[Haggis]

I have an Amal with no tps on one of my 500 uce. Still need a battery for sparks though.

[Adrian II]

I was thinking if it was possible to forego the battery and be able to kickstart even when the battery was dead flat. But seems like i'd either have to have a custom stator made or find one that fits. But more pressing of my two questions is How much a difference would it be if i were to fit an AVL TCI into a UCE engine to be able to use non TPS equipped carbs

Probably not very much difference at all! Haggis makes a good point in that the carburettor conversions available for EFI versions of the UCE models use classic old-school carburettor types, either Amal or Mikuni, which have never had TPS and they run just fine, even using the EFI's engine control unit (ECU), which I understand DOES normally use a TPS.

Getting a Bullet OEM TCI to run battery-less is probably not an option, I tried replacing the battery on my old 500 AVL with a capacitor, but the alternator wasn't producing enough output at kick starting speeds to produce a spark. More recent alternators in these bikes have 18 coil stators instead of my old bike's 12 coils so might produce better output at lower speeds. For experimental purposes you could buy a suitable capacitor cheap enough and wire it in place of the battery if you wanted to prove me wrong.

A.

[Monkee]

Probably not very much difference at all! Haggis makes a good point in that the carburettor conversions available for EFI versions of the UCE models use classic old-school carburettor types, either Amal or Mikuni, which have never had TPS and they run just fine, even using the EFI's engine control unit (ECU), which I understand DOES normally use a TPS.

Getting a Bullet OEM TCI to run battery-less is probably not an option, I tried replacing the battery on my old 500 AVL with a capacitor, but the alternator wasn't producing enough output at kick starting speeds to produce a spark. More recent alternators in these bikes have 18 coil stators instead of my old bike's 12 coils so might produce better output at lower speeds. For experimental purposes you could buy a suitable capacitor cheap enough and wire it in place of the battery if you wanted to prove me wrong.

A.

Thats reassuring i guess it wouldn't really matter which TCI i decide to go with my conversion. The reason why i dont want to go the Hitchcock's conversion method is 1. shipping to my country is way more expensive than getting all the parts to replace it with OE components for the conversion 2. I want to keep the stock harness relatively unmolsted if i ever decide to swap back to EFI.

I saw a video somewhat recently of an indian mechanic swapping out the RR not sure what it was but he was able to start the bike without the battery nor capacitor at all. I believe its a RR unit that already has a capacitor in it? Video didnt have subtitles and i dont speak hindi so i wouldn't know. I tried to message their shop directly but they dont want to sell me just the RR unit.

[Adrian II]

I saw a video somewhat recently of an indian mechanic swapping out the RR not sure what it was but he was able to start the bike without the battery nor capacitor at all. I believe its a RR unit that already has a capacitor in it? Video didnt have subtitles and i dont speak hindi so i wouldn't know. I tried to message their shop directly but they dont want to sell me just the RR unit.

Quite possibly, if the newer alternators have a better output at low RPM it could work.

A.

[Haggis]

There is a capacitor built into the R/R unit but it's only there to smooth the voltage. Both my 17 and 18 euro 3 bikes have an external  capacitor wired across the positive and negative on R/R.

[Crabsapper]

But more pressing of my two questions is How much a difference would it be if i were to fit an AVL TCI into a UCE engine to be able to use non TPS equipped carbs

Haven't I already answered that question?

I want to keep the stock harness relatively unmolsted if i ever decide to swap back to EFI.

The stock EFI harness ECU plug won't fit the TCI, nor the stator connector as you need to change that too.
If you want to keep the option to swap back to EFI, keep the EFI ECU for ignition, as per the Hitchcocks method.
As has been shown, that works fine with the TPS disconnected.

[SteveThackery]

If you want to keep the option to swap back to EFI, keep the EFI ECU for ignition, as per the Hitchcocks method.
As has been shown, that works fine with the TPS disconnected.

Yes, that's what I was thinking. The best approach is to do the bare minimum necessary. Disconnect the injector and the TPS; remove the throttle body and fit a carb; job done, isn't it? Ultra-quick to revert.

I don't understand why you would want to ditch the existing ignition system and fit another. It won't work any better.

[Monkee]

Haven't I already answered that question?The stock EFI harness ECU plug won't fit the TCI, nor the stator connector as you need to change that too.
If you want to keep the option to swap back to EFI, keep the EFI ECU for ignition, as per the Hitchcocks method.
As has been shown, that works fine with the TPS disconnected.

You have and thanks. Yeah im aware the EFI harness wont work hence needing a different wiring harness. which im fine with so its this whole direct swap part per part. which i appriciate.

[Monkee]

Yes, that's what I was thinking. The best approach is to do the bare minimum necessary. Disconnect the injector and the TPS; remove the throttle body and fit a carb; job done, isn't it? Ultra-quick to revert.

I don't understand why you would want to ditch the existing ignition system and fit another. It won't work any better.

I could give hitchcock's method a try. but i dont know i guess in my head its easier to have System A vs System B binned separately and not have to faff about with converting wiring or converting it aside from its original design being a whole complete EFI system. Anyway the point of this thread is just to gather some ideas and info from more knowledgable people than myself. Another thing that bothers me with Hitchcock's method is i'd like to use an ammeter instead of disabling the MIL. I dont really mind taking a whole weekend or a day doing it.

