83 gs750t Just doesn't wanna go, but it used to.

[ennuii]

Good afternoon.
I have a 1983 gs750T That Was running when I got it. But running poorly.

Since then I have:
Fully cleaned the correct way the carburetors with new O rings all around (not a rebuild kit)
Replaced Spark plugs,
vacuum synched carbs
rebuilt front forks with new seals.
new air filter in stock box.
stock exhaust

Then I took it for a ride for about 5 miles, and everything was great! No problems after getting the idle spinny knob under the carbs in the right spot.

no leaks now!

Now, after 3 or so days of rain I went to ride to work this morning because it's so nice out and it didn't want to go.
Turned it over, and wouldn't run off choke now. Kind of got it running, even though it sounded like the engine was blubblubblubbing slower and got to the end of the driveway and it stalled as soon as I stopped.

Anyone have a suggestion?
What am I missing?

It's gotta be something stupid and simple.

 

[tom203]

I'll assume your tank is seasonably clean and you have enough fresh gas in it. Have you checked your petcock for correct operation?
What was problem with idle stop screw-was it erratic on that first ride. Do you remember how far out your idle air mixture screws are?

 

[ennuii]

Tank's clean, fresh gas.
petcock is on, it really doesn't like to turn at all without vice grips attached. But it's clear and the screen is clean as well. (was cleaned out as well when doing the carbs.) I do plan on replacing it and new gaskets as well. Should it be on on, pri, or res? I haven't changed it since going for the first ride. I am reasonably certain it is on res atm, and changing it to one of the other position doesn't change the symptoms.

The idle screw was in all the way so I couldn't get it to idle before. I didn't really know what it did. Adjusting it a bit when taking the choke off on the initial ride made it go, didn't work this time.

I believe the screws are at 2.5x turns out.

 

[81ZUKI75]

So, what were you doing with the choke?

 

[ennuii]

It's wide open to start. Otherwise it won't start.
it starts up and hops up to high rpm. Like 5k. I back it off to about 1/3 and it'll idle at what it's supposed to.

Backing it off more kills the motor.

 

[81ZUKI75]

It's wide open to start. Otherwise it won't start.
it starts up and hops up to high rpm. Like 5k. I back it off to about 1/3 and it'll idle at what it's supposed to.

Backing it off more kills the motor.

This sounds pretty normal for a cold start.

Was the engine fully warmed up when you got the "idle spinny knob under the carbs in the right spot"?

 

[ennuii]

Yes.

sorry to bikes I'm a f.n.g. is that wrong?

 

[tom203]

Something is amiss here! You cleaned carbs (full strip and dip??) so idle circuit passages should be able to supply mixture sitting on idle stop screw with " choke" off. Is idle stop screw bracket secure?
i'm having trouble understanding how you could vacuum sync these things if....

"The idle screw was in all the way so I couldn't get it to idle before. I didn't really know what it did. Adjusting it a bit when taking the choke off on the initial ride made it go, didn't work this time."

Sometimes it takes two goes to get carb passages thoroughly clean - without clean idle passages the carbs can't deliver enough mixture to keep engine running when enrichment system is off

 

[ennuii]

Full strip and dip yes. Each carb and all parts non plastic were 24 hours at least in berrymans.

It wasn't ratcheted down, just too far in to do anything. The first time I

Are you supposed to run on choke for a while or something? About how long If so? Watch this be user error... story of my life as an IT.

 

[tom203]

I start mine on full choke, quickly drop choke to about 1/3 so rpms don't soar. Take off in 20 seconds, drive up driveway ,turn on side road, get to main road, pull out and immediately turn off "choke". So choke is on for maybe 2 minutes total.

 

[81ZUKI75]

Full strip and dip yes. Each carb and all parts non plastic were 24 hours at least in berrymans.

It wasn't ratcheted down, just too far in to do anything. The first time I

Are you supposed to run on choke for a while or something? About how long If so? Watch this be user error... story of my life as an IT.

+1 on tom203's comments.

I run three different carb'd Suzukis and they all respond a little differently to the choke. "MY" 750T prefers a little throttle to cold-start in the spring/summer (which effectively bypasses the enrichment /choke circuit) but then requires a little choke/or throttle to stay running for a few minutes to warm up. My 750E always takes a little choke on a cold-start. My Bandit really doesn't like to be choked once the spring thaw comes around. The old Suzuki's do take a few minutes to warm up.

 

[ennuii]

So. User error.

I didn't know to run it on choke for a minute or seven to get it going. Good to know!
Once it goes for a bit it'll idle and start up and get goin' all by itself without the choke.

Thanks for the assist forumites!

 

[ennuii]

Took it out on a ride. Everything went well for the first half. I put 30 miles or so on it. Riding to see the wife at work and back for lunch.
The first half after riding with the choke open for a minute went well. But on the way back when coming to a stop or pulling the clutch all the way in would immediately kill the bike (totally not the safest thing ever). I thought that was kinda odd.
If I coast to a stop and didn't have the choke open at least 1/4 the way it would stall out and just die, but start right up with a little choke open.

Is this a normal symptom of something?
Anyone have any ideas?

Thanks!

 

[tom203]

When bike is warmed up, you need to adjust idle stop screw so that idle won't drop below about 1100 rpms. When cold it will likely fall to maybe 900 if "choke" is fully off.

 

[ennuii]

Thanks!

this forum is great for newbs. I learn so many neet things.