boxer cup single spark/twin spark?

[mart123]

hi all, i have a 2002 boxer cup, single spark, is the twin spark much different. It is worth looking to upgrade

[horse27]

I have a 52 plate single spark as well ...

As far as I know the twin spark was just for emissions purposes - cleaner burn, etc. No performance gain.

Also, I am told the single spark is less fussy when it comes to dumping the cat and fitting a K&N.

I.e. the twin spark runs very lean - dumping the cat makes it leaner - as does fitting free-er flowing filter, etc ... so you may need to get a power commander.

Er, and the single has less plugs to replace at service time

Cheers.

[andrew s]

Hi Mart,

No not worth changing, the twin spark has obviously 2 more plugs and different stickers on the bellypan and different handle bar grips and thats about it. No difference in performance.

Andrew

[Steptoe]

Twin spark main cap coils fail with monotonous regularity = £55 a side to replace.

[madman]

fail with monotonous regularity

Can't be that bad as mine have been fine so far.

[PBBoxer]

No pwer difference between twin spark and single spark. It was done for emissions as said, according to a couple of BMW people.

[Ruffy]

My twin spark coils have gone once on both sides so that's not a good recomendation is it?

[oyster]

I met a chap with a R100S who converted to twin plug. He couldnt stop praising the improvement, much better low down grunt. I reflected on this to the race bike tuner in Sittingborne with a view to doubling the sparks on an R1100S. He believed that the difference in engine design over the intervening 30 years absorbed any further gain. Squish bands, valve location and timing, porting et al. He went on to suggest that degreeing in the cams probably wasnt worth the effort, the gain was so small. I have read since that if anyone is thinking of doing that, they should use well run cam chains, i.e. 50k miles, to ensure they have stretched all they are going to. The BCR twin sparks are for emmission control. And expensive plug cap coils.