Forum

[Cranky]

Ask away John,--what ever you want to know.

[windmill john]

I think I’ll be a viewer Cranky, electrics are a dark art, the devils spawn to me

[Adrian]

So when you have (apparently) unlimited access to dirt cheap parts at least you can experiment to your heart's content, though I do wonder if your VM32-33 is the genuine article, those clever Chinese seem to knocking out er... replicas of all sorts of carbs, VM Mikunis and Dell'Ortos included. Does Lazada ship to the UK?

I had a (much more expensive and genuine) VM32-33 on a tuned 350 BSA B40 a few years ago, great carb, can't remember the settings, unfortunately.

You seem to be getting very good results flying by the seat of your pants, will you be marketing your own kits soon?

An AC unit will need 3 phase supply through a rectifier or a Charge coil in the flywheel magnets and the RE does not have this.

Nowadays they don't, but some home market 350 models in the first half of the naughties had CDI ignition using a modified version of their standard copy of the old Lucas alternator stator, with one of the general charging coils replaced by a capacItor charging coil and a 5-pin CDI that looks an awful lot like the AC CDI boxes the Chinese bikes are still using.

Keep us posted...

A.

[Cranky]

Valid point on the VM 32 Adrian and one that had crossed my mind too but looking at it it seems well cast and is identical to ' A real one' so much so that if it is not a real one it does'nt matter. It does not have Mikuni written on it. It is nicely shot blasted and came in a lovely plastic bag which I shall use again for something else later.

The slide by the way is solid brass and chromed. Its not a cheap carb.

If an item as good as this can be made in Taiwan and sold and shipped for 20 quid ( less actually) then so should other manufacturer. It has some lovely machining and obviously not made by barefoot children in a mud hut. Not to rabble on but it could well be a Mikuni purposely made without the logo to sell more carbs at a cheaper price without lowering there top brand.

Im pretty sure Lazada will not ship to Uk but you could look at it on Lazada web site, they allow you a close up zoom view of all their items and I like the COD.

Most bigger bikes use DC. This means that the 12 volt is transformed up to a much higher voltage before it can be used. This is why it is usually heavier. An easy test "care of the internet is' if the head lamps come on when you start the motor it is AC . So a C5 is DC and thats good because it is sooo simple to wire up . Trigger -coil- DC supply from kill -Earth.

If I were to break down here any motor bike shop would have some parts for this now.

[Rattlebattle]

Fascinating...a bit beyond me to actually do, but I get the gist of it. A couple of things: with the kit conversion you are right, the MIL is permanently lit because there are several ( fuelling-related) sensors that are disconnected, though the injector itself “fires” in the sense that it receives a signal from the ECU, but is disconnected. One can either use the MIL as an indication that the ignition is on or, as I did eventually, disconnect the MIL bulb. One day I might bin the MIL and fit an ammeter in the hole. My second comment is a question: I don’t understand why the ignition timing should be affected by removing the EFI parts of the system. AFAIK the RE EFI system (Euro III at least) is pretty crude. Rather like, say, a Boyer ignition system is the advance curve not just based on engine revs? These engines are in a low state of tune and don’t rev highly, so I’m not sure that harm will occur just by removing the fuel injection side. The only issue with ignition timing I have come across ( rare ) is that some were made with a sloppy keyway on the crankshaft affecting the baseline of the timing. Certainly in my experience my engine does not pink and is a bit quicker at the top end, though keeping the original twist grip means that the throttle won’t fully open in a single twist as before. I take your point about easy spares, but almost all the issues re the EFI have been on the fuelling side and even then the ECU seems to be pretty reliable. That said if a cheap kit were produced to replicate what you have done and I hadn’t already done mine I’d probably opt for the “complete” conversion. The original one, having a new rotor and ECU was expensive, dearer than a Power Commander. This is probably why the current “bodge” system was introduced.

[windmill john]

I think in many systems the TPS does affect the ignition advance. So removing the EFI and disconnecting the TPS would affect ignition.


John

[Rattlebattle]

If the TPS does affect the ignition (and I can see how it might) presumably the effect is negligible. In the fifties when bikes often had manual advance/retard on the magneto, riders often only retarded the ignition to start the engine or to lug up hill. Effectively the timing was fixed on full advance for most of the time. That’s certainly how I ran my manual mag bikes.
I would have thought that, at best, any change to the ignition curve by the TPS input would be limited by comparison to that of the crankshaft position sensor, from which engine revs are determined. If disconnecting the TPS were to have a big impact the conversion wouldn’t be as successful as it has been. Apart from the crankshaft position sensor the only other one retained is engine temperature. Someone on another forum had a possible problem with his so I disconnected mine and went for a ride - no effect on the usual running whatever....

[windmill john]

If disconnecting the TPS were to have a big impact the conversion wouldn’t be as successful as it has been.

Good point... I wonder if the TPS only has an immediate effect to increase advance if the throttle is whipped open Suddenly...
Out of my depth so it’s only ideas.

[Cranky]

If the MIL light is on isnt that an MOT failure --it is on cars. If all the sensors are in a non input mode exept the only one being the exhaust temp sensor and CPS it is understandable that with input from the CPS the ECU will be very upset indeed and retard. As no mapping or any further information on this is available it is guess work as to what the ECU will do but im pretty sure that if the mil is on it will be full retard.

The temp sensor is actually an oil temp sensor and is in the oil flow to the head. I shall be putting a oil pressure light sw in its place (ordered) and use the mil as an oil pressure light.

Im still running retarded at the moment---the bike I mean not me. I have transferred a TDC onto the crank gear on the left hand side so as to use a strobe and fathom out what is happening with various sizes of Capacitors.

It may be that I might have to adjust (cut) the rotor tab a bit and mechanically adjust. At idle im a just a tad behind TDC.

So with a rotor of 118 MM that just about 1mm per degree. Ive nothing else to do,-- I hate Golf.

[windmill john]

So.... as the TPS is a potentiometer, when it is removed during a carb conversion, the bike must be at either zero or full according to the missing potentiometer. But... is that full advance or rest; can’t imagine it is full retard.

So... again.... how do owners know if after the conversion what they’re running. I assume performance compared to pre tear out will show.