[Crabsapper]

Trouble is, if you want a clean conversion, it's a good bit more work. If you want an Ammeter, you really need the appropriate loom.
If you want to go away from the ECU to a TCI, you need to change the rotor (EFI bike has a crank position sensor, not a trigger). This requires a stator change too, as they are different sizes.
You also need to buy or make a fuel pump blank for the tank, plus a tap.
There's a hatful of sensors and wiring tweaks on top, and if you've got ABS that will go too.
It took me a bit longer than a weekend!
Going backwards and forwards is certainly not a desirable thing!

[SteveThackery]

Forgive me, but I am not being rude. I just can't see what the point of all this is.

I can just about see why you might prefer a carb, but why go through all the pain of fitting a TCI when the existing ECU already makes perfectly good sparks?

Personally I wouldn't dream of changing a good EFI to a carb, because EFI works better. The fact that carbs cannot deliver sufficiently precise mixture control says it all.

[axman88]

Yes, that's what I was thinking. The best approach is to do the bare minimum necessary. Disconnect the injector and the TPS; remove the throttle body and fit a carb; job done, isn't it? Ultra-quick to revert.

I don't understand why you would want to ditch the existing ignition system and fit another. It won't work any better.

I think that one would also be removing the fuel pump, and blanking off the large opening in the bottom of their fuel tank with cover that included mounting opening(s) for a petcock for gravity fuel feed.  This is not trivial, especially since Hitchcocks seems to no longer offer the carb. retrofit kit.  Perhaps the blanking plate component is still available, but I can't find it.  And of course, the 02 sensor, temperature sensor, and MAPS (if equipped), would also be vestigial, and could be removed and blanked.

IF I did it, I would do a carb conversion on my C5 the hard way, including replacing the ECU with an alternate ignition for several reasons;
  - I just wouldn't feel right about taping over the MIL light with a piece of electrical tape and ignoring the fact that the ECU was living in a constant state of alarm, having lost contact with many of its sensors.
  -  I suspect that old ECU costs more power consumption than the simpler TCI, especially if one is still heating their vestigial 02 sensor.
  -  The ECU is worth quite a bit more than the TCI, like $250 vs. $50.  If I pull out good parts and cash them in via Ebay, I calculated I would come out a couple hundred dollars on the plus side, even after purchasing the appropriate rotor, the TCI and the carb.  I get to sell the ECU, the fuel pump, the multi-lobed EFI rotor, the throttle body, the injector, and various sensors as spares, all of which are fairly high dollar items, and are, I believe, increasing in value year by year, as is generally always the case with discontinued models.

There is a thread from a few years ago, wherein a knowledgeable member listed all the RE P/Ns needed to do a 500 EFI export conversion "the hard way".  I participated in the thread, but I don't recall the thread title.  This would have been around 2021 or thereabouts.

The blanking plate is the most difficult piece of the puzzle, at this point.  I'm thinking the better solution might  be to modify an IB Bullet tank to mount on my C5, and then sell the EFI tank, which would be another net financial gain.

Most of our members seem to be well heeled westerners, who don't even consider something as pedestrian as saving a few dollars, or selling their unused parts for cash.  Apparently most folks who reported doing the conversion forked over the $400 or so that Hitchcocks was charging for their conversion kit, put their takeout parts into a box on a high shelf, and end of story.  Carb. conversions "the hard way" was apparently quite a bit more common in India, where spares for, and knowledge of, the older model RE 500s is more readily available.

I find it pretty interesting to find the old threads, here on the forum, from the days when EFI first showed up in REs, and reading some of the passionate anti-EFI comments that some folks were making.

[Monkee]

I think that one would also be removing the fuel pump, and blanking off the large opening in the bottom of their fuel tank with cover that included mounting opening(s) for a petcock for gravity fuel feed.  This is not trivial, especially since Hitchcocks seems to no longer offer the carb. retrofit kit.  Perhaps the blanking plate component is still available, but I can't find it.  And of course, the 02 sensor, temperature sensor, and MAPS (if equipped), would also be vestigial, and could be removed and blanked.

IF I did it, I would do a carb conversion on my C5 the hard way, including replacing the ECU with an alternate ignition for several reasons;
  - I just wouldn't feel right about taping over the MIL light with a piece of electrical tape and ignoring the fact that the ECU was living in a constant state of alarm, having lost contact with many of its sensors.
  -  I suspect that old ECU costs more power consumption than the simpler TCI, especially if one is still heating their vestigial 02 sensor.
  -  The ECU is worth quite a bit more than the TCI, like $250 vs. $50.  If I pull out good parts and cash them in via Ebay, I calculated I would come out a couple hundred dollars on the plus side, even after purchasing the appropriate rotor, the TCI and the carb.  I get to sell the ECU, the fuel pump, the multi-lobed EFI rotor, the throttle body, the injector, and various sensors as spares, all of which are fairly high dollar items, and are, I believe, increasing in value year by year, as is generally always the case with discontinued models.

