Sorry for my English I will do my best to explain this. The carbs of this Honda Magna have a knob in the middle of the carbs. It is for idle adjust, but is the problem is bigger you have to clean the carbs, check the jets and diaphragms is better if you can use an air compressor or maybe a vacuum sincronizer.
No such thing as a magna 750 vtwin. They're a V4, and the idle adjust is a plastic thumb screw pointing down right next to the choke.
The idle for a 1986 Honda Accord is adjusted by a idle air control valve. These function by either tightening or loosening the valve. This controls how much air is allowed into the system, more air means higher idle and less means lower.
Idle on a 1985 Honda Civic is adjusted through a idle air control valve. This valve is located near the intake. Adjust the valve by either loosen or tightening it.
To adjust the idle on a 2005 Honda Civic locate the idle control valve. The IACV and is found near the intake manifold. Open the top of the valve and tighten it to lower the idle or loosen it to raise it.
If you are not able to adjust it down with the idle adjust knob you may have an airleak at the carb.
Honda Accord 1998-2002 model GEN 6 idle speed is control by internal computer. You need to bring it to the dealer to adjust this.
twist the screw under the carb
If your engine has a carburettor turn the idle adjust screw so the idle is at the proper speed. If your engine has fuel injection the ECM controls the idle.
Go to the mechanic down the blocc
It should be on the carb!
The idle speed on a 1996 Honda Civic is adjusted using an IACV. The IACV, or idle air control valve, lowers and raises the idle by either being tighten or loosen.
On my 1980 Honda CB650 there is a small knob on the right hand side (when you are sitting on the bike) should be under the fuel tank. Turn it in for higher idle and out for lower idle.