I only noticed this thread today, which is unfortunate as I spent a lot of time years ago setting up a stage 2 Dynojet kit on a 900ss by using lambda sensors and appropriate gauge. What I learned might have been of some help. The standard float heights were about 10.5 to 11mm but the Dynojet kit has them set at 14mm - which makes a big difference to mixture strength. I used the standard springs as the bike just felt "better" than with the weaker Dynojet ones. I fitted the Dynojet 150 main jets with a K&N filter in standard airbox with trumpets removed and straight through type, road legal end cans. 144 main jets were best with the standard cans - if I remember correctly. *A big word of warning about removing the trumpets from the airbox lid on the standard carb setup: On full throttle the oxygen gauge was showing just into the rich with the trumpets in place. With the trumpets removed the gauge would not show anything on full throttle - in other words it was so lean that it was out-with the measuring range! Not good. If anyone has removed their trumpets then make sure you have at least fitted larger main jets.* Initially there was poor low speed running when trying to go slowly in traffic, for example. Lurching and difficult to control. Replacing the very slightly worn emulsion tubes sorted it out. Turns out that the Dynojet needles are very slightly thinner before the taper than the standard ones which obviously lets a bit more fuel past. Wasn't noticeable with the standard needles though. If I remember anything else I will post it.
Thanks Mick-Bob. I removed the dynojet parts and have put everything back to stock...carb internals, airbox, trumpets, filter. And standard silencers.
Quick question, are your floats hollow or solid? The reason I ask is that I recently went through something similar (admittedly on the Mito) as it kept fouling plugs running way too rich. I replaced the various jets and needle valve and seat, idle screw and set the float and needle heights but that didn't fix it so I then changed the coil, plug, cap and lead, checked the wiring, fuses and alternator and neither did that. Having taken the carb apart again to clean it, for some reason I shone my head torch through it and could just about see a tiny quantity of fuel sloshing about inside one of them. With a new set of solid floats from eurocarb fitted, it's running better than ever. Might be worth a check as it's pretty simple to do. In the past I have also fitted a number of dynojet kits included a stage 2 in my M750 and never had a problem with any of them. The M750 was noticeably better after the kit had been fitted.
The situation with the bike got worse and worse to the point it would not start at all. Remembering the advice of my old physics teacher when faced with an apparently insoluble problem, I went back to basics. 1. Ensure a spark. Ive swapped everything out bar the plugs which were fairly new ngk iridiums. Put a new set of conventional plugs in. Still no life. 2. Ensure a fuel supply. Plugs did get wet after cranking and I could hear the fuel pump running and a gurgle of returning fuel. Nevertheless, i connected up a remote reservoir and tried again. After about 10 spins there was a tiny cough. Cranked again and she ran! So some issue with the tank fuel feed, not surprised given the ridiculous internal plumbing. Will be taking tank off for investigation soon. Will feedback findings.
internal fuel pipes have been known to split with age could be pumping fuel back into the tank i would change the filter while you are there as well the pipe in the tank is not normal fuel pipe it is a special type for being immersed in fuel and with this modern fuel worth making sure it is compatible
Ok. So fuel supply is ok. I have taken the carbs off and would like to get them professionally overhauled. Are there any recommendations for someone who can do this please? Many thanks!
try these Allens Performance Ltd. - Allen's Performance provides parts for road racing, drag racing, motocross, trials enduro, speedway, grasstrack, circuit car racing and hill climbs. i am sure there is another one but cannot think of them for the moment
Steve Doran Motocarb (Mikuni Specialist) Crosby Liverpool telephone 0151 924 5383 email [email protected]
Hi Zuff Just seen this thread There’s a couple of really small filters fitted on the fuel lines, one in the original Y piece joint and one at the carb fuel inlet Probably a good idea to check if their clogged up or better still remove them and try again
For me it's the total opposite. I paid Allens Performance £170 eleven weeks ago. After I paid, the communication has been VERY difficult. No information from their side. Only answered my emails when threatened. When the parcel was sent they did not fill all the needed information to send it in to EU, so the parcel was sent back by Swedish customs. This was 1,5 months ago. And Steve haven't yet fixed the problem. One call to Royal Mail from him would probably solve this, but... He is just not interested. After all, he has already get paid.
I too had no response from Allen's when I enquired about a carb rebuild kit using their web contact form. I ended up ordering a Japanese aftermarket kit by Keyster from FleeBay. It wasn't particularly cheap but came with needles, gaskets, all the jets, seals required and seems good quality as I'd expect from the Japanese. It was also delivered very promptly. https://www.ebay.co.uk/itm/Ducati-S...2349624.m46890.l49286&mkrid=710-127635-2958-0
OK, so I bit the bullet and sent my carbs off to be professionally rebuilt. Used Coln Engineering in Gloucester. They did full ultrasonic clean, complete rebuild with all new internals (keyster) and test all for £226. Took about 1 month but communication was exemplary and carbs came back sparkling. Highly recommended. Now just got to refit carbs and airbox. My least favourite job in the whole world....would rather clean u-bends with my tongue! Tonight, got the carbs on OK but the airbox has defeated me....I think the fuel inlet pipe and breather are fouling. Anyway, will go back tomorrow with a clear head.
Just stripped and rebuilt mine with Keyster kit which cost just over £100, so that price for a professional clean and rebuild doesn't seem too bad. Getting one seized pilot jet out was an absolute nightmare and ended up involving a good local engineering firm to get out the previously mullered screw. Having had to remove and refit twice now, I agree with you regarding what a right pain in the backside the whole process is just to get them out and refitted. I HATE IT! Routing the cables and pipes correctly is a real fiddle, especially as the more you refit the less room you have to see and refit the remaining bits correctly . Found that I had to experiment with the float height and pilot mixture screws to get it to stop popping at idle. You may be lucky but don't expect it to be a simple case of fit and forget . Ended up with my flat heights set to 12.5mm (see the late, great Aquerbus posts about that on here) and each pilot mixture screws set slightly differently. Still got a very slight hesitation at around 4900 revs in 1/8 throttle if you crack it open quickly but I can live with that at the moment! Good luck with the refit, take your time and close the door and walk away if you hit a snag, that often helps in my experience .
So finally got everything fitted. Started her up. Got a good tickover and was able to back choke off. But she just would not take any throttle. Popped and banged just like before. So she has essentially new carbs with standard airbox and cans. All new ignition system Correct valve clearances. Im at a loss so its off to Louigi Moto.
Rich is top man and will sort it out for sure. Can be really frustrating to set up, especially if you have to adjust float heights as you have to repeat the painful remove/refit process until you get it right. 12mm float height is a good starting point though, not 14mm which is often quoted. Check out some of the carb threads on this forum for more info.
not been involved with this thread, too many cooks etc, but, apologies if it's been covered/replaced - have you tried different igniters? Below is std/correct for virtually all bikes with Kokusan:- your symptoms in last post do fit in with these (one or both) misbehaving, and might be worth trying a third set even to definitely rule this out.
I don't know if this has been mentioned before but if the pick up wires are reversed you will get very similar symptoms. Some replacement pick ups from Electrex came with polarity reversed.