There is a thread from a few years ago, wherein a knowledgeable member listed all the RE P/Ns needed to do a 500 EFI export conversion "the hard way".  I participated in the thread, but I don't recall the thread title.  This would have been around 2021 or thereabouts.

The blanking plate is the most difficult piece of the puzzle, at this point.  I'm thinking the better solution might  be to modify an IB Bullet tank to mount on my C5, and then sell the EFI tank, which would be another net financial gain.

Most of our members seem to be well heeled westerners, who don't even consider something as pedestrian as saving a few dollars, or selling their unused parts for cash.  Apparently most folks who reported doing the conversion forked over the $400 or so that Hitchcocks was charging for their conversion kit, put their takeout parts into a box on a high shelf, and end of story.  Carb. conversions "the hard way" was apparently quite a bit more common in India, where spares for, and knowledge of, the older model RE 500s is more readily available.

I find it pretty interesting to find the old threads, here on the forum, from the days when EFI first showed up in REs, and reading some of the passionate anti-EFI comments that some folks were making.

I've managed to get a hold of all the parts needed for the "hard way " blanking plate included I have a buddy in India who can go to all the part stores as long as i provide him with a part number or at the very least a reference picture of the part I'm looking for. So im fortunate in that. I'm probably not going to sell the EFI parts just keep them for If and when i want to sell the bike and give the buyer the option of an EFI or Carbed bike.

I agree I'm not a fan of having an ECU where it pretty much all of its other functions aside from ignition timing and generating spark is pretty much blanked. I'd rather go the TCI and flywheel route. I'm not anti EFI by any means i've ridden plenty of well thought out EFI designed bikes where high precision is the name of the game in the engineering of the bike. Personally i think of the bullets and c5's as a hearty, robust, easy to work on machine that calls back to a time when motorcycles where made for people to upkeep themselves with a little elbow grease and know how. Not sure about where you guys are at in the world but around my parts if you're in the middle of a road trip and the fuel pump decides to quit, or the ECU throws an error because of some sensor not reading what its supposed to read, you're pretty much dead in the water and tow trucks or vans aren't common here. So I like the idea of carbs, gravity fed fuel system, and cables for the clutch and throttle none of that hydraulic clutch, ride by wire stuff.  (it has its time and place) Worst case is I bring a spare TCI, Coils, spark plugs, and petcock which wouldn't cost half as much as an ECU and all its related sensors and fuel pump.

At the end of the day its a personal thing I just feel more at ease that in a pinch I can cobble something together and get home.

Also as a sidenote my c5 doesnt have an o2 sensor i've looked high and low and there is none. no sidestand switch, no o2 sensor. From what I can see it only has a TPS, MAP, CHT , and a neutral switch. It really seems like they designed this bike to run on a carb and just slapped on some rudimentary EFI system to get it into the international market which i like. I've had many friends on their BMWs, Ducatis, FI harleys, etc have injector failures or fuel pump failures and ended up getting stuck in the middle of nowhere for 12 hours before help arrives.

[Monkee]

Forgive me, but I am not being rude. I just can't see what the point of all this is.

I can just about see why you might prefer a carb, but why go through all the pain of fitting a TCI when the existing ECU already makes perfectly good sparks?

Personally I wouldn't dream of changing a good EFI to a carb, because EFI works better. The fact that carbs cannot deliver sufficiently precise mixture control says it all.

No offense taken. Honestly the point is peace of mind for myself. I'm not chasing utmost performance or fuel milage, the EFI system works well enough as it is but i've just had too many personal experiences where EFI systems decide to take a shit at the worst possible time and no one but the dealership could sort them out. Or at least are authorized to do so. When i think of the bullets and classics I dont think high precision, cutting edge engineering, Performance, I think of a machine that isn't perfect but is robust and will take a licking and keep ticking. I try to avoid unnecessary complexity in operation where possible which in this case in my opinion is the EFI system. Its much simpler to trouble shoot a single carb, single cylinder motorcycle than one that has all these sensors albiet not very many sensors. On top of that access to parts to repair a carb or to get it tuned properly is so much more accessible at least for me. If i wanted to run pod filters, or a free flowing exhaust i wouldn't have to get a piggyback ECU or go to a dyno to get it to run relatively well.

thats just my two cents I'm in no way saying EFI in general is evil and that carbs are the only way a motorcycle should rely on for fuel delivery. Its just peace of mind on my end.

[SteveThackery]

I'm astonished by these stories of EFI failures. Are they actually real? Or are they stuff a mate said, or something you read on the Internet?

I've been riding for 50 years, and driving cars 48 years. I have literally never had a bike's electronics fail on me, and I've only had one electronic module fail in a car, and that was a good 35 years ago.*

They are extremely reliable, to the point where I don't worry in the slightest about them failing and leaving me stranded. If it happened, it would be pretty close to a once-in-a-lifetime event.

Oh, I've just remembered: a couple of years ago I had a reg-rec fail on a 40-year-old Yamaha - that had a carb, of course.

*I do appreciate that electronics were brought in part way through my 51 years.