Other Stuck Mikuni Needle and Seat

[DAG]

What would cause a N/S get stuck into the seat? Popoff is set to 20psi; I put over 60psi in the thing and it would not pop. Had to take the pliers out of the toolbox to get them separated...

Ski ran great all during wavedaze, go to take it out for the first time after the trip and it would only fire for around 10-20 seconds before cutting out. Good compression and spark. Fuel is being pulled from the tank, did notice the jet restricted return line was plum full. I was able to dump gas down the carbs and it would fire and run fine until it ran out of joose. When it was firing I did not see any atomization during the blips which tells me there was blockage in the circuits. It appeared the fuel flow was straight from the inlet side out the return. I'll dig out the pump side tomorrow, what should I be looking for? garden gnomes?

 

[Matt_E]

Corrosion.

 

[DAG]

There was no corrosion on the diaphragm side.. I did swamp the ski twice but got it back running for a good bit afterwords. I'm curious if pressure pushed or sucked the needle into the seat; if it was caused by excess fuel or air.

 

[Matt_E]

There are only two reasons I've ever seen: a marred needle body or seat sleeve (not likely if it was working fine before), OR some corrosion.

 

[SXIPro]

I had one that would stick because the little rocker arm doohicky had a wear spot/divot on it from where the needle kept whacking it. I didn't have an extra rocker arm doohickey so I just sanded out the burr. Been working for 2 years now like that.

 

[Big Kahuna]

gummed up residue.

 

[QuickMick]

Sometimes sitting for a while and the rubber needle actually dryies out sticking to the seat.

 

[Big Kahuna]

Sometimes sitting for a while and the rubber needle actually dryies out sticking to the seat.

hense the reason they say to lube the needle when doing a popoff test.

 

[DAG]

gummed up residue.

There was some gumd residue around the 4 post which center the needle... but... not enough to make it take as much pressure as it did to pry them apart. After it was freed it was poping at 20psi just fine.