I'm interested. Please explain how the bike knows it has Crane sparks and how the Crane brand allows you to have a more exact spark timing than another brand when, as far as I know, you can set the transducer that triggers the spark anywhere you choose, exact or otherwise?

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Try doing this to yer fueller...........

Hmmm 3, do I detect the faintesy whiff of sarcasm / cynicism?

According to the printed instuction sheet for my Crane, it delivers a single spark (so eliminating the wasted spark on the exhaust stroke) and also allows you to alter the advance curve and rev limit. Naturally it'll only be as good as the man who sets the initial timing, as with any system...
Must be an increased advantage if it's used on an earlier HD with points and mechanical advance though.
It was the 'single fire' bit that was important to me... I can now get sensible readings from my Stack tacho...

So, the 'Craned' engine has no spurious sparks, a variable rev limit and an adjustable even programmable advance curve and clearly is a much happier engine all round.

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'98 M2 Razorback, it's a keeper.

Indeed you detect a certain scarcasm and cynicism. If you could explain to me why eliminating the spark from the exhaust stroke of a 4 cycle engine makes any diffrence whatsover to what happens in the cylinder 360 crankshaft degrees later on the compression stroke I'd apprecate that too please. (I guess there's a somewhat debatable argument about coil soak, dwell angle and that kind of stuff). Does the motor really care as long it gets a spark "x" degrees BTDC on its compression stroke?

I can understand the reasons why a programmable advance curve module might be better able to fit to the characteristics of an engine for sure. (Whether it is actually enough to make any significant difference on a low revving long stroke 2 valve motor rated at about 72 horse power per litre is moot I guess). I do have such a device myself.

The other stuff I simply can't see any logical advantge for outside of bar room racing. It makes the world go round, not everyone is as grumpy as I am.

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Try doing this to yer fueller...........

Well... Crane say (in writing) that ..."Single Fire operation increases engine power at high RPM, improves starting, and reduces the likelihood of backfiring at low RPM".
Presumably they have to be able to substantiate those claims.
The 'engine power' and 'ease of starting' may not be readily noticeable but I can see their point on the backfire bit. And I agree with you over coil recovery... not really an issue on an old wheezer like this!
I fitted a Stack tacho to my M2 and it could sometimes not make up its mind whether to read half, correct or 2x RPM due to the irregular firing frequncy on the dual spark HDB ignition... I understand that HDB tachos have to be very heavily damped to cope...
Oh, and you get a nice sticker with it too......

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'98 M2 Razorback, it's a keeper.

im no tech head,and im not about to expain thngs i dont know to someone who does.

but the way i see it is, is that its not about the single fire just giving a better spark, but about how the module allows you to alter the timing adjustments and thingys

I alsofound it works wonders with the thingymajigs

so there

other single fire ignition systems are availbable - but crane (in my opinion is the one to go for) - but what do i know? - apart from my buell is quicker than yours

I agree, Crane make a fine ignition module, it seems. The one I bought a few years back now is by Dyna, badged as Screaming Beagle. It does twin/single fire too, I think there's quite a few available that do this, but I bought it primarily for the adjustable advance curve and rev limiter.

Oh, yes, everyone's Buell is quicker than mine, no debate there

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Try doing this to yer fueller...........

I thought the key point about single fire ignitions was that you had 2 coils - one for each cylinder. Otherwise, with a single coil the "other cylinder" also sees the "spare" spark.

Now if on a funny v-twin, I think one cylinder will see the spare spark ~45 degrees after TDC but the other cylinder will see the spare spark ~45 degrees before TDC. The first of these will be during an inlet stroke - and this is supposed to be a bit dodgy (as it _might_ cause some limited partial combustion) - while the second is on the exhaust stroke - no problemo.

Hence the folklore says single fire gives smoother idling - and this seems to be true in practice also, e.g if you ride 1995 carbed and 1996 EFI 'glides back to back.

I think the older crane's also allowed you to set the timing offset between the 2 cylinders so you could optimise the holeing of the rear piston but doing that is _so_ 1999...

i know its dyna, but it has the same result as my crane system did, long but worthwhile read
http://www.badweatherbikers.com/buell/m ... 1126114650



whichway?

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........have you tried turning me off & then turning me on again ?

Thanks Derek, indeed that's the received wisdom. Nothing to add to that.

Whichway? posts some very intersting info back from when Aaron ran NRHS. Aaron did a huge amount of fine work back then both confirming and myth-busting various pieces of received wisdom. It was as a result of that particular work that I decided to purchase the Dyna ignition system. It was much cheaper to buy the rebadged Screaming Eagle version though rather than the Dyna version. Same thing, different badge.

I've no axe to grind really, just taking an opportunity to be a little controversial and flush out a bit of debate. Thanks.

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Try doing this to yer fueller...........

Yeovil is not too bad a ride from Southampton, give Mayors Motorcycles a ring, they have a good dyno rolling road set up which gives live data. They appear to do work their magic on many machines and are a V twin specialist.
(Nursling, Southampton, just off M271/ M27, 1 mile and a bit before DG20, walking distance if you wanted a coffee whilst waiting)

thanks mate ......... I travel down to Tubbs for the juicy stuff, so am used to that route - like you say no big deal.

How do the Moores speed and Mayors Motorcycles dyno set ups compare, amy idea.