Super Jet 93 superjet carb issues

[superjetslayer7171]

Absolutely no fuel is going into the carbs. I just rebuilt it with all new gaskets, springs, filter and diaphram. What are some solutions to get it to send fuel again.?

 

[Midlake Crisis]

I am only saying this b/c I have seen it done - please do not ask by who - but make sure the fuel supply enters the bottom fitting and the return goes out the top fitting. Ahem.

 

[superjetslayer7171]

I took off the carb and found that I don't have any suction at the intake. The spark plugs always have a lot of fuel on them. The top compression is good and the engine is trying to start. Would this mean that the reeds are bad?? Or would it be something else such as a seal or something internal in the engine?

 

[Matt_E]

If there is zero negative (relative) pressure in the intake runners as you crank the engine ('no suction', as you put it), that means there is a giant hole somewhere in the bottom end. If you're lucky, it's the crank seals.

 

[superjetslayer7171]

Can you check the vacuum with the reed cage off or does it have to be there to get suction? Could it still be the crank seals even if it sounds like its about to start. Do you have to disassemble the entire engine to get to the crank seals?

 

[Matt_E]

Reeds not needed to check intake pressure.
You do need to remove the flywheel and PTO coupler from the crank, remove the stator from the cases, and split the cases to replace seals.

 

[superjetslayer7171]

So if there is zero vacuum, is that the most likely issue? Is it an easy job or is it better to take it to a shop?

 

[Matt_E]

Put your hand over the intake manifold hole that the carb normally sits on. Hit the start button.
If you don't feel suction on your hands, there is a big issue. I don't think crank seals are likely as they would have to be literally missing altogether for a complete lack of suction and the left and right case sides are pretty well isolated from each other so you would be missing seals from both ends).
A hole in the cases is more likely but not that common. Verify the suction part before getting too worried.

 

[superjetslayer7171]

What does it mean if the air is blowing back at me?

 

[550headache]

reeds

 

[superjetslayer7171]

Thanks!

reeds

Thanks! Thats what I was hoping it was.