Rebuilt 425 engine and still having problems

[FarmerGene]

Well I rebuilt the ole fd620d and she ran good for about an hour. now she has a surge but it seams to only be at lower rpm's. higher rpms it smooths out but it still sounds a little bogged down like its running rich. the plugs are burning perfectly and she does not blow any color smoke. thus far I have.................
1.checked the compression both cylinders-held 170 psi for at least 10 sec.
2.checked valve clearance- .010" on all four.
3.checked both coils per tm 1517- both in spec.
4.checked both plugs for good spark-both good spark.
5.had carb off about 6 times and she is clean, also needle and seat look good.
6.checked the delay module for voltage on all wires (except ground) all good.
One thing that struck me as strange though is my fuel filter. I closed the shutoff valve before the fuel filter to rip the carb off for the 10,000th time and it drained completely empty. Well I put it back together and opened the fuel valve getting her ready to fire up. well when I turned the key to the on position (not crank position) the fuel pump makes noise but the fuel filter which has a clear housing never filled up with fuel? is that right? also i think i had a small amount of fuel in my crank case when I drained it but i cant say %100 for sure. please help

 

[will v]

Fuel in the crankcase - as in mixed with the OIL? Or do you mean in the cylinders?

One other thing to check is the throttle linkeage. I just rebuilt my 445 motor (same as yours but fuel injected) and the trickiest part was getting the throttle adjusted in line with the arm that runs in to the block (not sure what it's called).

I was told by my dealer when reassembling that the arm should be full clockwise when the throttle is 100% open. This was the case on the 445 setup and I am assuming the same on the 425.

If this isn't making sense I can explain in more detail.

Will

 

[FarmerGene]

Fuel in the crankcase - as in mixed with the OIL? Or do you mean in the cylinders?

One other thing to check is the throttle linkeage. I just rebuilt my 445 motor (same as yours but fuel injected) and the trickiest part was getting the throttle adjusted in line with the arm that runs in to the block (not sure what it's called).

I was told by my dealer when reassembling that the arm should be full clockwise when the throttle is 100% open. This was the case on the 445 setup and I am assuming the same on the 425.

If this isn't making sense I can explain in more detail.

Will

After riping apart the carburetor bunch of times(got pretty good at it) I fond a small restriction in the jets, after cleaning the tractor runs fine :thumbsup: Thanks for the follow-up

 

[parrott]

AM128906 MODULE 1 X TIME DELAY, have you looked at this module it is noted for going bad. Mine acted up when first started it would go thru a coughing and spitting for the first 15 minutes than it would clear. This relay allows the engine to run for a couple of seconds before closing the fuel shutoff. Also opens when its suppose to on start up.