turned to pri.  I've check my fuel vacuum hose and connections there ok and haven't done anything else about it cause it runs fine in the PRI position.  Don't know if this info pertains to my problem or not if not I can fix this issue at a later date.

Quote from: TwinsRFun on February 17, 2008, 10:19:37 PMIf the right wire is making the plug spark then my issue has to be gas or air correct?

Not necessarily.  Back when my bike was running on one cylinder, I was getting what I thought was good spark on both sides.  In retrospect, the "bad" spark was more yellow than blue, but both plugs were definitely firing.

After finding and fixing a corroded connection in the signal generator wiring ... ShaZam!  If you're interested in my experience and some tips on testing, start at [THIS POST] and work through to the bottom of the page.

Cool thanks  for clarifying.  I was actually reading that post through the night at work.  What do you think is faster checking the coils with an ohmmeter or switching them?  Probably gonna try and check them with an ohmmeter later this week if I can't figure that out I might just switch them and see if my problem switches side.  Thanks man.

Neal

If you have an ohmmeter, the quickest thing for the signal generator coils would be to measure their resistance values from the 3-wire connector near the battery.  I don't think you can profitably switch those particular coils.

As for the ignition / spark coils, it's more of a toss-up.  Given their awkward position under the frame, it's not a bad idea to remove them before you take measurements.  And once you've got them off, swapping them doesn't take much more effort.  (It's been a few years since I goofed with these coils, so my memory of the "awkwardness" may be somewhat inflated.... )

They are a PITA to get at, but it'd probably be a bit easier if I'd taken the tank completely off. 

Quote from: Kerry on February 18, 2008, 03:17:37 AM

Quote from: TwinsRFun on February 17, 2008, 10:19:37 PMIf the right wire is making the plug spark then my issue has to be gas or air correct?

Not necessarily.  Back when my bike was running on one cylinder, I was getting what I thought was good spark on both sides.  In retrospect, the "bad" spark was more yellow than blue, but both plugs were definitely firing.

After finding and fixing a corroded connection in the signal generator wiring ... ShaZam!  If you're interested in my experience and some tips on testing, start at [THIS POST] and work through to the bottom of the page.

You learn something new everyday!