Forum

[Thack]

Rattlebattle writes: "To summarise, if I have understood correctly, it seems to me that when running in and/or using a standard spec bike for short runs or just cruising at 50-55mph the best thing to cure sooty plugs is to use a hotter one eg BPR5ES. Those who work the engine harder and longer would seem to be better off with the standard colder plug."



I would say that is an excellent summary, yes. Spot on.

[Thack]

Rattlebattle writes: " If one intends to tune the engine and/or fit less restrictive air filters and exhausts then either PCV (or EJK) would appear to be necessary or, if preferred, the cheaper carb conversion."



Again, spot on, yes.



Rattlebattle writes: "I get the impression that the PCV alone may not suffice if perfection is sought throughout the Rev range. I intend fitting the carb conversion tomorrow. I'll report back in due course."



If you want perfection throughout the rev range then the carb conversion is the very last thing you should fit. All carbs are imperfect, and the Amal Concentric Mk1 is probably the most imperfect motorcycle carburettor ever made.



On the contrary, the ONLY way to approach perfection is to use a fuel injection system, modified if necessary by a PC-V if you've altered the intake or exhaust system.

[Thack]

Tim NZ: I apologise because I realise my tone in my reply to you was rather rude. I still disagree with what you said, though, but I'll explain why in a more respectful tone.



You wrote: "As for the Idle speed adjustment; technically it is not an Idle Adjustment, but rather it is an air-bypass bleed; it offset the effects of the 'Idle' fuel injection settings..."



The manual you quote makes it clear that the air bypass screw is the idle adjustment. "Turn the screw CLOCKWISE (in) to DECREASE the idle speed. Turn the screw ANTICLOCKWISE (out) to increase the idle speed." They emphasise that it is not a throttle stop screw because you turn it the other way - anticlockwise = faster, whereas on a throttle-stop screw anticlockwise = slower. But clearly it IS the idle speed adjustment.



You wrote: "...it offset the effects of the 'Idle' fuel injection settings."



That's the bit that makes no sense. What "effects"? What "fuel injection settings"? It doesn't offset anything - it is simply one of the three settings, along with the throttle stop and the TPI adjustment.



Finally, you said that if you move the throttle stop screw: "...you will need to get the whole FI system recalibrated."



I think this is misleading. If you accidentally turn the throttle stop screw, all you need to do is put it back where it was, which you can do by looking at the paint seal on it. The factory software makes it easy, but the main purpose of the screw is to stop the throttle plate jamming in the throttle body. If you've lost the calibration and can't get access to the software, a good start is to back it right off and then screw it in until it just touches the lever, and then another 3/4 turn. If you find you can't get the idle speed into a sensible range with the bypass screw, they you can move the throttle stop screw slightly one way or the other. Just make sure it always holds the throttle plate open slightly. Once you've done that you then adjust the TPS with a voltmeter.



Of course, I don't advocate moving the throttle stop screw. I'm just saying that if you do so accidentally, it's not the end of the world and you can sort it out without access to the factory software. That is there primarily to speed up the production process.

Again, Tim, I'm sorry for my curt response earlier - I need to take some lessons at my local charm school.

[Rattlebattle]

Well, ok yes, using a concentric won't get perfect fuelling. My choice would be a monobloc, not least because you can easily change the pilot jet on it and they are better made. All I want is acceptable fuelling that I can alter easily if I change the exhaust or whatever. This should be achievable as indeed it used to be on n British singles. It is a cheaper option than a PCV and it appears that the idle on the EFI system requires more than that fully to sort out - wide band O2 sensors and other stuff that has been mentioned. I don't have the knowledge, inclination or kit to tune the EFI on the RE. Hence for me the carb conversion seems the best and most cost-effective way to go. In my experience the concentric is ok on a single, less so on a twin carb setup. I'll give it a try.

[jefrs]

Rattle battle - re plugs - absolutely right, got it up in one. If actually racing where the motor is basically used at red-line revs (full chat) all the time, you may well want a colder plug than a NGK "6" - but we don't do that to road bikes do we.



These motors differ a lot in use and from one motor to the next, I'd go with the suck it and see - if the plug gets filthy when there is nothing wrong with the engine, try a hotter one but if it is getting burnt then go colder.

If the plug gets too hot it can glow and produce all sorts of nasty things like holes in pistons, you'd have to use an extremely hot plug for that and hopefully strange pinking noises would alert you before damage. I did that once to a Bantam because being a 16yo idiot I used the plug the shop sold me, not only the wrong heat but entirely the wrong plug.

[apparently lucky eddie]

WTF does it all mean? EFI, ECU, open loops, closed loops, PCV, AFR, O2 sensors, as I said, WTF?
Thank the heavens for a nice simple, efficient, idiot proof Amal Monoblock!

[Thack]

apparently lucky eddie writes: "WTF does it all mean?"



Well, it's funny you should ask... (takes deep breath).



Naaah, only joking. Life's far too short!

[papasmurf]

apparently lucky eddie, list of acronyms:- http://www.ukautotalk.com/abbreviations.htm

[ric]

[Tim NZ]

The large brass screw on the top of the injector body IS NOT an idle screw,


Yes, it effects the idle speed; in precisely the same matter as the Pilot Air screw on a carb.


Or having a perished and cracked manifold rubber...


Or a warped carb mounting flange...




And in a further related step, in the same manners on the Domestic Bullets as the AUXILIARY air bleed screw on the induction manifold: It effects the low speed air/fuel ratio by permitting more or less air into the system.




Do not have access to a Plug-in EFI analysis tool?

DO NOT FUDGE with the the throttle stop screw! The system has a 'Dumb' Throttle position indicator to base-line all other settings to/from.




Amal carbs are seriously outdated inferior junk are they?


So too are push-rod operated Overhead-valve, single-cylinder, Long-stoke, drum braked, swinging arm, telescopic forked motorcycles...




Most people on this forum can cope with carb tuning? Where as it would seem like there is only a couple or three who understand the workings of the seriously outdated fuel injection system that RE utilise. It is spec'd low, bought on the cheap, running with low quality sensors/senders whose 'specs' are all over the place.


As a result it is no wonder that the settings seem to be all over the place...