Mr Kay Posted December 22, 2008 Share Posted December 22, 2008 Hi guys, I've got an 1100i motor that will go in my old Le Mans. I'm going to twin plug the heads and have Raceco port and flow them and I'll run a custom ignition system. I've done away with the injection gubbins as I want to run good old carbs. Does anyone have experience of either Mikuni HSRs or Keihin FCRs? I can get an FCR kit especially for the Sport 1100 which will have appropriate jets as a baseline for further tuning or I can buy individual HSRs and start from scratch. The advantage I can see with the Mikunis is that they do a 45mm bore which may suit the free breathing heads better. Does anyone have any personal experiences or recommendations? Thanks in advance Link to comment Share on other sites More sharing options...
Guzzirider Posted December 22, 2008 Share Posted December 22, 2008 Last thing I heard was that Amadeo at Raceco had stopped working on Guzzis and only worked on kits cars now with Ford motors. Have you spoke to him recently? Is he back doing Guzzis again? He would be the best guy to answer your query re carbs. I think Pete Hindley who raced an 1100 Sport at the Manx GP a couple of years back used Mikunis. Good luck with your project Guy Link to comment Share on other sites More sharing options...
Mr Kay Posted December 22, 2008 Author Share Posted December 22, 2008 Last thing I heard was that Amadeo at Raceco had stopped working on Guzzis and only worked on kits cars now with Ford motors. Have you spoke to him recently? Is he back doing Guzzis again? He would be the best guy to answer your query re carbs. I think Pete Hindley who raced an 1100 Sport at the Manx GP a couple of years back used Mikunis. Good luck with your project Guy Thanks Guy, As you say, Amadeo is mainly concentrating on four wheeled contraptions but he'll still carry out work on Guzzis. He hasn't been particularly forthcoming with advice with regards to carbs , hence the question here. Alex Link to comment Share on other sites More sharing options...
1100sport Posted December 22, 2008 Share Posted December 22, 2008 For sure the easy route would be to go with Keihin FCR 41 as there already exists a Kit for the 1100 Sport carb. The kit is perfectly tuned and the FCR gives superb throttle response and performance. I have also looked at the Mikuni HSR (typically the 42 looks good on paper for the 1100 2v) and should give very good result as well (they are designed for big HD V2 engine). From a technical POV, the HSR and FCR are pretty similar too altough the FCR are more "race proven" than the HSR. In either case, you'll have to find a solution for the ignition but there are a some options out there. Mathieu Link to comment Share on other sites More sharing options...
jcbooghs Posted December 22, 2008 Share Posted December 22, 2008 As pictures tell, I notice FCR's on Mr Pete Hindley 's bike! Maybe he raced Mikuni's as well, don't know. I have swapped my Dell Orto's to Mikuni TMR about 10 years ago. BIG difference! A true improvement. Much smoother, much shorter, much better. I've tried some Keihin FCR 41 as well. Very comparable. But in those day's the Keihin's weren't available with choke. And as I was still riding the streets those days I wanted some choke. In that case there wasn't much to choose from. There were also those huge and fat RS carbs. But they just spilled fuel, the slides shattered louder than the engine. I wasn't very charmed with that. So I went for the Mikuni TMR 40. That newer roller beared flat slide carb is a much better choice than the HSR. They do exist now in 41 too. Some info on the net http://www.supermoto-racing.de/content/ver...mikuni_tmr.html http://www.mikuni-topham.de/ http://www.allensperformance.co.uk/ Link to comment Share on other sites More sharing options...
Mr Kay Posted December 22, 2008 Author Share Posted December 22, 2008 Thanks guys, I've managed to find a price for the FCRs here in the UK - £940 the pair (approx 1100euro) which is a little beyond my budget. I can stretch to £500ish for a pair of HSRs though. Shame really, I love the idea of the roller bearing slide. One of the guys on here is running HSR42s on his bike but suggested that it'd easily run 45s, I'm tempted to try the bigger ones, especially with gas-flowed heads. The old 850 mid-valve engines could apparently happily run 40s (crude dellortos at that) so it should be ok. Ignition won't be a problem, my father is developing a programmable system that will run from the existing camshaft pickup. I'd have to do some messing about in that area anyway to get the most from twin plugged heads. Alex Link to comment Share on other sites More sharing options...
Murray Posted December 22, 2008 Share Posted December 22, 2008 The FCR's are brillant IMO I've never missed the choke ethier Mukuni's I have heard can be a bit tricky to setup but thats more rumour and innuendo than direct experince. Link to comment Share on other sites More sharing options...
