I bought a 98 Road King EFI about 5 years ago. It had the Stage I and II kit on the bike as far as we could tell. I put SE Heads, Pushrods, Tappets, High Compression Pistons, SE Slip-ons, PC III USB and an SE-57 cam in the bike 2 1/2 years ago. I'm on the vurge of a mental breakdown. I've spend so much money and time having it "tuned" and adjusted that is would make you sick. It still runs like total crap. Erratic Idle, hard cold start, poor throttle repsonse, pings all the time. I'm to the point where I'm either going to sell it or spend some even more money trying to get it running right. I've been told by most of the dealerships that have worked on it that the Magneti Marelli EFI is crap and there's nothing I can do with it other than change it out to carb or install a closed loop fuel management system. Both which are expensive. Anyone have any advise or similar problems?
I have an almost identical build on my FXR4 and it runs like a sweetheart. Big power (over 90 at the rear wheel) and dead reliable. 30,000 miles on the build so far. I did have to replace and upgrade the rocker box gaskets this winter but that's not too bad to me. The main difference I see between your build and mine is I have a 42mm Mikuni. I love that carb. I've heard nothing very good ever about the Magneti-Morelli FI. It's hard to know if that's your problem or not. I will say that my engine was built by a real master mechanic and I'm sure that has a lot to do with its reliability. Still, those Mikunis are great carbs and easy to tune. I'd be looking at converting that funky FI for a great carb. You'll also need either a Mik air cleaner or equivalent. The Mik might very well cure the cold start, erratic idle, and poor throttle response. They're famous for that. I think I saw a complete Mikuni kit in one of the catalogs (J&P) with A/C and cover, carb, manifold, and all the parts to convert for about $600. Personally, I would have gone straight to the Mikuni and left the MM FI on the shelf.
You don't say anything about what your ignition is (mine is SE) but your pinging could be from overheating because of poor fuel metering or just bad ignition stuff like too much advance or wrong advance curve. Also remember with your build you can not just putt around town like on your average bagger and expect all to be cool. It won't put up with running under 3000 rpm in the upper gears. You'll get pinging if you do. Guaranteed! By the way I'm just guessing your compression ratio is 10:1 or better. That's what you'd have with SE pistons.
Thanks for the info. I have about 20,000 on the rebuild and has never ran right from the day I got it home. The bike came stock with the MM FI but all these shops keep telling me they can make it run and everytime I get it back there is really not a lot of noticable difference. I would have never ever converted to an EFI had it not been on the bike when I bought it. I've got people telling, intake manifold gaskets, head gaskets head temp sensors. The last Dyno I had put it at 70 hp with 80 ft-lbs. For as much as I has in it and for a 10.5:1 comression that bike should be pulling 90+ also. I'm not real sure what the ignition system currently is. I had it built at a certified harley shop but that's not saying much these days. Putting isn't in my vocab. I thought I built it to run and run hard. My buddy has the same bike, same year, same EFI, with on the stage I and II kit in it and his bike puts mine to shame when we leave lights. It's pretty frustrating to say the least. If you remember where you seen that conversion kit drop me a line so I check into it for sure. I think a carb conversion is the way I'd like to go but I don't want to spend another $1,500 to $2,000 getting there. Thanks for the response>
J&P Cycles. In their '09 catalog it's on p. 439. Part #400-681. It's the Mikuni "Total" kit. $578.99.
Whether or not this is the magic bullet for your bike...don't know. I know you've had it at some shops but if they haven't diagnosed the problem correctly you haven't been to the right shop. Your bike should be pulling at least 80hp.
The pinging makes me suspect ignition too. Someone needs to get that figured out and dialed in.
