1997 XP 787 Hard to start

[GrupaNation]

Check out the link in my signature block for the history on this machine.

So I replaced all the fuel lines, new fuel selector, new fuel filter/ O-ring, cleaned and rebuilt the carburetors with the OSD Mikuni kit, cleaned the check valves on the fuel breather, and put a new check valve on the accelerator pump. Spark plugs are basically brand new, and compression read 135PSI in both cylinders. Why will it not start up?
The only way we can get it to start is pouring some gas down the carbs. then it will run but it doesnt seem to be pulling any gas from the carbs.
The accelerator pump is just pumping air out the nozzle, it doesnt seem to fill up with gas.

 

[mikidymac]

You either aren't getting fuel to the carbs or the carbs aren't sucking fuel.

Make sure all the fuel hoses are connected to the correct ports.

Make sure you connected the pulse line from the MAG carb to the crankcase nipple.

If these check out you will have to pull the carbs and check the fuel pump side.

 

[JeremyD615]

Definitely go through your lines again and make sure the fuel filter cup is on snug. This looks and sounds like an air leak that is making it difficult for the carb to pull fuel.

I’ve had some issues lately with the fuel pump gaskets/cover not sealing well and causing similar issues. Make sure there are no creases in the diaphragm, and the bolts are snug on the cover...