Hot mess

[sefu]

I got a hot mess going on here. Was wondering what my next step would be. I have a 78 GS1000 that I found out doesn't have the original carbs on it. Looks like someone switched them with some Kaw Mikuni carbs. Anyway they have 3#20 pilot jets and 1#15 pilot jet in it. Only number on the main jets was #117.5 and the shop didn't have any other jets so I bought 4 #107 for the mains and ordered the one #20 for the pilot jet. I put in the #107's and she idles fine. A little backfiring but seems better. Then under load she bogs at about 5000rpm and seems to not be getting enough gas. Where do I go next.

[sefu]

Oh

And another thing, when you blip the throttle, it takes some time to come back down to idle. Like you blip it and it falls back down to idle slowly.

[psyguy]

mr sefu,
before the gurus here say something meaningfull, here's my 2c
have a look at the "carbs specs" thread in the forums to see if your model is listed there but even if its not you should still get a good idea of the jetting required (if you have mikunis, even if they re not original for your bike its likely you ll find the info you need)
then theres the question of your intake/exhaust setup - stock or modified
you also have to have meticuluosly cleaned carbs with new o rings and completely sealed intake path before attending at jetting
and before all of the above, confirm the valve clearances and the engine compression
keep us posted

ps. the above is pretty much what the service manual calls for when adjusting carburettors

.

[mac1170]

gday mate, you havent quite specified whether the carbs on there now are constant velocities, or slide, original slide pilots have holes drilled in the sides, cvs, have no holes, 117.5 is around the mark for the orig main, setting, pilots seem to be slide numbers but obviously some one has mixed up a jet, if u have 3 @ 1 size, as u do not have mixed pilot jets. some suzuks have mixed mains from hamamatsu, from the bogging its lean, go 120 mains, sort the pilots, needle in the middle groove,regards

[first timer]

do they look like this

http://www.sudco.com/Diagrams323728/expvm29.gif

or like the vm carbs that are shown in the carb clean up guide in the gs garage section?

[sefu]

Hot Mess

What up guys sorry for the delay haven't been at the computer for some time now. First Timer, right pic but the fuel imput is between 1&2 and 3&4 instead of 2&3 and there is no vaccum port for the gas tank at all. But that is pretty much the right carb. Especially the float bowl. with the one large drain plug and not the side drain plug that most pics have. Seems I got a lot more work to do till I can get back at you Oh. here is some pics of the carbs that I have. almost forgot.

[mac1170]

gday sefu, from your escription it sounds like a smoothbore carb, not a stock slide, as in first timers, diagram, does the slide look flat, or round,regards.

[sefu]

carbs

The slides are round.. I wish I did have some flat slides.

[mac1170]

gday mate, earlier smoothbore carbs, had round slides, look on the carb bodies, to see if there is a number, also try measuring the motor side of the carb mouth, is it 31mm, or 33mm, also is the airbox side polished, regards.

[mac1170]

gday mate, missed the picture you posted, so disregard the polished part, i have been told that suzuki brought some of the early kat1100s, out in new zealand, with a slide carb for production racing, these were called an ovalbore carb, maybe some of the kiwis, can help with this,regards.

[first timer]

the float bowl is not stock, oem has drain hoses on the bottom, but smoothies usally have 4 diffrent holes on the mouth of the carb yours only has two. best bet is to pulll them and measure the ID of the engine side carb passage. 29mm = 29smooth bore, 33mm= 33 smoothies. if yo ucan also take a picture of the of where the slide goes and show the slide all the way up too, that would help id it as well.