help with carb tunning

[PHILB]

hi can anyone in the lincolnshire area help me with setting my carbs up properly with an aftermarket exhaust? (gsx 750 inazuma)1999 carbs have been stripped & cleaned also float hight bang on checked diaphram`s & piston`s everything ok, but dont know which jets ect,to apply, obviously cash will  be paid, cheer`s  yours phil  

[TonyGee]

how does the bike run ? has it still got an airbox ? an exhaust change or an end can doesn't really make much difference,  ive just bought myself a colourtune to set mine up, works a treat.  

[PHILB]

sorry for the late reply tony,when i ran the bike before stripping carb`s it was surgeing alot,especialy around 50mph, that`s the main reason i stripped & cleaned the carb`s in the first place, i must say though the carb`s were realy clean no build up  of varnish or gum ect,& yes to the airbox bit mate everything on the bike appart from the exhaust is orig,did try a new tps unit a few month`s ago with no success, just getting a bit fed up throwing money at it for nowt, also tryed new dyna coils which made no diffrence either, so ive put orig one`s back on for know, i bought it with this new full system on & it`s ran like this from when i bought it, i will bear in mind the colour tune kit though mate,cheer`s,were did you pick that up from if you dont mind me asking? was it the bay

[TonyGee]

yeah got it off the bay £40 new.  they are a good bit of kit and can help get your mixture set right through the rev range.  have you got another exhaust system to try on ?   

[Gixer1460]

10 hours ago, TonyGee said:

yeah got it off the bay £40 new.  they are a good bit of kit and can help get your mixture set right through the rev range.  have you got another exhaust system to try on ?   

TG - you are overplaying what the Colourtune is capable of! They are really only of any use at idle and to correct adjustible idle AF mixtures as this is an area where the engine isn't under any load. To correct any other range, the engine should be under load - either on the road or a dyno - and trying to read a Colourtune out on the road could be pretty dangerous LOL!, and if you are on a dyno, it should be equiped with AFR monitoring making the Colourtune surplus to requirements. 

Don't get me wrong, CT's are great devices for an annual garage check / tune up of idle running, just like a set of vacuum guages, just not loaded / under power tuning!

[Nik]

Phil, the surgeing could be caused by leaking carb boots. Run the engine and spray some motor starter on the boots, to see of the revs change. If not, your boots are fine, and you can continue investigating your carbs.  

[TonyGee]

53 minutes ago, Gixer1460 said:

TG - you are overplaying what the Colourtune is capable of! They are really only of any use at idle and to correct adjustible idle AF mixtures as this is an area where the engine isn't under any load. To correct any other range, the engine should be under load - either on the road or a dyno - and trying to read a Colourtune out on the road could be pretty dangerous LOL!, and if you are on a dyno, it should be equiped with AFR monitoring making the Colourtune surplus to requirements. 

Don't get me wrong, CT's are great devices for an annual garage check / tune up of idle running, just like a set of vacuum guages, just not loaded / under power tuning!

yeah i agree things are different under load but it'll get your mixtures in the right ballpark, it does say in the instructions to go through the rev range !!!  my old XS11 had a small flat spot at 3-4000rpm and i could see it was running weak with the colourtune, so lifted the needles and the flat spot has gone with a nice blue flame.  it takes the guess work out of it and at £40 its a dam sight cheaper than a dyno run for us who are skint