I have a 2001 /1600. Recently I had some backfire issues and decided to clean out the carb. I found a lot of oil in the carb from the vent tube spitting back over the years. I pulled the carb completely apart and cleaned it in a chem bath. I put it back together with new jets and now it will only start and run for a little while when the choke is pulled out (engaged) all the way.
Any ideas? I saw a few posts that said never remove the throttle sensor..... I did.

and I saw a few posts that said never remove the throttle sensor..... I did. Not a good thing to do. The more knowledgeable members on carbs will be on shortly.

greyphart

jahafd wrote:
I have a 2001 /1600. Recently I had some backfire issues and decided to clean out the carb. I found a lot of oil in the carb from the vent tube spitting back over the years. I pulled the carb completely apart and cleaned it in a chem bath. I put it back together with new jets and now it will only start and run for a little while when the choke is pulled out (engaged) all the way.
Any ideas? I saw a few posts that said never remove the throttle sensor..... I did.

Its not a problem to remove the throttle sensor, just requires that it be set back using Yamaha recommended procedures when re-attached. Most will recommend against it because the re-attachment requires knowing how to use a VOM to calibrate it.

But that would not cause the problem you are talking about. The tps only has one job, it switches the ignitor (ignition) from advanced timing curve to retarted timing curve under moderate to high acceleration. Neither curve would cause this problem.

It sounds like something got messed up. Their are quite a few pinholes in the throat of the carb, on the bottom under the valve, that need to be clear for the pilot circuit to operate properly. There is also a air duct going to the front of the carb that feeds the pilot. Then of course the pilot jet needs to be clear. The fuel provided by the enriching (choke) circuit does not come through the pilot jet, so if the jet is not sufficiently clear choking it up would add additional fuel to the circuit.

Just some food for thought.

Hang in there. Also make sure you don't have any leaks in the passing enricher (the white plastic cap on the left side).

Gram

I did think of a clogged pin hole. I dont think that is it however. I used air to blow the lines clear and they all seem to be free of a clog. I have assembled and disassembled several times to check for leaks???

Did you check the float level before re-assembly? Those things are easy to get out of adjustment. (Don't ask me how I know.) Also, you said you replaced the jets. Were they of the same size? If not, what size? Can you see the black plastic slide moving up & down freely when you open the throttle.

I am going to check the float level today. I was doing some reading about that. Good stuff about the float levels but no info on how to change the level if they are out of speck.The plastic slide dosent move much because if i give it any gas it stalls.

I did replace the idle jet with the stock part. The main jet was fine.

I checked my float settings. They are 5mm at the rear of the carb with water and the float is compressed at 9mm when the flow stops. could this be the problem? I didnt find any leaks....