Engine starts fine and then Bogs down?

[StrontiumEthics]

On one of my engines I have a problem that is driving me crazy. The engine bogs down and does not reach its highest RPMs. After a long trip around town it started to act funny last week. Here are the 2 possibilities that came to mind.
Electrical system, and fuel system. I started off by opening the carb and looking inside to see what was going on. I thought maybe the float might be to high so I slightly bent the wishbone arm downward. Then I started her back up It started off fine but after about 25 secs of riding engine began to bog down. Then I changed the carb and the same thing happened. THen I tested the coil with a multimeter and it read 358 ohms. I switched the spark plugs. But something that I found particularly interesting is that the spark plugs were really rich when I removed them, and the needle is at its highest notch. Even more strange was that this never happened before and I rode my bike ALOT. Right now i am bout to go test the CDI, and take a look at the sparkplug again. If there are any suggestions please feel free to assist! Thank you.

 

[GearNut]

Have you recently changed your oil to gas ratio to a higher one? That would make the air:fuel ratio richer. (IE 20:1 changed to 32:1)
A dirty air cleaner will too, but I figure that you all ready would have thought of that yourself, same with a loose and falling choke.
A partially plugged up muffler can do it as well.

 

[StrontiumEthics]

Have you recently changed your oil to gas ratio to a higher one? That would make the air:fuel ratio richer. (IE 20:1 changed to 32:1)
A dirty air cleaner will too, but I figure that you all ready would have thought of that yourself, same with a loose and falling choke.
A partially plugged up muffler can do it as well.

Wow Gearnut! Its like your a magician. I actually did change from 20:1 to 32:1 cleaned my air filter and adjusted the choke. But I did this before the problem happened. Today after making some time I managed to find out the problem. The problem was indeed electrical related. I believe that the CDI went bad somehow because when I changed it, and the muffler, the bike ran just the way she should. All the time I was doing test rides fuel actually dripped out the muffler. It had to be either the fuel was to much for the engine or the engine wasn't burning it. If I changed the carb the it must be that the engine wasn't burning it! Thank you for the help. = ) What are some problems that you have had with these little gremlins before?

 

[motorpsycho]

actually i have read several times that the gas-oil ratio does not affect the air-fuel ratio...they are 2 separate things.
if your gas-oil ratio has too much oil in it, it will make it harder for the spark plug to burn the mixture and the plug will become oil fouled resulting in a bog.
this is what i read, not 100% sure if it's true or not.

 

[GearNut]

More oil mixed in the fuel raises the specific gravity of the fuel and also thickens it.

Given the same orifice, or jet size, fuel mixed at 32:1 will flow more through it than fuel mixed at 20:1.