I took a look at that Mikuni Kit but I think theres going to be more to the conversion that just changing out the MM EFI to a Carb. Fuel tank petcock, wiring etc. Have you seen a kit that includes all the required wiring harness changes fuel tank chanes etc. I may just have to take it into a shop. I have a guy that has been coming very highly recommended but I'm a little hesitant as the last three harley dealerships that have had it told me the could fix it. at $300-$400 a pop for tuning etc its gets pretty expensive. I think you might be onto something with the iginition though. I took it out last night and ran her up to about a hundred in fourth gear and she just started pinging like no tomorrow. I swicth into fifth and she would run over about 105-108 and still pinging to be the band. That bike should easly bury the speedometer without doing that. When I put a even the smallest load on it its does the same thing. I guess I may just have to take another $300 plung and see if they can do something with it it as is although I'm to the point where I just want to say screw it and find someone to do the full carb conversion for me. What cam are you running in yours?
If all your components are NOT defective and were installed correctly, and it doesn't seem that there are any compatibility probs, then your parts/components are simply sitting there waiting to be used correctly by the 2nd point..
Fuel delivery and ignition which you already suspect..
The pinging (detonation), whether at top-end or off-the-line, is caused by in-correct setting-up and tuning for the parts/components at hand..
Hi-Compression makes Correct tuning even More important..
Doing the Carb conversion would be a great thing but, since it seems that you are Not your own Mechanic coupled with the issues you've brought up about the change-over,, you end up right back into being dependant on some other dude that poss has No idea how to set you up.. Follow me..??
Miks are My Fav but require Hands-On tuning.. If a guy tries to tune it for you, even if he's familiar with them, he cannot know what you're really feeling in the seat of your pants so he cannot really tune it correctly.. You can only hope he gets close..
If a guy IS NOT familiar with Miks well then, you're right back at square one..
Ignition is the same prob, it must be right-on and running Hi-Comp definately means Timing has to be Correct..
Final thought..
I bet a dime to a dough-nut that, even with the components/parts you're running, if it was set-up & tuned correctly you'd be much happier..
Where do you live.? Maybe someone here knows a good Mech in your area..
__________________ "Fill your hands you son of a bitch"
Rooster Cogburn
I appreciate everyones input. I live in Omaha, NE. All points well taken. I'm going to take all this info into the shop when I go. I've been told that Clifford Cycles here in Omaha is the best in the area. Of course I found this out after I've had it Dyno 3 other times at other shops. The bottom line for me is that it should run a lot more consistent and hard than it does. When I was shoping for a bike 5 years ago, I definetly knew I wanted an EVO because of there reliability and stamina. I absolutley don't want to part with the bike but this whole tuning issue has brought me to me whits end. My buddy has the same year with the Stage I and II kit in it with a PCIII USB also and he leaves me in the dust most of the time. I have an appointment with Clifford's next Wednesday and I plan on taking all this info with me to hopefully sort it out. I'm not apposed to dumping the EFI unless it won't run the way it should with all the work I've had done. Milindh said he has the almost identical build and he's pulling over 90 HP at the rear wheel. Last output sheet they gave me at the dealership I was pushing a smig less than 70 HP.
Right move JT. If you can't diagnose your problems yourself you need a wizard to help you. I'm betting you have a problem with fuel delivery along with an ignition thang. It doesn't seem like either one of those by themselves would add up to your conditions. Together they might. At any rate a good mechanic will go through your whole engine and figure it out (hopefully). Don't change to a carb until you have an accurate diagnosis of the real problem(s). Changing parts without knowing the root problems is a surefire prescription for a lightened wallet and tooth gnashing frustration.
For what it's worth the parts in my FXR4 are:
SE heads
SE pistons
SE57 cam
SE pushrods
SE ignition
Mikuni 42mm Carb, manifold, A/C
V&H Hot Shot 2 into 2 tapered megaphone pipes (loud!)
So those are the parts. I attribute both the high horsepower and reliability of the engine to the guy that built the engine. Careful assembly and tuning knowledge are the magic ingredients here. Good luck in finding your own wizard.
98 Road King Perfomance Problems 
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