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Help GSXR carb help please

Discussion in 'Suzuki 250cc In-line 4's' started by monsigna, Dec 5, 2014.

  1. monsigna

    monsigna Active Member

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    I have a small tin of red grease, i will be coating the rubber when I get in. The brass has been soaking all night and day, so hopefully it should be clean. I have paraffin washed the carb bodies today and treated to a can of carb cleaner spray. It's not looking too bad, but i do like to go that extra mile. So i will be using good old elbow grease later. I have a trick up my sleeve
     
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  2. monsigna

    monsigna Active Member

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    All four main jets were completely blocked, cleaned now, toothbrush in the sink and lashings of elbow grease. The carb cleaner didn't do to much if i'm honest. still...job done now.
     
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  3. monsigna

    monsigna Active Member

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    when you remove the float bowl, looking at the carb float area, there is a brass pipe sticking out (about 20mm) with a minute hole in the end, does this 'pipe' need to be spotless/not blocked? I guess it must, but one is being a git to clean out. a thin piece of wire is my only hope.
     
  4. GreyImport

    GreyImport Administrator Staff Member The Big Cheese Contributing Member

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  5. Murdo

    Murdo The Good Doctor Staff Member Premium Member Ride and Events Crew Contributing Member

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    ALL passages and jets need to be clean or you will be doing the rebuild again.
     
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  6. Willrcr15

    Willrcr15 Well-Known Member Premium Member

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    The jets are easy to clean as you have found, it's all the consealed galleries in the carb body that need to be clear.
    Get some 3bond/Subaru upper engine cleaner/ what ever else it's called & get into the alloy parts. Give them hell with compressed air over & over.
    I find the carb cleaner with the extension tube is good at seeing if it come out the other end of the galleries & you start to get an understanding of what get does what. Make sure all the choke system is in good order & shutting down or you'll get a very rich issue. In that sort of condition, don't be surprised if she floods when you turn the fuel on, those inlet needles hanging off the floats might be shot. If you replace them, keep them & use them as a honing tool with some fine lapping paste to clean up the seats so the new ones seal off as best as possible.
     
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  7. Mclaren

    Mclaren Well-Known Member Contributing Member

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    For scrubbing use a brass brush couple of bucks at auto shop won't damage alloy or jets mate

    Also carby cleaner works and reacts best when part hot I boiled kettle and Poured over carbs so they hot alloy transfer heat well then hit with cleaner and let sit and wash off with hot water then I final flush with fuel
     
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    Last edited by a moderator: Dec 7, 2014
  8. Simon

    Simon Well-Known Member Premium Member Contributing Member

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    water bath..then dry and 'silicone' anything rubber as per maelstrom.. they'll distort and perish otherwise..save all the seals you can boss! Anything metal I use..mmmm..its akin to parrafin..well paraffin and 'gunk' mixed..clears piston groves in a standard 'rich' running engine within 24 hours..that's properly clear not half baked i.e pretty much as new..add in some compressed air through the carb passages in your case and you wont go far wrong mate..it'll dissolve varnish and fuel residue in much the same way as commercial paint stripper but its about twice as potent..5l parrafin and a litre of gunk..it'll work again and again too so don't get rid of it when it goes discoloured..the aussies are a bit posh calling it threebond lol..(comments not invited!) but its sold as threebond..their vinegar or ammonia smells a bonus lol!!!! Never used the threebond stuff but if the parrafin and gunk doesnt work it'd be my next best option! Good luck matey, cheers si
     
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  9. monsigna

    monsigna Active Member

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    Thank you good people for all your tips/pointers, I have hit a bit of a wall to be honest....I have only managed to remove one out of the four 'chrome jets' the other three are stuck fast, I have tried all the tricks in the book to free them, one which is stuck can only be screwed IN!!!! it wont come out!, im not holding out much hope for them :-(
     
  10. soames

    soames Well-Known Member

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    Just had the same problem on my pilot jets had to grind a small screwdriver down to cut into the brass in the end but heat does seem to help sat mine in hot water for at least 30 mins
     
  11. monsigna

    monsigna Active Member

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    The slot heads are shot, one out, three stuck fast...:headbang: just don't know what to do now.....where's that towel?....it might get thrown in at this rate...had a job to remove the front wheel! the nut was stuck fast, got it off eventually, and found the axle was rusted in place!, eventually got the front wheel off, both front callipers were seized to the discs, they had to be malleted off....they are also very crusty, the last owner said 'you will be ok with the front callipers, I serviced them before it went into storage'....yea right!, just a bit down today, nothing is going right, I have found some second hand carbs, I have them here, they look ok, the jets move in and out ok, but two sliders are very jammed in the housing.....
     
  12. soames

    soames Well-Known Member

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    Well if you have a second set go for wot is best sliders can be free'd up then silicone spray to lube I know its a sod took me nearly 7 hours to get one pilot jet out on my second carb set only to find missing parts and butterfly troubles
     
  13. monsigna

    monsigna Active Member

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    Oh no soames!! did you sort it out eventually?....I have soaked both ends of the sliders with lube, they sat for an hour, but still no joy, I cant believe how stuck they are! I resorted in using a flat blade screwdriver to try and coax the stuck slider....but the body of the slider simply splintered off! I wasn't giving it much beans either....good job I have spare ones now. ive had enough today, feet up I think.
     
