I have a 2002 748E looking to make 853. Are the testastretta headed stud spacings the same as the earlier 748/916 crank cases?
I mean the later 748 drop cam head with the 5bolt side covers. Is that not called testastretta? Anyhow not deviating, I want to use this head with 916 barrels. cheers
Chris the MY02 heads were called Testa Bassa (Dropped Head), I think the barrels are the same. Testasretta (Narrow head) is the 996R/998/999 and onwards engine The final part number for cylinder and matched piston is shown for all versions MY02 back to 1995 in the parts data, suggests they are all interchangeable
Chris, I converted my 2002 748 into an 853. I used 916 cylinders from a monster s4 but any 916 cylinders will do,. The only difference is where the little locating dowel sticking out of the case is on early 916. If you use these cylinders you need to drill a hole for the dowel. Make sure you get the right head gaskets. What sort of pistons are you using? You need to check that, if you are using domed high comp pistons, that they don't touch the head at TDC. My FBF Wiseco pistons did so I had to grind out a bit to give clearance. Make sure that you check squish clearance and change base gaskets to get it to 1.0mm you shouldn't use your 748 Eprom as it will run seriously lean. Get a special Eprom for the job from Brad The Bike Boy and he will also help you with with his suggested cam timing. Good luck. It's a worthwhile exercise. It's possible to do the change with engine in the frame but a lot easier if you pull the engine. If you do pull the engine expect some drama around the swing arm pivot bolt. You probably won't shift it without the special (or manufactured) drift tool. If the engine is out it's easier to clean and repaint if necessary.
JHP also do chips for the 853, I gave John the spec of the engine and exhaust and he burnt one from his library, it works perfectly. That's if you don't go down the route of having it mapped on a dyno. Steve
Thanks Martin I will be using used 916 barrels and pistons and following @zxrjohn14 build posted in forum as 748/853 Build I’ll be machining the barrels, lightening the pistons and using 2 adjustable belt tensioners. Big thumbs up to zxrjohn, I think it’s a great post. Thanks Birdie for the JHP heads up on eprom. I intend to do it as a budget conversion and as everything else is standard an off the shelf eprom will be perfect. Thanks everybody.
