[RiggsyB]

Right... Reading some stuff on Sigma Performances website yesterday (and remembering back to an article in one mag a couple of years back about their 853R), has got me thinking about saivng up for an 853 conversion for my 748SP...

BUT... I've got several questions... First and foremost, is cost... Bearing in mind, my mate's got his own 955SP engine apart at the moment (he's an engineer for a Ferrari specialist, and is pretty good with Italian engines), I'm keen to save on as much labour as possible, and do the work myself (with my mates help)... OK, I know stuff like mapping would then have to be done by a specialist, but the actual engine assembly can be done at home easily enough I reckon... So, how much would the parts (and the setting up after engine reinstalled) cost? I understand it's just a case of new barrels and pistons... Is that true? Or what else is needed? And is it perhaps worth having the heads ported whilst the engine is apart, or not worth the hassle for any extra dosh?

Next main question is that is the 853 modification reversible? Ie. if I want to revert the back to 748 spec for sale, and keep the 853 pistons and barrels, is that easily done without the engine being irreversibly modified?

Next is is it worth it? Or would I be better off swapping my (VERY good condition) 1997 748SP for a similar 916SP or 996SPS for £1500 to £2000 on top of trade in for my 748? Or will I find the 853 a much sweeter bike (I kinda like the revvy nature of my 748, but the fact it still has a lot more grunt than a Jap 600)...

And Finally, whilst I realise horsepower isn't everything, I read that Sigma Performance's 853R (standard engine apart from barrels, pistons and minor porting work as I understand it) makes 120bhp at the back tyre... Which puts it about 3bhp off a 996SPS, but with (in my opinion) a much sweeter power curve (I like a few revs)... So what kind of power would I expect from my 748SP??? 110 to 112bhp at the back tyre maybe?

Come on here... I need advice as to what to work towards... I love the bike, don't realy wanna sell it, but would love to make it quicker without losing its character...