  14. monsigna

    monsigna Active Member

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    Quick update. I have got the two sliders out of the new donor carbs, they were stuck in with brown treacle type stuff. So that's good. The idle jets move freely, so that's good.
    I do have another carb question while I think about it. My old carb needles are very tapered, the needles on the donor carbs are fairly uniform. I take it that my original needles won't work in the new carbs without changing the needle seat's (which I'm not willing to try) also, the brass jets are numbered differently. Am I right in saying that my original carbs (very tapered needles) are for a more sporty ride?

    One other difference i have found is the rubber hoses, my original carbs have a 'T' piece in line which goes to the fuel tank (vacuum? ) and the donor carbs don't have the 'T' piece,the rubrubber hose just goes from carb to carb. Can anyone please explain the difference? And how do I overcome this on the fuel tap (no vacuum pipe from new donor carbs). Thanks for the help so far gentlemen.
     
  15. Willrcr15

    Willrcr15 Well-Known Member Premium Member

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    Whoa ! different carbies, your heading into a dark & lonely place.
    What did the spare set of carbies come off ? Similar model, same year ?
    The vacuum tube will open the fuel tap/diaphram when there's suction from the inlet as soon as it turns over.
    The fuel lines should be ok wherever they come in from, the fuel needles meter the quantity as long as there's fuel there to deliver.
    The needles go down into the 'needle jet' which has the main jet screwed into the end of it, the steeper the angle on the needle the quicker the delivery of fuel from the main jet. The main jet may also be bigger than the one the original set?
    This might be all ok if you have an open exhaust & a free flowing inlet filter.
    Try them first & see how it goes, you might get lucky, otherwise find a set of the correct carbies.
    Carby engineering is a precise black art, the most minute discrepency can have large impacts.
    Have a look at the exhaust burn when you rev it on the stand or if you can follow it on the road & see if there's a grey puff of smoke when it's rapped on, that's unburnt fuel, too rich, too much fuel for it to burn clean & in effecient, she'll be down on power & over in fuel consumption.
     
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  16. monsigna

    monsigna Active Member

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    Thanks bud, the carbs were advertised as the same make/model/year as mine, and are exact except for the needles & no 'T' piece in the hoses. im stuck with the original carbs as I cant move three of the mixture screws. what I was going to do was clean the new donor carbs and re-assemble as they were, the only issue really is the lack of 'T' piece, can I just pop the T piece inline? there is actually a join in the new hoses, so I was wondering if their used to be a T piece in previously......mmmmmm
     
  17. Willrcr15

    Willrcr15 Well-Known Member Premium Member

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    Sounds like that'll work but you'll have to cap off the old fuel inlet that was feeding the carbs, what is it, a brass tube coming off one of the carbs?
    Cap it off good & secure so it doesn't leak.
    As far as the vacuum line is concerned, you can disable the diaphram in the tap under the tank, but that's a bid dodgy. I'd be trying to find a hole or something on the carby or on the inlet manifold to connect the line to to operate the tap diaphram. The inlet needles become the secondary failsafe for fuel shut off then.
    It'll be interesting to see how it runs with the new carbies. Keep an eye on the plugs if it's a goer, maybe too rich for the plugs, maybe have to run a lower number plug but that's getting off into another world again. In your cold wet world you will be running different plugs & maybe carby settings & jets anyway, your fuel will be different to ours, our range is 91, 95 & 98 octane at the bowzer.
    Anyway it's all interesting, keep us informed how you go.
     
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  18. monsigna

    monsigna Active Member

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    Will do. Pictures soon
     
  19. monsigna

    monsigna Active Member

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    So am I right in saying that the old original set up had two fuel supplies? There was a large bore fuel pipe coming from the main outlet on the fuel tank, and the smaller bore pipe also came from the tanks other outlet, and went down to the T piece/mixture jets.
     
  20. Simon

    Simon Well-Known Member Premium Member Contributing Member

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    how do mate..and persevere!!! pictures required please..The vacuum pipe and petcock is easily sorted through blocking off the 'pick up' which will be on the inlet stubb of cylinder #2 (left to right sat on the bike)..fit an rgv 250 1989-1996 petcock and the fuel side will be fine..no vacuum required to operate the tap..the carbs..that's another matter..will isnt wrong when saying its a bit of a black art lol..your on the 27 carbs at the moment on the 72a..easiest way would be to source a set of slingshot 29mm or 32mm (sp)carbs of the later 73a and make inlet rubbers to cater for the offset to suit..failing that then i'd go for pretty much what your doing and try and make one good set from two..but different tapers and jet sizes has me worried..these bikes are so sensitive to carb set up they wont allow for any mistakes..if your sure there exactly the same then i hazard retrospectively fit the t piece to the donor carbs and see where your at????? good luck fella and keep your chin up :)
     
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