1993 Seca II 600: up and down idle. very cold blooded

OK, I bought a 93 Seca II yesterday. It has 31k Miles and the following has been done/replaced:
New: Brakes, Tires, Chain, Sprockets, battery, fork seals, clutch and cable, oil changed and tuned up.
Rebuilt: Front and back master cylinders, fuel pump and carbs.

When starting on full choke it fires right up and hovers around 3500rpm. After a couple minutes I push the choke in and it dies. 5 minutes on full choke, dies. 10 minutes and some throttle work and she'll run.
How can I choke it for just a couple minutes and have it idle peacefully at 1000rpm and be ready to ride.

Also, when i'm riding and stop at a light it idles at 2.2k rpm and after 15-20 seconds it comes down to 1100. Any ideas there?

Finally, if i don't rev it to 3500 rpm it will die in first gear.

Any help will be very much appreciated..

 

You'll at a minimum, need to sync your carbs. All of your symptoms point to a bad sync.

HOWEVER, given that you just bought the bike, and the carbs haven't been cleaned, you might need to clean them and adjust the pilot mixture screws too. A bad mixture will through off your sync too.

What are the valve inspection/adjustment intervals like on the seca 2's?

 

Textbook sucking air, sounds like.

 

Well, I'd like to try and synch the carbs myself. They guy I bought it from said they were cleaned/rebuilt and i'd like to avoid doing that if possible. Anybody have a good synch technique? Manometer? homemade Manometer? I've read up on the BB test...Someone said they just blow in the carbs, whatever that means...

just need a good test that can be done at home by a guy who's not a mechanic, but who has taken of and cleaned float bowls in an apartment complext parking lot with success.

 

You can build a 4-tube manometer with some PVC tubing, 3 or 4 way "T"s and some ATF. Search this site (I posted a list of materials and a how-to, as have others). Syncing is easy, just hook your manometer up to the ports on the intake, start the engine, set the idle at spec rpm, and adjust the sync screws until the vacuum across each of the ports is level. If your rpms change as you get closer, bump the idle back down to spec. Syncing has no value above idle.

Realize that just because the PO said they were rebuilt, doesn't mean they were, or that it was done well. For most of us on this site, the only to avoid rebuilding a set of carbs is to sell the bike as soon as it has problems :roll:

Seriously though, if the carbs require any cleaning/rebuilding, there just won't be any way around it. Start off with the sync first, check for air leaks as jeffcoslacker mentioned, but if that fails, you can assume that the carbs need work. Carb cleaning/rebuilding is a tedious job, but is not hard, and I'd reckon most members on this site (me included) learned from How-Tos on this site with no previous experience.

Also, consider buying a service manual to keep your bike properly maintained.

 

Seriously, then--

START OFF by checking and adjusting the valve clearances.

THEN worry about trying to sync; assuming the float levels wet-verify as being correct.

Homemade manometers have many varied forms and degrees of success. Good luck, if one idea doesn't work try another.

And don't "consider" buying a service manual. BUY a SERVICE MANUAL. You're going to need it.