Current Project #2 (yes i know, hindsight is great!!) I have a Bimota DB2 fitted with a 750ss motor ( was originally a 400cc Japanese model) Although the standard DB2 uses the 900ss motor I think that the torquey 750 motor is probably a nice fit for the sweet handling DB2 chassis (also has narrower rear wheel/tyre than the 900!). It has a larger bore 2-2 exhaust but engine is otherwise standard. Re carbs I am undecided. I have a set of 40mm Mikuni TMR carb available but worried that this may be 'overcarbing' the engine plus I have no idea of the correct jetting. Has anyone had any experience of these Mikuni carbs? Most probably fitted to 900s i guess? There’s lots of comments about Keihin FCRs on Ducs but not so about Mikuni flat sides. One nice feature for a road bike (in Britain!) is that the TMRs have a choke as standard. Given the engine tune I am also considering selling the TMRs and trying to find some NOS Mikuni VCs (OE fitment) to replace them. Comments please
I have TDMR 40s on my 93' 750ss. I am still waiting on lock down to end to get these set up on a dyno. As supplied, the throttle response can be a little 'fluffy' just as I get off idle, but I am sure this can be tuned out. I have found the carbs allow me to run the engine in a stable condition at or below 3.5k rpm on occasion if I pay attention and the road is smooth (I know - heresy). The pick up is phenomenal compared to the standard carbs and in the lower gears the front can get very light under acceleration or lift. You didn't ask, but fuel economy at a steady 80mph (on private roads, obviously) gets into the high 50's. The downside, and this may be because the carbs have not been fine tuned yet, is that slow speed bumpy roads can be a nightmare due to the sensitivity of the carbs to the slightest throttle movement - which can lead to rather jerky progress. As you commented - the choke is handy and works well. Sorry that I can't offer any information on settings (you could always try contacting www.frankmxparts.com for that information). Cheers Richard
I do not have the Mikunis, I have 41mm FCRs, however, over the years when the Mikunis have been discussed, those that have them report very positively. I'm not sure about 40mm on a 750, but the 39mm FCRs on a 750 are meant to be very good. I believe, and I'm sure others can chip in, that the Mikunis are very popular in Europe in racing circles, although this is not firsthand info. Whatever you decide to go for, please spend the time and money to get it on a rolling road and setup exactly for you engine. They are all different, you'll not regret it. Hope you get more info than I have supplied
Cheers Richard, I think I'll stick with these for now and try and get them set up properly. They came from a 900 so probably running rich so should be a safe starting point. BTW an interesting Avatar you have!!
as per reply above. As there are no cheap NOS carbs around (there were 5 years ago!) I'll stick with the Mikuni flat sides and get a session on a rolling road booked.
