Carburetor tuning on muffs

[Toshi]

OK. I will check the line.
I am just using zip tie for the pulse line and may be I need better seal?
I just ordered snapper clamps to have better seal.

All the carbs are fed the same Fuel mix that the VRO supplies, so the only way a Cylinder by itself, would be affected, would be an Leaky Pulse/Vacuum Line between the Pump and the Crankcase.

 

[Toshi]

Good afternoon.

Here’s a movie. I am spraying 16:1 premix to the middle carb. and I kind of hear the difference, I think. So I have at least spark?

Not on this movie, but I also turned the idle screw of the middle carb and I kind of hear the difference. I don’t hear a big difference when I am doing that. Maybe it’s because top and bottom carbs are already tuned?

I am wondering if I should turn screws at NOT optimum positions intentionally for the top and bottom and start tuning with the middle carb.

Please let me know what you think.
Thank you.

 

[Toshi]

I am not sure if the movie has been up. I am trying again.

 

[saltchuckmatt]

Good afternoon.

Here’s a movie. I am spraying 16:1 premix to the middle carb. and I kind of hear the difference, I think. So I have at least spark?

Not on this movie, but I also turned the idle screw of the middle carb and I kind of hear the difference. I don’t hear a big difference when I am doing that. Maybe it’s because top and bottom carbs are already tuned?

I am wondering if I should turn screws at NOT optimum positions intentionally for the top and bottom and start tuning with the middle carb.

Please let me know what you think.
Thank you.

Where is the movie?

 

[Toshi]

Where is the movie?

Hi. It's uploaded now.

 

[racerone]

Stop running this motor.-----You have to make sure that carburetors are working properly.------If there is an issue / blockage then you risk starving a cylinder of fuel and OIL !

 

[Toshi]

I covered the air inlet (front opening) of the middle carb with my hand for a few seconds and the fuel poured out from the air inlet.
Doe that indicate I am getting fuel at the middle carb?

Stop running this motor.-----You have to make sure that carburetors are working properly.------If there is an issue / blockage then you risk starving a cylinder of fuel and OIL !

 

[Toshi]

Also, the engine started to die out when I cover the middle carb with my hand.

 

[tphoyt]

Maybe I’m crazy but it sounded like the motor smoothed out for a split second when you pulled the trigger 4 times. Even though you have fuel at the carb that does mean it’s getting through the carb. There could be internal blockage. Putting your hand over it increases vacuum and pulls in more fuel that could come from other places other than the idle circuit or even force it through a small blockage. Without the extra oxygen that fuel can’t burn causing it to want to stall.
All I can say is if it were me I would be pulling the carbs apart for a complete and proper clean and rebuild.
Best

 

[tphoyt]

Sorry “does mean it getting through” should have been “doesn’t mean it’s getting through.”

 

[racerone]

Post the compression values taken today.-----Inspect reed valves.----Take carburetor apart and post pictures of all the gaskets / parts.-----Stop running this motor until you sort out the issue.

 

[racerone]

When engine was rebuilt did you hone out the cylinder and then install a standard bore piston in #2 hole ??----We are now over 200 postings on this project / motor.

 

[Toshi]

Yes. I installed standard bore piston in #2 cylinder because the cylinder bore dimension was still within the spec.

I’m getting a lot of knowledge and experience on this project. Thank you very much for being very supportive and being extremely patient.

When engine was rebuilt did you hone out the cylinder and then install a standard bore piston in #2 hole ??----We are now over 200 postings on this project / motor.

 

[Toshi]

These are pictures of the middle carb.

All the holes, gaskets look fine to me.

Also, reed valves look fine and well seated.
No chipping or cracks.

 

[Toshi]

I will take more pictures if necessary.
Please let me know.

 

[Faztbullet]

Piston upside down?????

 

[Toshi]

It’s not.

Piston upside down?????

 

[Toshi]

Hi. Compression is 105psi for each cylinder.

Post the compression values taken today.-----Inspect reed valves.----Take carburetor apart and post pictures of all the gaskets / parts.-----Stop running this motor until you sort out the issue.

 

[racerone]

Carburetor parts all appear good in your pictures.

 

[tphoyt]

You need to remove the Welch plug as well.
There are tiny little holes under the one for the ideal needle that can get plugged up.