GUIDE: Fitting new seals to your GK76a Carbs!
Posted: Wed Jun 08, 2011 11:37 pm
Right then, I'm all done fiddling with my carbs, one of mine needed a DAM good clean out after some piston/valve got inside, but I'm there at last, and with the help of people here did it all myself! I took photos through out in the hope of putting together a guide for other first timers out there taking this on!
Firstly set yourself up a little work area equipped with a phillips & 2 flat head screwdrivers (one mid size, one very small) a 4mm allen key, some rubber gloves, a small pot of petrol (for lube) and your O-rings


Then its time to crack on!
Remove the float assembly cover like so

You'll now find yourself faced with 3 O-rings to change (only two are under the cover, but all 3 are on this face)
3 O-ring positions shown here circled in red

Starting with the bottom one, make sure your screwdriver is a good fit in that little screw, I found them all to be bloody tight, so they'll need some weight on them to crack them off! once undone, pull the float assembly out and there is O-ring one! remove, lube replace and re-assemble! Simples

Next up is the middle one in the circled picture! VERY simple one here, get your flat screw driver in the slot and undo I found this pulls both parts out the carb instead of fiddling to get a spanner on there!
once again remove, lube, replace more lube and refit!
If the centre bit only comes out like below, get the spanner out and remove the rest! the o-ring is on the jet carrier, not the jet itself

next we do the top one, undoubtedly the most fiddly and one that got me most confused
get your little flat head in there and undo the screw, it will come all the way out, and more than likely have no o-ring on the end, there will also be a spring and washer inside that little hole, so gently fish them out too with a small screwdriver or something fine!

Thats the order they go back in, I found it easier to rebuild the screw assembly lube then re-fit like so

Screw that all the way in (dont forget your lube) then when it tightens up, make sure you then turn it back 1.5 turns!
Now bolt back on the cover and job done on that side!
flip the carbs over to the black plastic tops and undo both screws but watch out because there is a spring inside! take the cap off and check that the diapragm isn't torn or broken and as long as everything is good just change the o-ring next to one of the cap-bolt holes like so

then screw the cap back on being careful not to catch the diapragm in doing so and voila, that is pretty much your lot!
If anyone wants to add anything here (especially emulsion tube o-rings) please feel free or give opinions or advice!
Hope this is of help to some people :D
Firstly set yourself up a little work area equipped with a phillips & 2 flat head screwdrivers (one mid size, one very small) a 4mm allen key, some rubber gloves, a small pot of petrol (for lube) and your O-rings


Then its time to crack on!
Remove the float assembly cover like so

You'll now find yourself faced with 3 O-rings to change (only two are under the cover, but all 3 are on this face)
3 O-ring positions shown here circled in red

Starting with the bottom one, make sure your screwdriver is a good fit in that little screw, I found them all to be bloody tight, so they'll need some weight on them to crack them off! once undone, pull the float assembly out and there is O-ring one! remove, lube replace and re-assemble! Simples

Next up is the middle one in the circled picture! VERY simple one here, get your flat screw driver in the slot and undo I found this pulls both parts out the carb instead of fiddling to get a spanner on there!
once again remove, lube, replace more lube and refit!
If the centre bit only comes out like below, get the spanner out and remove the rest! the o-ring is on the jet carrier, not the jet itself

next we do the top one, undoubtedly the most fiddly and one that got me most confused
get your little flat head in there and undo the screw, it will come all the way out, and more than likely have no o-ring on the end, there will also be a spring and washer inside that little hole, so gently fish them out too with a small screwdriver or something fine!

Thats the order they go back in, I found it easier to rebuild the screw assembly lube then re-fit like so

Screw that all the way in (dont forget your lube) then when it tightens up, make sure you then turn it back 1.5 turns!
Now bolt back on the cover and job done on that side!
flip the carbs over to the black plastic tops and undo both screws but watch out because there is a spring inside! take the cap off and check that the diapragm isn't torn or broken and as long as everything is good just change the o-ring next to one of the cap-bolt holes like so

then screw the cap back on being careful not to catch the diapragm in doing so and voila, that is pretty much your lot!
If anyone wants to add anything here (especially emulsion tube o-rings) please feel free or give opinions or advice!
Hope this is of help to some people :D