Well that was bizarre! Still ran rough as nails under 2k, would stumble, spit, cough, falter, cut out? Good plug colour, tried altering the mixture screws to no avail? Wouldnt tickover either? No effect on the idle screw until suddenly on the next turn it would be doing 3k revs?? Dammit... I checked the plug colour again. Couldnt be the plugs at fault as they were iridium's, DCR8EIX bought in Jan this year, damn things are Immortal!! I had a spare set of new plugs sent to me with my C/Cycleworks 35,000v coils, NGK DR9EA, recommended by C/Cycleworks for use with these coils? Hummm... I fitted the DR9EA and started the bike. Bike was instantly cured, ticked over nice, no sign of any faltering, missing, spits or sneezes?? I thought the Iridium's had a life of like 30,000miles? Have these coils ate my Iridium's in like 2,500 miles?? WTFH! The only prob I have now is slow-to-return-to-idle revs on a throttle blip, I have that down as running too weak, perhaps due to the different heat rating of the plugs? Do I need to fit standard plugs (DCPR8E) or buy DR8EA? Im thinking the DR9EA may be for a Yank carb setup...
Or turn the throttle stop screw down a bit...... Could also be the air cut-off diaphragms. I have also found out that my DJ springs are too short (according to DJ) which could be causing fluttering slides....lucky I have some spares to stick in instead. AL
Solved the problem today. Rode my kwaka! My god it was like going forward in time 800 years. Will be taking her down to South Of France instead of Duke just because I need the power and smoothness over that distance. Back to the Duke, couple of mates are convinced are the carbs. Sounds like you've tried a few things, I need to drum up the patience to have a look at all these things. In the petrol station I was literally stunned at what a good looking bike the SS is. It made me start thinking about hybrids. Bimota anyone?!!
The more I look at your original post and compare your symptoms with what I had with my bike, plus getting to grips with how those carbs work, I think it could be either the choke mechanism / choke units; or maybe the air cut-off diaphragms. AL
flashed tonight by speed camera. I'm assuming the f ing speedos on these bikes are sometimes incorrect??!!!
I bet the idle adjusters from Suzuki Mikuni slingshot carbs will fit ? its the thing bttm right going to the centre of the carbs there are Mikuni BST38's from a GSXR750L Another thing I learnt with working on the Suzuki Mikuni Slingshot carbs (ours are basically the same) is that the black plastic slides and the white plastic housings in the carbs can wear and then this causes the needle to wear the top of the jet tube oval , nice ! I've got a set of slingy carbs somewhere which if I find will photograph to show how bad they can get. View attachment 5717
Have you checked for air leaks , this is exactly the same as what happened on my Suzook 750L , turned out to be an air leak where the carb joined the head, I'm a big fan of Red Hermetite for petrol use and sorted it using that on all the inlet gaskets.
Had a look at the GSXR750/1100 Mankini's :biggrin: of 1990 - 92 vintage, the earlier 90-91 carbs had a thumb twiddler like this: Suzuki GSXR GSXR1100 Good Used Original Carburetor Set Carbs 1991 #US | eBay Not quite long enough to clear the cable pulleys, would still be a faff?? The longer cable adjuster has a rep. for breaking, meaning more faff to remove & replace the broken bits. The TDM850 had a pair of Mankini CV38's with a cable adjuster, apparently the cable has now been discontinued? No point fitting a second hand one as I would be waiting for it to snap etc. A further search for a twiddler... came up with this: KAWASAKI KZ1300 KZ 1300 MIKUNI CARB CARBURETOR THROTTLE STOP IDLE SCREW 79-82 | eBay Looks to be the right thread & length to be convenient? Would mean using the float-bowl sidemount adjuster support to stop the longer adjuster jibbling around - may need another made up by the look of it? No prob. Fed up with lying underneath the bike like I'm asleep/having an intimate moment with the bike just to adjust the tickover??!
Don't use the 1300 one....on the bike there is nothing to mount the stabilising bracket to, therefore vibration will be an issue as I reckon the d*mn thing will wiggle around like mad and undo itself. The long one on the bank of carbs above would be OK, I reckon.......the awkward bit is where to fix it if too long, as there is too much cable twist....... AL
Bought the 1300 one yesterday, am committed, lol! Can make up another stabilising bracket, would have to fit under the SS cable holder anyhoo? Not impossible...
To what will you fix it....??......and you will still have to stick your hand in a hot engine area....... PS.....did you have a good look at it first?.....the thread bit seems to be bent out of alignment with the rod....hopefully it hasn't crushed the fine thread together... AL.
I should be able to use the two carb float bowl screws as per the Kawa bracket? Will probably have to fab another bracket up, or weld a washer on the bottom of the SS cable bracket where the U-shaped bend is as per bottom photo? Have made worse!
An awful lot of work as opposed to joining a trip meter cable to the screw (which could have been done for £0)..... Still, a bracket to hold the cable knob would be needed anyway. AL
Granted! I am unable to locate a tickover screw to get this cable made up, searches brought up the longer Kawa screw which I assume to have the correct thread? I can't see Mankini messing with different thread sizes on said screw? Yes - would still mean sticking my hand into a hot engine area, but should now be able to be done knelt by the side of the bike with a finger-&-thumb twiddle rather than led under the bike needing a screwdriver? All good. :smile:
It seems that screw size is common across many of the Mikuni carbs.........when you eventually find one, give me a shout. Pity the balance screw can't have the same thing.........I can't even see mine when laying on my back....it's hiding higher up behind the float bowl breather pipe, so it's Maglite in the teeth, long screwdriver for probing, wedge under the unbolted oil cooler, so I can get the screwdriver under it, burnt fingers pushing the oil cooler a bit more, burnt arm on the exhaust pipe etc etc etc...... .........and when I finally get the screwdriver located in the balance screw, I can't see the balance gauge, so it's hold the screwdriver with fingertips and struggle onto my knees from the laying position........then sometimes if the engine isn't running, when I start it, the screwdriver jumps out.... ....what I did find though, is to use the smaller than normal crosshead screwdriver....it locates much easier. AL.
Ummmm maybe change the balence screw - clearance permitting - for a longer one, a tickover screw maybe? Have found the LED headtorches to be priceless when needing three hands, they are cheap enough at most marketplaces/Wilkinsons etc? Mine cost me £3!
Al, a top tip is to use a small Maglite type torch and tape it to the shaft of your screwdriver. Viola! both hands free and the light always points to where the tip of the screwdriver is. Used to work well for me when my 900ss had Mikuni's fitted. WW
Yep.......but not with a top mounted oil cooler / carb heater pipes in the way.....can't lift the cooler high enough for much more than the screwdriver, hence using a wedge. AL
Doh!! To steal a phrase from another thread, that's p*ssed on my chips :smile:. I can see why the remote adjuster idea was so appealing now. Incidentally, I liked your little mounting bracket fixed to the frame for your adjuster to mount on. Might pinch that idea for the remote adjuster on my FCR 41's. At the moment it just hangs from the left side of the frame under the airbox. WW
