Hi all. I've had my 2002 748 for about 18 months and have put 10,000 km on it. It's the best bike I've ever owned but down on grunt compared to my "old" 999. So I've decided, after much research to go the 748 route rather than a 916 conversion as, at this stage I don't want to split the motor to replace the crank. It ha a 50mm half termi system already with the corresponding EPROM chip in the ECU. Does anyone have experience or knowledge as to if any changes need to be made in this area or will the extra 105cc engine run just fine with this setup? Thanks in advance
The 853 conversion has been popular for several forumites , me included. My 853 based around a 748RS makes 133 hp and a smidge under 70 lbsft torque. EVR in Italy offer 2 complete conversion kits for standard compression and high compression engines which comes with an eprom to suit. I can highly recommend this route. Shame you are in Perth, WA as I will be selling my 853 engine. Good luck. Andy
I notice your in Ozz so I might not be of any use to you, when I upgraded to the 853 I got in touch with JHP (Ducati Coventry) and gave John Hacket all the info regarding engine build and exhaust and he made me a chip to suit from his library of information from past builds. The new chip was about £40 six years ago and it was and still is faultless, the bike runs perfectly with no flat-spots or hesitation right through the rev range. It will never be a 996 or a 999 but is noticeably more punchy at low revs than the original 748. Steve
I ran my 748/853 on the 50mm half system. works a treat. I found the 50mm headers a tad to big. You'll need a different eprom to suit, but they're easy to come by. The EVR kits are very good. Pistal also do drop in pistons but you'll need to get your cylinders bored/plated. Go for weighted pistons, made for the job to prevent the need for balancing. Dropping 916 pistons in is teh hard way. Have a look on bikeboy.org for further info..... load of interesting reading on there.
I'm currently having my 748 converted to 853. Pistal pistons with barrels bored out then re-plated. 50mm full system as well which will work well with the increased bore size. Currently waiting on the EPROM from JHP ... Not the quickest !!! .... can't wait to get it back while the good weather lasts.
If you don't mind me asking, how much is the EPROM from JHP? I also think the 50mm pipes are a tad big too. My 748 has terrible mid range pull
IIRC about £60 when I asked for one for my 996. Rich at Luigi Moto was cheaper and turned it round in about a week.
Yep. I saw negligible top end gains with 50mm headers, but the 45/50 gave much better mid range. I ran T1 cams, flowed heads with oversize valves and the system coped just fine. For my mind, the 50mm headers aren't needed until you're at about 125bhp+ unless you're chasing peak numbers. Personally, I like me mid range
Don't forget I'm going up to a 853 bore which with the revised chip will work well. Going to a 52mm bore would cause a loss in midrange.
Go and speak to Justin at protwin in wangara he will be able to give you the answers and will be able to do whatever you need.
