Idle mixture is rich

Hi Folks,
I got my '82-750 Seca running good, the bike is a screamer, but I still have some carb work to do.
When I start it up, I can not add the slightest bit of choke, or the cylinders flood, and the plugs foul up.
Any idea what my be going on?

 

Any more details? Is it Idling fine or fast? Could just be your idle mixture is way too rich.

Recent changes? Did this happen suddenly?

 

Engine seems to be running well, no soot on plugs, and plenty of power. Just that using choke is unnecessary, and if used will flood engine.
The carbs were overhauled by the previous owner, a competent amateur mechanic. I have to ask him if he raised the needles.

 

Interesting. I'm surprised your not sooting the plugs if you don't need choke to start it this time of year. Let us know hat you find

 

Yes please find out, I have a 650 maxim, same exact symptoms, I hardly need any chocke to start the bike, plugs are black in my case.
Just a little bit of choke and it dies.

 

If your carbs have not been modified (jets changed etc) I would be looking at tuning.

1) make sure your valves gaps are all in spec and adjust if required.
2) Warm engine and do a plug chop. Adjust and repeat as required to get rid of the soot and get close to the right brown coloring
3) Vacuum Sync the engine
4) repeat the plug chops and fine tuning

May have to do a few cycles of sync and tune. Of course this also assumes your carbs are squeaky clean and there are no air leaks. Wasting your time tuning if that is not so.

 

I had the same problem with one of my 750's The PO drilled the orfices in the float bowls out. Had to use the spare bowls I had from my spare carbs. Any choke at all and she would blow black smoke out and foul the plugs.

 

I talked to the former owner, he did a carb disassembly, dip and cleanup, floats set to stock, then set the mixture screws 2 1/2 turns out. Nothing else.
Could be some guy before him changed the jets, but who knows.
Too stormy here to do plug chops for now.