Fellas and Fellettes.....new to the forum but have been riding forever. My current ride is finally causing some problems...need a little friendly advice. Bought my '02 Road King Classic (fuely) new in '02. Standard Stage 1 mods....SE air cleaner, V+H slip-ons, and HD Stage 1 fuel map. I've got ~33K miles on the clock but haven't ridden much for the past couple years. Active military duties have called me away far too often. When stored, I put Stabil in the tank. When I get back, run it dry and refill with fresh fuel and a little Seafoam. Seems to have worked well for the past nine years. Anyway, the bike has been great all this time until recently.

Symptoms...stammers and stumbles (coughs) under partial throttle periodically. Not all the time. Sometimes it'll go 40+ miles without a cough, sometimes not. The best description I can give is that it starts to cough like a carb'd bike does when you need to switch over to reserve....seems fuel starved. Being a fuely with a full tank of gas, obviously that isn't the case. Fuel pump is fine, pulled it and replaced the filter and line last spring at 30K. Pressures up and shuts down as it's supposed to. New battery a month or so ago....ouch...$185! Does NOT pop any codes or CEL so it's probably not electronic or an actual misfire condition. The only pattern I can seem to distinguish is that it runs rougher and coughs more frequently when it's hot outside. For example, this time of year it's cool here in the mornings (around 50*F) but has been warming up pretty good by the afternoon (~75*F yesterday). The bike ran like a raped ape on the 45 mile trip to work in the morning. On the way home, after about the first five miles it started coughing periodocally.....got worse the more I rode, even died at a stoplight for the first time ever. It doesn't backfire, only normal popping on deceleration but it has popped through the intake a couple times. Again, seems to only happen at partial throttle....rip it open and it goes.

My gut tells me it's an intake leak. Possibly a partially fouled injector or leaking injector seal. Did the WD40 leak test (nothing unusual noted) but ran out of time last night to pull the plugs to check for a lean condition but will tonight when I get home. Don't have the money to bring it to the dealer for $200 worth of "troubleshooting time" to end up telling me it's fine....again. Besides, I'm a firm believer in doing your own wrenching....I trust myself more than "some new guy" at the shop.

So, I throw myself at your collective wisdom. Thoughts, ideas, or solutions?

Thanks in advance for the advice.

 

First of all, welcome to the forum.
It looks like you were pretty thorough. My thought was the fuel filter but you changed that and tested for intake leak. One thing did stand out. Some of these symptoms are the result of bad battery connections. I see you replaced the battery but go back over all the cables, especially the ground cable where it attaches to the frame.
I know it sounds simple but it's easy and costs you nothing.
If nobody else chimes in on something that helps you, try posting in the touring section.

 

Nevil....thanks for the quick reply. Yeah, thought about that when I changed the battery. I actually went through every single connector plug, fuze, and relay on the bike at the time....unplud/replug. I'll recheck the grounding cable tonight when I pull the plugs. Please correct me if I'm wrong, but wouldn't a bad ground throw a ground fault DTC?

I've been chasing this gremlin for a while....getting frustrated with it. Unless someone comes up with a "exactly that happend to me and this is what fixed it" idea, my plan is to throw some intake parts (seals, gaskets, and o-rings) at it in the hopes that it's something cheap and relatively easy. My gutt still tells me it's an intake leak.

Gotta get it rolling again....diesel fuel prices for my truck are KILLIN' me!

 

It should throw a code but you never know.
Have you checked the fuel pump line in the tank? They have been know to get pin hole leaks and that would affect your fuel pressure and flow.
Wish I could be of more help. You probably don't want to hear this but I've been fighting what I think is an intake leak since mine was almost new. After replacing intake seals 2 time, once by a dealer and once by my indie, and seeing that the seals were fine, I'm pretty convinced there is an issue with mating surfaces between the throttle body and jugs.

 

Fuel line in the tank...yeah, replaced that last year when I did the filter. In diagnosing that issue, most of the time you can hear spraying inside the tank when the fuel level drops below the pin hole or the pump just doesn't shut off due to lack of pressure.

Mating surface is a possibility if it warped somehow during overheating. Presumably, they replaced and properly installed your intake flanges when they did the seals. I haven't got that far yet but likely will soon.

It's usually pretty cool around here, not much in the way of stop and go traffic, and I run syn oil so overheating is a minor concern for me unless it's way leaned out...again, brings me back to the intake leak thought. Chicken and egg argument comes to mind....

Thanks and keep the ideas coming...been scratching my head on this one for a while, any idea is a good idea at this point.

 

Belay my last ... didn't get far enough into the thread ....

When you figure it out, be sure to post the source of your problem for the benefit of others ....

R/
'Chop

 

Last belayed. Thanks 'Chop....will do. I take it you're the Chop for one of our local commands. I've had a lot of time in Everett over the years. At Whidbey now but head back to Everett in January.

 

Previous tour was DH ride in FORD ...

My previous post was to tip you to the possible pin-hole leak, right about the time Nevil was posting the same thing ... by the time my post hit, it was OBE ....

 

Yeah, thanks again Chop...already been down that road. Not it. Ford....back a bunch of years ago they used to call her Stalag 54.....: ) Not so fun at the time...guess it got much better. I'm a squadron CMC, headed to NAVSTA for one more tour in Jan as I mentioned. After that I'll have to find a "real job".

Anyway, for the collective wisdom....checked grounding wires, all good and tight with no corrosion or wear. Pulled the plugs...both are showing signs of hot/lean mixture....light grey/white....super clean, no nasty deposits, no blistering, no cracking, and no physical damage. They were new last year too, gap is about where I left it.

Still thinking it's an intake leak....hopefully it's that simple. If anyone has a clue, please chime-in. Out of town for a while coming up, have to tear into it after I get home. Any suggestions will be greatly appreciated.

 

Welcome to the board and I'd say go with your 1st instinct. The intake seals would not seat on my 2000 FB carb and I got new flanges and seals for under $10 thru my Indy from Custom Chrome. I don't have an EFI but I've read that the throttle position sensors need cleaning from time to time. Might be a good time to pull the intake apart, replace those parts and give everything a good cleaning.
Good luck!