High screw almost in but still rich

[Old2stroke]

I m thinking if it doesn't seal around the valve or the diaphragm in the valve is stuck..

Never seen one leak around the nozzle valve and the diaphragm is supposed to be fully open for high speed operation. Have you ever checked the inlet valve pop-off pressure to make sure inlet valve isn't leaking?

 

[Stergos Rodos]

Never seen one leak around the nozzle valve and the diaphragm is supposed to be fully open for high speed operation. Have you ever checked the inlet valve pop-off pressure to make sure inlet valve isn't leaking?

Its my next job to do. Checked only blow not suck air. If it doesn't work how can i fix it? Cut an old diaphragm and put it in?

 

[Old2stroke]

Its my next job to do. Checked only blow not suck air. If it doesn't work how can i fix it? Cut an old diaphragm and put it in?

Pop-off pressure of the inlet valve, not the nozzle check valve

 

[Stergos Rodos]

Pop-off pressure of the inlet valve, not the nozzle check valve

I did, it's not leaking

 

[Vintage Engine Repairs]

Hello to everyone! I have a jonsered 670 champ. I m trying to find the reason it is running rich even with the high screw in. The saw has new meteor piston, new fuel lines, new muffler, new diaphragms. Tillotson hs series. Service manual says welch plug or nozzle valve leaking. This has not a welch plug but a main nozzle valve. I have to test if it works well and if it seals. Any suggestions ?

Worth noting if that welch plug over the idle drillings is leaking that will cause it to run rich too.

Are you at high elevations?

 

[Stergos Rodos]

Worth noting if that welch plug over the idle drillings is leaking that will cause it to run rich too.

Are you at high elevations?

I m near the sea. Maybe the welch plug is leaking but no problem at idle. Normal

 

[Vintage Engine Repairs]

I m near the sea. Maybe the welch plug is leaking but no problem at idle. Normal

Can you upload a video? It’s not the ignition limiter failing by any chance? They can start limiting at just a few thousand rpm when they do.