questions after carbs rebuilt

[skitter]

1985 suzuki gs 750
so before i take my carbs back i would like to ask a few questions , i had them cleaned / inspected , finally got them back on the bike now it wont start .. it seems there getting fuel , well deffiently the 2 middle carbs are getting fuel , and then they overflow into the outer carbs it seems , but still no start , have spark obviously i only pulled to fix a few idle issues which i was told was wrong with the carbs anyhow , now i know that they set the screws on top (fuel / mix screw ? ) but im thinking maybe they did it wrong i cant find anything on the manual it just says 'pre set' , anyhow if anyone has a suggestions that'd be great , i know the carbs are sucking the fuel out of the tank fine and there getting fuel .. it just doesn't want to fire now which leads me to believe something is set wrong... thanks !

[GateKeeper]

are you getting spark ?

[skitter]

yes spark on all four

[skitter]

iignition is all new and works fine ive checked twice , it has something to do with the carbs

[tom203]

Doublecheck plug wires on right plugs- but sounds like "they" made a mess of things when carbs were fiddled with- no start, overflowing carbs, etc. It's really best to learn to do this work yourself .

[pearljam724]

1985 suzuki gs 750
so before i take my carbs back i would like to ask a few questions , i had them cleaned / inspected , finally got them back on the bike now it wont start .. it seems there getting fuel , well deffiently the 2 middle carbs are getting fuel , and then they overflow into the outer carbs it seems , but still no start , have spark obviously i only pulled to fix a few idle issues which i was told was wrong with the carbs anyhow , now i know that they set the screws on top (fuel / mix screw ? ) but im thinking maybe they did it wrong i cant find anything on the manual it just says 'pre set' , anyhow if anyone has a suggestions that'd be great , i know the carbs are sucking the fuel out of the tank fine and there getting fuel .. it just doesn't want to fire now which leads me to believe something is set wrong... thanks !

Sounds to me, you flooded the carbs. By most likely leaving the petcock on prime for too long. That or you have the incorrect hose hooked up to the petcock. Could have a breather hose hooked up to the petcock. Rather than a vacuum hose. But, if you have fuel in the bowls by priming them it should at least start and run with choke open. Until it runs out of gas in bowls or you shut the choke off. See if the bowls are getting fuel by cracking the drain plug.

[althomas101]

I'm not seeing a 1985 GS750, just a 85 GS700 on bikecliff's chart http://members.dslextreme.com/users/...specs_v1.3.jpg . Anyway I just rebuilt my GS1000 which has the old smoothbore VM carbs on it I used 1 1/4 turns out on the fuel screw and 2 turns out on the air screw as a starting point. The bike fired up no problem although I had to back the air screws in to 1 turn out as it was popping pretty bad. Anyway it seems like 1-2 turns out on both will get you in the ball park so you can get it started. After that you'll just have to tinker to get the mixture right. I hope that helps.

[Steve]

Anyway it seems like 1-2 turns out on both will get you in the ball park so you can get it started. After that you'll just have to tinker to get the mixture right. I hope that helps.

If he does have an '85, it won't have the same carbs you do, so those settings are useless.


Skitter, where are you? Someone might be close enough to stop by and lend a hand.

Who knows? As much as I travel, it might even be me that's "close enough".

.

[althomas101]

I know that the settings for my VM carbs would be different than his BS carbs, however in my search of this forum and elsewhere it seems that Mikuni carbs come from the factory with between no less than 1 turn out and no more than 3 turns out. This also jibes with my experience on Kehin carbs. On Hondas you can basically just set them all to 3 turns out, no more than 3 1/2 or the fuel screw will vibrate loose, because the spring doesn't have enough pressure. He just needs to get in the ball park so that the bike will start. once it is running he can fiddle with it to figure out what it really needs. If I were him I'd just set both screws to 2 turns out, I'd be willing to bet money the bike would fire.

[skitter]

thanks for the replies turns out they were quite out (the screws) , did them 1 1/2 turns and it fired .. its still rough tho.. i mean starts fine , idle fine , revs fine but in gear seems like its not exceeding its power limit? like very slow ? like its not hitting powerband i guess .. just gutless maybe i have another problem was hopeing the rebuilt carbs would have helped or do i need to tinker with the screws again , and im located on vancouver island ) (bc ;p

[pearljam724]

thanks for the replies turns out they were quite out (the screws) , did them 1 1/2 turns and it fired .. its still rough tho.. i mean starts fine , idle fine , revs fine but in gear seems like its not exceeding its power limit? like very slow ? like its not hitting powerband i guess .. just gutless maybe i have another problem was hopeing the rebuilt carbs would have helped or do i need to tinker with the screws again , and im located on vancouver island ) (bc ;p

You have a vacuum leak.