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Three Questions Already

Discussion in 'Suzuki 250cc In-line 4's' started by Laceysnr, Jul 23, 2019.

  1. Laceysnr

    Laceysnr Member Premium Member

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    Did a bit more on the bike tonight, got the old plugs out and dropped some oil into each cylinder to soak for a week or two, and then turned back to the carburetors. I feel like someone's been into these before, because one of the eight screws in the top caps is different to the others, and another was torqued crazy tight. Unfortunately the tight one rounded out yesterday while I was trying to shift it, so tonight I soaked it some more with WD40, cut a groove in the top and after removing the other three in that cap so I could give the top a wiggle I got it loose with a flat head screwdriver... clearly I'll be replacing that one.

    Anyway, two questions on the carbys:

    1. According to this guide: http://teamghettoracing.com/mechanical/carb-efi-work/suzuki-across-gsx250f-carb-overhaul/ (I'm sure everyone has seen this!) once the caps are off you can just pull up the diaphragm and the slides, but mine pulls up a little and then hits the stops, the slides themselves won't budge, do I just need more WD40 or is there something holding them in place?

    2. The four main jets came out fine, and three out of the four pilot jets did also. Unfortunately one pilot appears to be rounded off. I didn't put any more force into this than the others and get the feeling it was done previously... do I have any good options here? I'm assuming having a single pilot jet not super clean won't be the end of the world but it's obviously not ideal. The others are all soaking in carb cleaner, I could only see through 1/7!

    And then the third question - this is definitely a newbie one (first bike I've done this kind of work on). The tank wasn't stored full, which sucks, but it doesn't look terrible either. I topped it up with fresh fuel and gave the bike a shake around, then tonight pulled the fuel line off the pump and opened the pet cock both ways to run some fuel out into a container (see image). There's no major crud in there, but the fuel clearly has rust in it, this is literally the first fuel out. How bad is this? Can I get away with running a full fresh tank through and seeing how it goes? I'll be putting a fuel filter inline before the pump before I try running it.

    IMG_20190723_214733.jpg

    Last but not least, I reckon something used to live in this bike that liked to snack on slimy things, check out what I found underneath the carbs!

    IMG_20190722_223456.jpg
     
  2. Murdo

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

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    1, if the screws are chewed then go to a bearing/bolt shop and renew them all (will save you grief later and will cost a couple of dollars).
    2, ALL jets MUST be removed to properly clean the passages behind. You may need an 'easy out' extractor to get it out, but the jet has already been stuffed so a new one will be required anyway.
    3, drain the fuel out and fill the tank with cheap supermarket vinegar and leave for a couple of weeks. Drain and flush with water until clean and immediately put some petrol/oil/metho mix in and roll around to coat all surfaces to prevent flash rusting. When ready to put back on bike drain out and fill with clean petrol. Use a good paper car type filter to be sure of clean fuel to your freshly cleaned carbs.
    Amazing what can live in undisturbed areas.
    Happy running.
     
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  3. Andych

    Andych Well-Known Member Premium Member

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    AS for Question 1... that guide is invaluable with an Across.. Yes the slides should lift up. Fold up the diaphragm and slowly lift up... a little WD40 should see them come out, there are no stops at all.
     
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  4. Jethalter

    Jethalter Active Member Premium Member

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    1. As others have said, the slides should just lift out, try pushing the slides up with your finger from inside the carb rather than pulling the top. Saves the plastic pieces. You'll probably find your slides damaged and not a cheap fix. I went through 3 sets of carbs to get 1 set of acceptable slides.

    2. Im personally not a fan of easy outs, but this technique i use works for most things. Get yourself some torx allen keys on the small size, drill the smallest hole you can thats just under the torx key size, dont go too far down, you have about 5mm at most you can in the pilot. Tap the torx bit in, the star teeth will bind and grab in on the brass pilot. Then use a heatgun on hot gently around the aluminum pilot channel, making it warm. Then with a small spanner on the torx turn it like you would to remove. Should come out easy. I had to do this on one of my pilots.

    3. Rust in tanks is an issue, generally what the others have said here is fine. Its a super pain to get the tank out also. Best spot for filter is straight after the fuel tap. Its down low and still flows good, i've had issues near the pump but thats probably just me. Also check that your fuel tap has the screens intact, i've had one tank that they were unusable and another that are perfect.
     
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    Last edited: Jul 24, 2019
  5. Laceysnr

    Laceysnr Member Premium Member

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    Thanks for all the input. I guess if I know the sliders aren't hitting a stop I can just use a little leverage from the bottom. I've tried pushing with my fingers but they still stop at the same point, and it's both sides which is weird.

    I'll try a tank full of vinegar with it in place on the bike to start with to see how clean I can get it, if I can avoid dismantlting the whole back end to get to it that'd be a bonus! I like the torx key idea for the jet, I've got a few that might even fit without any drilling, so I'll start there and work up to drilling/easy out. Will have to be sure all the carb cleaner vapour is dealt with before I crack out a torch :D

    New fuel tap and filter should be arriving today :thumb_ups:
     
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  6. Laceysnr

    Laceysnr Member Premium Member

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    So when I said I had a few that might fit without drilling, I wasn't wrong. The first two I tried were too small and wouldn't get a purchase on the pilot jet just with it's existing hole. Worked my way up, and finally had one that took a couple of firmish taps to go in, then gingerly gave it a twist and presto! Out she came :) The top is really buggered, and while it could easily have been me I'd be surprised because I really didn't use a lot of force on it last night.

