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Steve, Motorcycle Mechanic
Category: Motorcycle
Satisfied Customers: 6992
Experience:  30+ yrs. experience, MMI, HD technician, HD early, engine rebuild/performance, bike builder, kit bike program manager, CCI 2001-2004
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I have a 98 road that stopped running, it threw a map sensor

Customer Question

I have a 98 road king that stopped running, it threw a map sensor and tps sensor code. I replaced both then found it was only running on one cylinder. After further inspection the front jug had a pushrod that had backed off and was loose not allowing exhaust valve to open. I adjusted it and it ran great for a little while. Then I hear the "clatter" that sounds like a bad lifter. Also though when trying to ride the bike it falls on its face. Could this be a collapsed lifter?
Submitted: 2 years ago.
Category: Motorcycle
Expert:  Steve replied 2 years ago.

there is no way to know without pulling it out.

you might have lost a tappet roller, a cam bearing, dirt in the lifter or a worn/collapsed lifter.

I would open the gearcase and inspect everything.

IF you find ANY debris in the area of the hole for the oil pump return, you MUST remove the oil pump and inspect for debris as well.

let m know if you need more help.


Customer: replied 2 years ago.
Thanks Steve, I know there is no absolute way of knowing with getting in there, maybe I asked the wrong question. So the bike will run on both cylinders but it will cough out the front intake port (loading up) essentially I think there may be a problem with lifter/ cam because all pushrods are adjusted properly. Here's my question, in your experience does this seem the likely problem area? I don't think its electrical as the map, tps, ets and crank sensor are all new. Not many magnetti marelli gurus in my area. Even my local Harley shop told me I was pretty much on my own because it was trial and error with those intakes and they couldn't scan the bike.
Expert:  Steve replied 2 years ago.

an intake cough is a symptom of a LEAN MIS-FIRE.

in MM injected bikes, the causes may be leaky intake seals or a problem with the engine temperature sensor.

both are common problems.

to determine if the problem is leaky intake seals, spray carb cleaner on the intake seals with the engine at idle. you will know right away if you have leaky seals.

if not leaky seals, then I would consider replacing the engine temperature sensor. it is located in the front head sticking straight up through the center of the rocker cover. you don't have to remove the fuel tanks to change it out, but I would suggest you do that if you decide to replace it.

- note: HD no longer supports your EFI system. your best bet, for ease of maintenance and long term reliability is to strip the fuel injection and replace it with a carburetor and standard EVO ignition.

if you are considering this option, let me know and I will provide more detail.


Customer: replied 2 years ago.
I stated in my last rant that I already replaced ets (engine temp sensor). I have checked the intake seals for leaks with carb cleaner it doesn't change the idle.
Expert:  Steve replied 2 years ago.

an intake cough is a symptom of a lean mis-fire.

if your intake seals are good and you have a new engine temperature sensor, you should consider dyno tuning the engine to correct the lean air/fuel ratio causing the mis-fire.

this should resolve your original question.

- another thing.......multiple sensors never fail all at once. it just doesn't happen. when multiple codes show up all at once, typically, the ECM has or is about to fail.

let me know if you need more help.


Customer: replied 2 years ago.
The bike originally only had a tps and map sensor code. I did the engine temp sensor while I was at because they are know to fail. I also re gasketed both rocker boxes. The bike definitely had a sensor issue because it wouldn't start up at all at first. Then I got it to run on one cylinder. Then after further inspection and a very bad front intake port cough I found a pushrod had backed off. This was not allowing exhaust valve to open causing the cough. The fuel had no where to go. Now it runs on both cylinders but has slight cough and some chatter coming from front jug. Do you think this is the ECM? I've inspected it about a week ago with no corrosion at all. Also the bike only has 15k if that throws any flags up.
Expert:  Steve replied 2 years ago.

we don't seem to be communicating.

I'm going to opt out.

best of luck.


Customer: replied 2 years ago.
I've noticed that's been your response to other people on here. I seem to be communicating fine. I'm responding and asking questions. Giving you all the info I can.