I have just had my engine rebuilt. Along with careful rebuild and balanced crank it has a lightened flywheel, JE 11.5 to 1 pistons (standard 904cc), SS900ie cams and reworked ports. I will be fitting FCR39 on standard (long) inlets. I know I will be sacrificing some HP and max revs with a ‘Paired’ set up compared to separate FCRs but cost and the fact that this is not a track bike mean that this is the route I’ll go down. So the question is... Has anyone gone a similar route and if so do you have a set of baseline jetting/ needle settingsfor the FCRs I could work of as I will be getting the carbs stripped and cleaned before I get the bike set up on a Dyno. Hoping that the combined experience here can help me
160 main, std needle on the sixth notch, 52 pilot jet, it is usually just slightly rich on those settings but as good a base setting as you will get for your set up, Set the float height to 9mm to start with However what is in the carbs now? are they close to the above If the bike runs and you are going to the dyno why spend on jets when when the dyno engineer will change them and charge you for new ones anyway
Ey up, I have FCR 39's on my 900ss. I run hi comp pistons, open airbox and straight through cans. It goes really well using these base line settings and have done for thousands of miles- Fuel screw mixture screw 3/4 turn Slow Air Screw 1-1/2 turns Float height 9mm Main Jet 155 Main Air Jet 200 Slow Jet 60 Needle EMT Needle Clip 3rd from top Taken from this site: http://www.ducatitech.com/2v/fcr_faq.html
I've got 41s and mine and simply love them. I have heard over the years that the 39mm gives a better driveablility and you may find them a little easier to live with over the 41s, they don't have as much top end, but they have a really good torque spread. My settings are not much use to you, however, I completely agree with Sev on this one, a rolling road is the only way to get the most out of them. I look forward to hearing your progress. I will also add, that I went the banked route, like yourself and that the split carbs are a bit better, performance wise, as they sit on the shorter manifolds, which flow better. But I can tell you, that the offset against the trouble in setting them up is OK for me.
First of all thanks for the rapid replies. Have no fear, I WILL be getting the carbs set up on a rolling road. The carbs have came off a 750ss and I wanted to be sure the settings aren’t too far off before I (eventually) start the bike up and put a few miles on it before I get onto the dyno. Bike has had newly plated bores so probably looking at 500 shakedown miles before I do that. Haven’t opened the carbs up as I intend to get them refurbished by someone who knows what they are doing (I know my limits!) and I don't want to mess anything up with my own cack-handed dismantling. The engine is actually in a Bimota DB2 and, engine or rest of bike, I’m finding the rebuild is a good way to use up time and ££££ during Covid restriction era!! Not quite Richi Sunak but its my own personal business support scheme!! I’ hoping that the old saying that “ quality is remembered long after the cost is forgotten’ will hold true! Hopefully just a couple of weeks from being able to post up some pictures of a rolling chassis with engine installed after 12 months of going in the other direction.
Slightly O/T and not wanting to panic you but do you know what Piston rings were fitted to the JE pistons? Asking because the supplied rings on my 944cc JE pistons were not compatible with the Nikasil coating in the cylinder and so caused problems.
Send them to Matt Harper @ Harper's Ultrasonic +44(0)775 200 8698 He knows just about all you ewant to know about FCR's.
I spoke to him yesterday. He certainly seems to know more than enough re the FCR’s workings. Its another expense but heh hoh....only money!! WIll strip off my donor bike this weekend.
Indeed and, IME JE 94mm (944cc) 'Ducati specific' pistons are (or were) supplied with chrome rings. Non-chrome rings can easily can be sourced but you certainly want to be aware what's in there.
I found out when I had my MkII.....not on my bike, but by the number of 850s I had to repair when people had got it wrong. Two engines had seized absolutely solid where everything had welded together in the bores. Sometimes it was possible to get away with chrome rings, but it would mean keeping the revs very low and not running for too long; with more than regular oil changes too.
The piston kit was specific to 900SS standard bore 904cc. so hopefully they should be compatible with Nikasil. Maybe the 944 are used on other non Nikasil engines and hence the issue? Have asked J&E for a response
Should have got my FCRs off to Matt Harper when I first discussed. They would be worked on by now rather than 'in the queue' My fault. Still, I'm sure the time on the rebuild will pass quickly!! A stock rebuild using stock parts is just SO much simpler than a modified 'special'. I'm not especially gifted on the mecahnics etc so putting out work where it makes sense and of course good guys are always busy. Will get there in the end!
This is the Bimota DB2 I've started from. It was missing bodywork,seat, petrol tank (15 months to find one!) throttle, some electrics etc etc. Felt I just had to save it from the breakers... . heart ruling head! Bim parts are rare and expensive so its taken time to get the bits together ( from other Bimota owners a (very) few specialist dealers and getting some parts remanufactured) lots of corrosion and cosmetic issues. Suspension leaking back and front!! broken cush drive bolts, and lots of other issues its been a nut and bolt resto with several upgrades along the way...... Marvic Penta 1 wheels and refurbed cast iron Brembos (Oh and rear disc is unique of course to Bimota!) and at least the engine is back with me after a full rebuild (J&E pistons, SS900ie cames, headwork, balanced crank etc) and I think looks better than new. Thank you Richard and Chris at Louigi Moto. My inspiration is a one off special built by the Japanese Bimota Importer 'Moto Corse' If I get anywhere near this with the final build It will be my keeper until I hang up my biking boots. Onwards and upwards
Good luck with the rebuild! As a kid I used to drool over Bimotas in the Cranleigh showroom (early 80’s)
Galleria cranleigh! Used to get lots of their bikes repainted by an outfit “Kinetic Art’. Some pretty way out colour schemes!!
