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Looking to buy an AAU for a 250 w/DC system
Posted: Sun Mar 08, 2026 8:56 pm
by JimF
My 250 narrow case is extremely difficult to start and is killing my knee when I try. It has no Auto Advance Unit.
A while back I purchased an AAU just for this reason, perhaps off eBay.
As I was getting ready to install it, I found a thread that indicates there are two different AAUs, one for DC "AA359" and one for AC ignition systems.
My motorcycle is running a DC ignition.
I hoped the AAU I bought was a DC one, but this unit has no markings on it whatsoever.
Does anyone have a DC AAU "AA359" they can sell me? I'm located in the US.
Thanks,
Jim
Re: Looking to buy an AAU for a 250 w/DC system
Posted: Sun Mar 08, 2026 9:11 pm
by Duccout
Hi Jim,
What about ditching it and buying an Electrex World ignition system?
Cheers,
Colin
Re: Looking to buy an AAU for a 250 w/DC system
Posted: Sun Mar 08, 2026 9:43 pm
by JimF
My knee-jerk reaction is that it’s a lot of expense given the monetary conversion, international shipping and tariff costs.
On top of that I’d incur the secondary expenses and potential for other issues converting from 6V to 12V.
If a simple AAU implementation fixes my hard starting issue, it’s a fast and potentially inexpensive solution.
I’ll keep your suggestion in mind but I will reserve considering it seriously only if faster/easier solutions don’t work.
I do appreciate the suggestion.
Jim
Re: Looking to buy an AAU for a 250 w/DC system
Posted: Mon Mar 09, 2026 7:32 am
by Bevel bob
Hi Jim , i think the Monza AAU is the one that is commonly around . My 250 M3 has one and does not kick back .
Re: Looking to buy an AAU for a 250 w/DC system
Posted: Mon Mar 09, 2026 9:03 am
by Jon Pegler
Jim,
The photo you posted of your auto advance is correct for a DC/ battery ignition.
Re: Looking to buy an AAU for a 250 w/DC system
Posted: Mon Mar 09, 2026 12:48 pm
by JimF
Thanks Jon and Bob. I will install the AAU and hopefully solve my kick-back and hard-starting issues.
Re: Looking to buy an AAU for a 250 w/DC system
Posted: Mon Mar 09, 2026 4:30 pm
by Bevel bob
Hi Jim, I set the timing up so that its about 5degrees before tdc when static . Seems to do the job. Still looking for a set of swan bars ,too old for clip ons now.
Re: Looking to buy an AAU for a 250 w/DC system
Posted: Wed Mar 18, 2026 1:00 am
by themoudie
Aye Bob,
Whilst he no longer lists swan neck bars, Barleycorn Engineering used to make swan neck bars based on the old Norton Inter bars, in stainless. I fitted a pair to the 450 and find them an improvment on the standard clip-ons. However, I would have preferred them to have another 1" (25 to 30mm) lift in them. At the time they were available in different diameters to suit different stanchion diameters.
I attach a picture of the 450 and me, not to show my mug, but to give you some idea of my 6' 2" frame perched on the 450, with pillion rearsets and the Barleycorn swan neck bars fitted.
Here is the link and see how you get on, post back here, if you would please?
Barleycorn_Engineering_possible_swan_neck_bar_supplierGood health, BillR