The bike will treat you fine if you learn about it.
The factory service manual is a useful tool along with this forum.
Older bikes just need someone that will care to learn about the bike by reading a couple of sections in the service manual.
I think reading and maintaining your own bike is a useful experience for a motorcycle rider.
Most dealer techs see 100's of 1-5 year old bikes for every one or two 20+ year old bike so working on your own bike becomes kinda/sorta the way to go.
Since you are mechanically able and have the desire, your motorcycle will be kept in very good condition.

 

Thanks for this. Yes one of the first things I did after purchasing the bike was get the factory manual for it. Doesn't matter what I own, I get the book for it!

 

Test the voltage of the sensors. The TPS should be .275 volts with the throttle blades fully closed. There's more. I would learn it.
Another thing to consider is resale value of a bike with this ECM. The Delphi is light years better. So is a carbed system. Most are well aware of this.

 

Only if it's an EVO Marelli. If it's a Twin Cam it's a different value. .275V is tossed about as the value on all Marelli's and that is incorrect. As the OP has a 1999 you have given him a value that is not where the system wants to be.

 

what is the correct value then? I have seen and heard the .275v many times and if thats not it i would like to know what the correct value is

 

.175 to start but .195 was a sweet spot - especially if it has slip ons or is a 95" kit.

 

I have a 2000 with MM. My advice is simple: If it's running well, leave it be. Don't tinker with it, don't try to adjust it, don't try to dial it in. Don't even look at it! Just ride it and enjoy it. And if possible, try to buy backup parts ASAP on eBay.

 

Is has basically been circled around but not stated cleanly in my opinion…the short answer is nothing is so terrible with the MM EFI…No O2 sensors to mess with!!! A Very basic EFI system relying primarily on throttle position and crank position…the long answer, like stated above, is the long standing history repeated over and over ‘they are junk, put a carb on’.

That is truly a silly statement, only made because you CAN do that with a MM system…why does no one suggest that today with the late model Twinkies or M8? Because they CAN’T.

Talking about the MM system in 2023-24 does not take into account the Harley owner in the late 90s…No YouTube, no Google, No FB, no message boards or forums…in short no knowledge about this newly introduced EFI system that requires proprietary equipment and training to understand. Like others have stated, if it works leave it be…that’s what the owners of the 90s couldn’t do…just like today they like to tinker and modify their rides…they could tune a carb with a jet kit that was readily available at every MC shop, but Flash an ECM just because I changed exhaust or air cleaner…a dealership charge??? Give me a break…and oh by the way, a 90s rider that attempted to adjust the TSP was just asking for a tow…so that’s it…we have come to live with EFI…expect to return to the dealer for a Flash when we want to upgrade to stage I or II…expect to buy a tuner…expect a sensor or fuel pump to crap out…but the 90s rider couldn’t compromise the simplicity of gravity feed fuel, the availability of a jet kit, and the familiarity of a carb!!!

Little did the 90s rider know, the EPA didn’t care and EFI was here to stay and a few short years later, completely replace carbs…complete with requiring O2 sensors, ergo Delphi!!!

 

Well written answer and one I would tend to agree with.

 

For those who think the Magneti Marelli fuel injection is garbage, consider that it may well be that the ECM that *controls* the Magneti Marelli is where the trouble lies.

Here's a video of a cold start on my 2000 FLHCTU/I with a ThunderMax. ECM. Yes, I had to install O2 sensors on the head pipes but that's not particularly challenging if your welding game is up to snuff or if you have access to a shop that can cut/weld for you. I did the latter and my cost was sub $200 for their work.


I chose to go the ThunderMax route after modifying the engine (S&S 100" kit plus S&S 570 Easy Start cams). I was just not able to tune the factory setup to start and idle smoothy. This would be overkill on a stock engine. Yes, I considered going to a carb but preferred to stick with fuel injection, and didn't want to bother going the route of a Delphi upgrade. Very happy with the decision.