[tarzanapoop]

I have a rich issue with my GL1220A, all 4 spark plugs are black after 4 miles on new plugs. Starts up fine, don't need to choke to start cold.Pulled carbs, cleaned out,new needle/seats,
set float level to specs, air filter new, air box intake screens are clean,it's a project bike that hadn't run in years so I never had it run correctly, had drained and refilled fuel tank that had no varnish despite being old gas. Choke cable is working and all 4 start valves move smoothly. What is the purpose of the secondary air supply system and could a malfunction result in a rich mixture?

 

[DaveO430]

Sounds like either the float level is too high or has the wrong low speed jets or plugged idle air circuits. The secondary air system has nothing to do with the fuel mixture, it allows air into the exhaust for emission control.

 

[tarzanapoop]

The floats were too high when I opened them but I set them to specs.... I had the impression that someone had been in them before, your other suggestions make sense, and I guessed the secondary system was a PCV or some other emission related function but I had to ask, thanks

 

[Bike...and Dennis]

It's pretty tricky to set the floats in those things. What method did you use?
Also, if someone has been in there before, could they have changed the jets?

 

[tarzanapoop]

With float bowl removed and carb upside down, measured the heel of the float to the the carb flange, adjusted by bending the brass tab which the needle hangs from, I set them to spec, I don't remember the actual number but they were all a couple millimeters high and all by the same amount. It's very possible that something else has been changed but I will have to pull the carbs back out to check.

 

[AZgl1800]

With float bowl removed and carb upside down, measured the heel of the float to the the carb flange, adjusted by bending the brass tab which the needle hangs from, I set them to spec, I don't remember the actual number but they were all a couple millimeters high and all by the same amount. It's very possible that something else has been changed but I will have to pull the carbs back out to check.

someone correct me if I am wrong, but I thought the carbs needs to be vertical and the float just barely touching the needle with the specified measurement?

 

[Bike...and Dennis]

You are correct John. And it's critical.
But not completely vertical, maybe 50° or so.
From the OEM Manual:

And check the manual. Some years are different than the 7.5 spec.

 

[DaveO430]

Setting the floats with the carbs upside down would result in a lean mixture, not rich.