Just checked.....yes, it is for drilling out the tamper proof plug which blocks access to the pilot screws....you also get a screw in the kit for removing the remains of the plug.
Two stock 140 Mikuni jets I suspect will cost about £10......finding a none cut about airbox lid??....hopefully someone on this forum will have one.
During the summer I was working to the guide here for my m900. Basically the bike has been returned to stock by refitting g the stock pipes, a stock air filter, and reinstating the airboxlid to how it should be. Carbs apart and cleaned more times than I can remember. So are the numbers in the chart all good to work to? I need to pull it apart again to check the springs are stock as interview earlier pics in this thread.
Seems to tally with what I have.....apologies for the way it appears here. MONSTER 600 - 750 - 900 Tipo carburatore e cilindrata Mikuni BDST 38 B159 600 c.c. Mikuni BDST 38 B216A 750 c.c. Mikuni BDST 38 B129 900 c.c. Note Main Jet 132,5 132,5 140 Idle Jet 40 42,5 40 Slide Spring 730/10026 730/10026 730/10026 Needle & Position 5CJ1alla 3^ tacca 5CJ1 alla 4^ tacca 5C19 alla 4^ tacca Tacche contate dall'alto. SUPER SPORT 600 - 750 - 900 Tipo carburatore e cilindrata Mikuni BDST 38 B159 600 c.c. Mikuni BDST 38 B70 750 c.c. Mikuni BDST 38 B67 900 c.c. Note Main Jet 135 140 140 Idle Jet 40 37,5 42,5 Slide Spring 730/10026 730/10026 730/10026 Needle & Position 5C19-3 - 3^ tacca 5C19-3 alla 4^ tacca 5C19-4 alla 4^ tacca Tacche contate dall'alto.
Just ordered 140 Mikuni main jets from Allens. As suggested, this is a call out for anyone who has a complete airbox lid they might like to sell? Will try the Bay as well. Great advice so far.
Zuff, sorry for hijacking your thread. What is the general consensus of setting the fuel float level and how do you do it?
So, an update. Rebuilt the carbs with stock mikuni jets, needles and emulsion tubes. Serviced all the rest, blew through with compressed air and put it all back together with K&N filter in the cut down airbox cover. New battery, fresh fuel and Caramba! she started easily on full choke. Got her warmed up then backed off the choke and got a nice steady tickover. Feeling very chuffed until I tried to open the throttle. Then major fluffing, cutting out or very erratic running with lots of backfires and flames out of the standard cans. If I let it back down it would return to an idle and if cut out, would start promptly but would not accept any throttle opening. Have I missed something on the carb rebuild or might this be an ignition issue? The bike is 30 years/45k miles old. I plan to start testing the ignition circuits but I am venturing into unknown territory!
Try it with the tank filler cap open. If the breather is blocked, you'll get these symptoms. If it runs with the cap open, find the breather and clear the obstruction. The reason it might start again after cutting out is that there may be enough air seeping past the seal to prevent a vacuum from forming at little or no throttle, but any more demand for fuel will have it cut out.
Airbox lid still available, I got one last year from Stein Dinse 32 euro, except now, plus import duty (?%?) 20% VAT and possibly courier charges for clearance! (not sure how this works on low value items, you might be ok) https://www.stein-dinse.biz/images/product_images/popup_images/24610461b.jpg
So I was very hopeful about the filler cap trick. The bike started perfectly and settled into an off choke tick over after a minute. It then took throttle openings up to 4k but then the fluffing, strangling and backfiring happened. Would settle back to an even idle. It just wont take anything over half throttle. I've posted a video on the Ducati owners Facebook page. File too large for here.
Worth trying. Last set I stripped the seals looked ok but someone had replaced them with round section seals instead of square. Over time they must have shrunk a little and wobbled about under the clamp, allowing far too much fuel to pass through. There is a viton upgrade available for these main jet seals which means they last a lot longer than the originals, even with alcohol typically in fuel now.
daft thoughts have you checked the spark plugs for breaking down also check for air leaks silly things but cheap to check
Checked religiously for leaks. But I will replace caps and leads. Plugs are newish Iridium. I want to check diaphragm in action. At what rpm should slide start to lift?