    IMG_20190724_220252.jpg

    Taking a night off from working on the bike, but had to try this to know if it'd work. Now it's time to order a new jet to replace it. Gave the sliders another push/pull and I'm convinced something is blocking them... they move easily then stop dead. Maybe a slight change because it's a later (MY97) model?
     
  7. Jethalter

    Jethalter Active Member Premium Member

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    Its a neat trick that works well on most things. Especially small stuff. The heat gun on aluminum is just to make it expand so its easier to turn, usually a little bit of rust or corrosion or such in the threads is enough to make it a bit difficult to turn, but once started, comes out like a dream.

    How far up are they going ???
    There really isn't anything that stops them moving up. If you can have a look at them from both sides of the carb and using a torch, see if there is any damage on them to stop them moving up.
    Remember the left has 2 sliders that are connected in pairs and so does the right. So they need to move up equally, otherwise if they kink one will stop the other.
     
    Last edited: Jul 24, 2019
  8. Laceysnr

    Laceysnr Member Premium Member

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    Yeah I've been trying to pull push them evenly but with the push I do wonder if it's because the pressure is on one side of the sliders (i.e. I'm pushing both, but on one edge of the cylinder top). They're coming up maybe a centimetre or so no problem, but then stop dead at the same point on both sides. I must be missing something obvious I reckon.
     
  9. Jethalter

    Jethalter Active Member Premium Member

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    Thats very odd, there is no set screw or stop screw or such to stop them. 90-98 across all the same.
     
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  10. Andych

    Andych Well-Known Member Premium Member

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    Maybe try tapping gently from below to assist the Emulsion Tubes to come out as well... the ends of the needle might be munted stopping everything coming out. The emulsion tubes knock out fairly easy but I doubt you would pull them out trying the way you are.
     
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  11. Jethalter

    Jethalter Active Member Premium Member

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    With that said above, find a long bolt with the same thread as the pilot screws to screw into the emulsion tube. That way you wont damage it with say using a punch or something.
     
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  12. Andych

    Andych Well-Known Member Premium Member

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    Yes, sorry, I was more thing a piece of wooden dowel as that is what I used to pop mine out.
    I should have mentioned that. I was in a rush to get out the door.


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  13. Laceysnr

    Laceysnr Member Premium Member

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    Will give that a whirl tonight and report back, thanks for the ongoing advice guys, hopefully I can get this thing completely cleaned up pretty soon.
     
  14. Laceysnr

    Laceysnr Member Premium Member

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    Got the bastards! I think the needles were just stuck in place with petrol residue. I added a bit more leverage with a screwdriver while pushing up with my fingertips and felt a bit of a budge, moved the screwdriver to the other slide and levered and the first lot came out. Repeated on the other side and that came out too in the end. Spent a good 30-35 minutes cleaningthe four of them.

    The stops I was feeling:

    I didn't realise the needles were on springs, so the movement I was feeling before the 'stops' was the slides pulling out to the spring's maximum extent and then stopping because the needles were suck. I've cleaned everything up and soaked the tubes with a heap of cleaner but I'm wondering if a pipe cleaner or something is the way to go? My jets have been soaking for two days and I can't see light through any of them - thinking a petrol bath next maybe? If that fails maybe I'll try and find an ultrasonic cleaner but might be easier to just replace them at this rate. I guess I need to try and get the brass washers out to clean them properly too. Have attached a bunch of before and after pics, would appreciate any input!

    Carb body before:
    carb_side_dirty.jpg dirty_tubes_crop.jpg

    Carb after a scrub:
    carb_bottom_cleaned.jpg carb_from_top.jpg

    Float needle - does this need to be replaced?
    float_needle.jpg

    The bastard needles:
    needles_dirty.jpg needles_dirty_2.jpg

    The cleaned needles:
    needles_clean.jpg
     
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  15. Andych

    Andych Well-Known Member Premium Member

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    What you need to do is go to a Repco outlet and buy a can or 2 of Threebond. Buy the petrol version.
    Find a glass container and pop all your brass items in there and spray enough to cover them and soak them for as long as it takes.
    I did mine overnight.
    If you have an Ultrasonic cleaner then pop everything in there and cook them for an hour or so in a strong mix of Vinegar, water and some laundry detergent ( not much detergent). I prefer to use some Simple Green concentrate in place of the detergent.
    Once through all that if you have compressed air give everything a good blow out and check that you can see daylight through all jets.
    Don’t try pushing anything hard through the jets as it can damage them.
    Follow all the instructions in that guide and you will be fine.

    Make sure you push out the emulsion tubes too. They do come out, some are harder than others.

    Personally, I would change the float valve and seat on both carbies.


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  16. Murdo

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

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    Are the rubber tips of the needles hard? If so replace them.
    Use some heavy fishing line or bruchcutter line to clear passages, particularly the idle circuts as these are very small and easily blocked. Give the three bond plenty of time to work. So far going well.
     
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  17. Laceysnr

    Laceysnr Member Premium Member

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    I'll hit up Repco tomorrow when I head to Bunnings to get vinegar for the tank, thanks for the ongoing assistance. Hopefully have it all going back together soon enough.
     
  18. Laceysnr

    Laceysnr Member Premium Member

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  19. Andych

    Andych Well-Known Member Premium Member

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    That will be the one.. I normally have at least 1 spare in the garage.. but I have a set of Honda CB400F carbies to do soon so I will need more lol
     
  20. Laceysnr

    Laceysnr Member Premium Member

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    Cool. Have just arranged to go and purchase an air compressor tomorrow, figure that's going to be useful for more than just the jets given that I'm a bit over pumping up tyres by hand!
     
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