1100sport Posted December 22, 2008 Share Posted December 22, 2008 Thanks for the info, very helpful. I have a pair of Dell Orto 41 (instead of Phm40) and that was already an improvement over stock. But I like the idea of moving to flat side carbs. Any recommendation regarding jetting for the TMR 41s? How did you set your TMR 40? Did you mount them on the oem rubber? Thanks for your feedback! Mathieu As pictures tell, I notice FCR's on Mr Pete Hindley 's bike! Maybe he raced Mikuni's as well, don't know.I have swapped my Dell Orto's to Mikuni TMR about 10 years ago. BIG difference! A true improvement. Much smoother, much shorter, much better. I've tried some Keihin FCR 41 as well. Very comparable. But in those day's the Keihin's weren't available with choke. And as I was still riding the streets those days I wanted some choke. In that case there wasn't much to choose from. There were also those huge and fat RS carbs. But they just spilled fuel, the slides shattered louder than the engine. I wasn't very charmed with that. So I went for the Mikuni TMR 40. That newer roller beared flat slide carb is a much better choice than the HSR. They do exist now in 41 too. Link to comment Share on other sites More sharing options...
rocker59 Posted December 23, 2008 Share Posted December 23, 2008 I'm running the Keihin FCR41s on my '96 carb Sport 1100. Bought 'em in a kit from SUDCO here in the USA. The kit was good. Really all I had to do was richen up the idle mixture and it runs pretty darned good. The cables weren't quite the right lengths, but they worked out. The switch to the FCRs instantly changed the bike. Better throttle response, lighter throttle pull, better fuel economy. No chokes, but I've not really missed 'em... Link to comment Share on other sites More sharing options...
jcbooghs Posted December 23, 2008 Share Posted December 23, 2008 How did you set your TMR 40? Did you mount them on the oem rubber? I would have screw it open to see what jetting is used. When I got the carbs, standard jetting was just quite allright. If you are that far, I will check and let you know. The carbs are indeed mounted on the OEM (Le Mans 1000 - Sport 1100) rubbers. Are you going to ride it with the airbox? Because I don't know if they have a fitting solution for this. The Keihin FCR's do have. About the choke: I think the latest FCR's do have choke too now. But as been told here none is missing them. As a matter of fact I have eliminated mine too (but I never ride the bike on a cold morning). An idea: if you want BIG why don't go looking for a set of 48mm Honda Firestorm carbs? Just a wild guess, I have no idea if it should work. Link to comment Share on other sites More sharing options...
Mr Kay Posted December 23, 2008 Author Share Posted December 23, 2008 Thanks again guys! I've done a little research and discovered that apparently the HSRs do have the roller bearing slides. I think I'll give Allens Performance a bell and see what they reckon. An idea: if you want BIG why don't go looking for a set of 48mm Honda Firestorm carbs? Just a wild guess, I have no idea if it should work. Downdraft carbs I'm afraid. Link to comment Share on other sites More sharing options...
Murray Posted December 23, 2008 Share Posted December 23, 2008 The orginal rubbers I found were a bit flimsy for supporting a carb without the aid of the airbox at the other end. Went down to the local serious auto store and order a half meter length of fuel delivery hose of the right diameter. From memory it was listed as about 1mm smaller than the actual carb throat but a bit of hot water got it sorted. The hose is rienforced with copper wire to give it a bit more strength can be cut with a stanley knife with a new blade without too much of a drama. From the local hardware store got a four stainless hose clamps (much wider than stock) total cost $20-25 australian with enough for a couple of bikes and maybe a mistake or two while cutting and the carbs don't get that droopy look anymore. Link to comment Share on other sites More sharing options...
jcbooghs Posted December 23, 2008 Share Posted December 23, 2008 Can you post a pic of that solution, murray? I don't think about a droopy look with the OEM rubbers. Link to comment Share on other sites More sharing options...
Skeeve Posted December 24, 2008 Share Posted December 24, 2008 An idea: if you want BIG why don't go looking for a set of 48mm Honda Firestorm carbs? Just a wild guess, I have no idea if it should work. Downdraft; not gonna work. Link to comment Share on other sites More sharing options...
bigdog Posted December 25, 2008 Share Posted December 25, 2008 Ignitech might be the go for the ignition. They produce an ignition that will work from the original Hall effect sensor. Link to comment Share on other sites More sharing options...
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