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Efi carb convo

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Old Jan 18, 2016 | 10:20 AM
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Default Efi carb convo

Ok, after struggling to get the stupid MM efi to run properly I am ditching it for real this time. Wish me luck with the conversion. 1998 Ultra Classic
 
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Old Jan 18, 2016 | 10:34 AM
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I have done the same conversion on a 1998 Ultra Classic and it is worth while. I used the Ultima 53-644 ign and a an s&s super e. The hardest part is drilling the fuel lines out of the tank. I would suggest using a later model tank without the steel lines if you can.

I ended up going to a 9/16 drill bit from underneath, you have to be real careful not to booger up the threads, as you will need them for the pingel kit.

Let me know if you have any questions. I struggled with it at first (mostly the timing) but got it down now.
 

Last edited by flhchaz; Jan 18, 2016 at 01:57 PM.
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Old Jan 18, 2016 | 11:54 AM
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Thanks, expect plenty of inquiries.
 
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Old Jan 18, 2016 | 12:26 PM
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Originally Posted by Plumbwader
Ok, after struggling to get the stupid MM efi to run properly I am ditching it for real this time. Wish me luck with the conversion. 1998 Ultra Classic
What exactly is the trouble?
Rather simple system.
Most forget to check the crank position sensor connector that gets loose near the ecm and causes weird stuff.
Some folks have changed-out the system but never addressed the simple to fix loose connection.
Others have the engine temp sensor fail that causes surging since the ecm flips from hot to cold rapidly when sensor is bad. Changing sensor resolves problem.
The fuel lines that leak or delaminate from inside to outside. Easily replaced with Goodridge HDfl005
The cam position sensor melts and causes hard starting if original. Use HD replacement.
Dirty throttle body.
or the piece of loose tank liner that clogs fuel intake.
It is a rather predictable system if you read the one chapter in the service book.
Unfortunately very few techs want to spend the time in reading the one chapter.
The parts are still available.
Nothing wrong with going carb but sometimes it is less expensive and less work to address a simple issue.
 
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Old Jan 18, 2016 | 12:52 PM
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Originally Posted by im
What exactly is the trouble?
Rather simple system.
Most forget to check the crank position sensor connector that gets loose near the ecm and causes weird stuff.
Some folks have changed-out the system but never addressed the simple to fix loose connection.
Others have the engine temp sensor fail that causes surging since the ecm flips from hot to cold rapidly when sensor is bad. Changing sensor resolves problem.
The fuel lines that leak or delaminate from inside to outside. Easily replaced with Goodridge HDfl005
The cam position sensor melts and causes hard starting if original. Use HD replacement.
Dirty throttle body.
or the piece of loose tank liner that clogs fuel intake.
It is a rather predictable system if you read the one chapter in the service book.
Unfortunately very few techs want to spend the time in reading the one chapter.
The parts are still available.
Nothing wrong with going carb but sometimes it is less expensive and less work to address a simple issue.
i cant get the cold or hot idle to be consistent. Also it decel pops like crazy and stalls at a stop after coming off of a long highway run. I guess, maybe, it might be a fine system if you are willing to tinker around with it but i am far more comfortable with a carb. Not to mention the Harley carb lope. That is an awesome sound that cant be duplicated with efi. I know that performance wise that is meaningless, but it sure sounds cool.
 
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Old Jan 18, 2016 | 01:51 PM
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Originally Posted by Plumbwader
i cant get the cold or hot idle to be consistent. Also it decel pops like crazy and stalls at a stop after coming off of a long highway run. I guess, maybe, it might be a fine system if you are willing to tinker around with it but i am far more comfortable with a carb. Not to mention the Harley carb lope. That is an awesome sound that cant be duplicated with efi. I know that performance wise that is meaningless, but it sure sounds cool.
Not to mention that you can fix a carb on the side of the road.
EFI not so much.
 
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Old Jan 18, 2016 | 01:52 PM
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Remove the top access panel and look inside tank for a loose piece of tank liner.
Tank liner piece releases from center and floats to fuel suction.
That creates a repeat problem when throttle is closed and piece floats away but later gets sucked back into position causing fuel obstruction.
Regardless of carb or efi that will create a problem.
A decel pop could be a leak at the throttle manifold or at slip-on mufflers and it would pop even worse if pipes are straight with no baffles.
It would be similar for carb or EFI so you may wish to consider reviewing.
The cold and hot idle could be dirty air bleeds or engine temp sensor and a combination of adjusting them without stable parameters first.
The loose crank position sensor connection explained earlier would cause bike to back fire over bumps or when coming to a hard stop, speedometer would drop for a moment also.
Not much tinkering, but more of known items that once addressed properly will make the bike trouble free for thousands of miles.
The neat thing about old bikes is the wealth of information available.
Just providing the information, many are a free fix and would allow for you to ride confidently until you make the change desired.
 

Last edited by im; Jan 18, 2016 at 01:55 PM.
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Old Jan 18, 2016 | 01:56 PM
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I've done a 98 Classic before also and we swapped out the tank as it was WAY easier to deal with than the internals.

Used a Screaming eagle ignition. CV carb I got for $5 at a swap meet and rebuilt it for him. He ran it about a year and dropped in a 113" motor like I had in mine at the time. Made that swap real easy to do.

Griz
 
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Old Jan 18, 2016 | 02:13 PM
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Between all of you guys, my buddies, and i, i know I can get this done. I really wanted to make the MM efi work but after already dropping $350 on new fuel lines and manifold gaskets and constantly adjusting it im just completely over it. Carb all the way. i just cant think of a viable benefit to continuing down the road with the efi.
 
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Old Jan 18, 2016 | 02:34 PM
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Originally Posted by Plumbwader
......i just cant think of a viable benefit to continuing down the road with the efi.
There are lots of those, however we can help ya with the carb conversion. We feel your pain! I have two EFI and one carb bikes and they are all fine - and all capable of giving problems which can drive ya to drink if we don't get a hold on things.
 
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