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Discussion Starter · #1 ·
Hi All,

First time posting on the SRAD forum and hoping for some advice please, the bike is holding revs if I blip to 6k and release it will stop at 3k for half a second then drop down all hoses are intact and intake rubbers look clean no splits so I am going to carb sync and thus my issue is the carb sync I have as used on my FZS Yam vs the SRAD it seems the connection ports are slightly larger than the ones provided in the sync tool kit can I ask has anyone had this issue or is anyone aware of an adapter to fit the SRAD it seems the fitting on the bike is a M6 fitting is that correct?

Cheers
572511
572512
572513
 

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Discussion Starter · #4 ·
thank you for the reply's managed to get a set off Ebay, have to say the bike is doing my head in; carbs cleaned and sync'd new air filter, no cracks in rubber intakes, screws turned out as per manual TPS resistance tested its within spec (have not set the TPS though as the bike doesn't seem to have a dealer/service port to apply jump lead?? The bike starts straight away sits comfortable on idle nice and smooth. blip the throttle and it holds at around 3-4k then very slowly drops off, if I blip it higher in the range say 6-8K drops off slowly and holds at 3-4k again before decreasing to idle. any help would be greatly appreciated.
 

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something is making it run lean, where are your needle heights? float heights? air/idle screws/o-rings in good shape and out 2.5 middle, 3.5 outside? JETTING!

choke plungers can leak o-rings can go bad maybe screw them on with teflon tape?

how bout the diaphragms? they pliable and soft no tears or leaks? are those o-rings in place and sealing well on the caps, they tend to dry up and shrink?

service manual should walk you through all those hanging idle scenarios.. check you carb internals first and make sure the carbs are sealed..

no change then use a red wd/40 straw tip on a bottle of ether and spray around the carbs, boots, head, hoses, so forth casually and targeted, if the idle increases pinpoint the leak area and investigate, sucking in ether will increase the idle more and indicates a vacuum leak..
 

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Discussion Starter · #6 ·
something is making it run lean, where are your needle heights? float heights? air/idle screws/o-rings in good shape and out 2.5 middle, 3.5 outside? JETTING!

choke plungers can leak o-rings can go bad maybe screw them on with teflon tape?

how bout the diaphragms? they pliable and soft no tears or leaks? are those o-rings in place and sealing well on the caps, they tend to dry up and shrink?

service manual should walk you through all those hanging idle scenarios.. check you carb internals first and make sure the carbs are sealed..

no change then use a red wd/40 straw tip on a bottle of ether and spray around the carbs, boots, head, hoses, so forth casually and targeted, if the idle increases pinpoint the leak area and investigate, sucking in ether will increase the idle more and indicates a vacuum leak..
thank you for the information only just managed to grab some time on the carbs, so I have measured the float heights (slightly out of spec) adjusted to 7mm, choke plungers look good as do the diaphragms. however upon inspection of the main jets it looks like the bike has been jetted pilots are correct for standard 12.5 mains though 1&4 are 135 2&3 132.5 carb spec UK 34E6 T835 according to the manual they should be 1 - 125 2,3 & 4 122.5 I have the pilot screws set at standard 1 & 4 31/2, 2&3 2 1/2. If I stick with the current main jets does anyone know what spec to turn the pilot screw to? otherwise is my best option changing back to original? and final would the bigger jets cause the hanging RPM symptoms?

Cheers
 

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I would return those jets back to original for a solid base.. go back to all stock settings as a base starting point.. no matter what pipe and filter you have.. some people got a hold of these bikes and didn't care about how they ran down low or off idle, all they cared about was top end power so they put the fuel to it..

what are your needle clip settings? go back to stock

also check for vacuum leaks, ether spray direction at suspicious areas so forth, if it idles up it sucking it in, make sure the entire intake systems is sealed up and tight..

have you checked out the factory pro sheet for tuning these CV carbs?


once you get your base setup then go through this work sheet and tune them accordingly, these guys are pros, they tuned the carbs for all the AMA, and various other series race bikes in the day when these bikes were winning races, as they say there is no scientific magic number each bike varies, but these steps are rock solid and should get you running very well, best seat of the pants I know of..

of course a sniffer and dyno tune might get you more efficient and dialed in but who has that?

this sheet is what I used and my 600 runs tops.. better than my Busa and its FI..
 
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