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seals for carb

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  • seals for carb

    Hi all

    this might be a stupid question, but i need your help.

    I have had some issues with my idling and low power.

    Figured I didn't clean the carbs properly. So I took them off again and went through them.

    They were clean. But I noticed that the rubber blind plug, for the Pilot Jet were loose. Some drop out, when I took the floatbowl off.

    So i'm guessing that this could be my main issue.

    But I can't find any online?

    Are these not avalible or am I just rubbish at online searching?

    Could you help guide me?

    It is for a 89 Gsx 750F

  • #2
    I bought some a couple of years ago just straight from my local dealer look up the part number give em a ring to see if their available I didn't have any trouble getting them.

    Some on here have said they need replacing and thinking mine were a bit loose replaced them I couldn't tell you if it made any difference and the new ones didn't really seem any tighter than the old ones neither fell out of the tubes though.

    If they are are still in the pick ups tube then probably tight enough I don't know.

    TBH I don't think that is your main problem though the jet will only meter a set amount of fuel GSXR carbs don't have the bung but draw the fuel straight from the bowl is just the gsxf 750 that draws fuel from the main jet pickup tube for some reason and some have run without the bung the question mark here is can the pickup being shorter can this be effected by lean angle and fuel level in the bowl. The gxsr has a deeper pickup tube

    Lots of theories not many answers unfortunately but you can just do it for your own peace of mind.

    anywho check with your local suzuki dealer I'm sure they are still available the bigger issue with these carbs is worn slides and dirty pilot jets/needle
    Check this

    excessive wear will accelerate emulsion tubes and needles

    but you need to check there is absolutely no vacuum leaks and as lots will say clean clean and clean again.

    Once I clean and replaced all available parts and jets it cost lots but worked fineHeres my endeavour chasing a vacuum leak
    Originally posted by Lachie View Post
    Last update

    So I've spent the last couple of weekends and odd times annoying the neighbors tuning the bike.

    So whats wrong with revving a bike at 11:00 at night some people just don't have a sense of humor........... Meeh!

    Replaced the choke slide rubbers and the little rubbers in the bottom of the Pilot jet tower (to be honest even though the ones in there were not very snug and fall out by themselves It didn't seem to change anything)

    So the carb setup I've finally got is 5EZ61-3 needle jet, 105 Mains,37.5 Pilot jet.

    But it's still not 100%

    It'll pull WOT great

    Dropped the needle one notch to eliminate the stutter in the midrange great

    Next was to try and sort the pilot started at 1 3/4 as per the manual for this jetting and slowly worked my way up cause that just wasn't working had massive low speed stutter.

    I thought the floats were pretty right I had checked them before putting it back together but when I finally got to 4 Turns out on the pilot jet rechecked them again

    Btw I resync'd the carbs every second time having them out with the Manometer

    The setup - Start

    Getting better nearly there can spend so long tweeking this (why is that middle screw at such a hard to get angle??!!!)

    So rechecked the Float heights and I don't think I must have done it right the first time and ended up adjusting them all to around 14.5 mm which was about a mm lower then were they were set so this should make the bike a little richer. Put the pilot down to 3 1/4 and was much better but needed more.

    Down to 2.5 and was way worse so ended up on 3 turns out and pulls really nice when warmed up.Great

    I ended up syncing the carbs at 2250 revs I had started out just doing it at about 1500 revs as I had read you should just do it just above idle but decided 2250 was probably a better place to do it. I don't know but anyway.

    The Factory Pro tuning says you should tune the low end for smooth idle and 4k 2nd gear operation which it does, in fact it goes great at any acceleration.

    So now it is just at 5th or 6th gear cruising it has a little lag at 4,500 to 5,500 revs roll on and if I slightly drop the throttle a little feels like it's starving which is more just annoying then anything.

    Having spent so much off time trying to sort the tuning I've just decided to get it back on the road proper and ride it for a while maybe if it gets to me too much or when i get bored I'll rip it apart again and try the float at 14mm i'm thinking it maybe still be a little lean in that area or maybe play with the needle again to see if raising it back up cures the lag in the 5-6 gear range midrange cruise state, but is accelerating so great in all other ways, I don't want to stuff it up .....


    cause it was quick and didn't take a lot of disassembly I lifted the needle back to the original middle position and it fixed the leaned out midrange but somehow the lowend was bogging down. So i relented and took it all apart again. Went over the float heights spent a bit of time on this and made sure they were all at 14.5mm turned the PA screw down to 2 3/4 and vacuum sycn'd the carbs at 1750 this time.

    Now it pulls absolutely great through all the rev range and there is just the slightness hesitation @ 5000 in 5th and top at cruising speed which i can live with ATM. Some thoughts on this is either the pipe has a little flat spot around this range which is why it's been difficult to tune this bit out or maybe I could go one size up in the main as it's just struggling a bit just on the needle.

    Oh well that's maybe a challenge for when I really get bored LOL
    Last edited by Lachie; 08-19-2020, 03:32 AM.
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