What do I do next

[JD Sled Fan]

Hello,
I have a JD X-8 with the 440 engine in it.
Last year I had the carb rebuilt. Then I ran it around the yard a little.
It ran well except I couldn't get a steady idle out of her. It would usually flucuate when
it was idling. In the spring I parked it. Over the summer I started it occasionally to keep the carb well lubed.
The idle would still vary even with adjustments. Then towards fall it would start,rev up,
die down,and stall. Then after a little I couldn't get it to run anymore.
Yesterday we pulled it out, and changed all the gaskets from the carb on down to under the reeds. We got it to fire up and took it for a little spin. It worked great except that
if you hit the throttle too hard when taking off it would bog down and not go. I figured
I would adjust the carb this morning, but now I can't get it to start.
What do you think is wrong with her?
She has good spark.
Seems to have good compression.
Does it need:
The base engine gasket (between crankshaft and pistons) replaced.
The carb rebuilt, even though it was done not too long ago.
Something else set on the carb.
Something else.
Thank-you very much,
Fred (on his brother Ryan's account)

[Maj_hazard]

I had the same problem last year after a carb rebuild.

In the end I found that the metering lever was incorrectly set. On the Walbros it's a fine line between the correct adjustment and to much or to little. To low and it kills your acceleration, too high and she floods or won't idle right.. I had mine apart a dozen times until I found the problem...

Other thoughts

There still may be some dirt floating around inside a passage. Nothing beats a good over-night soak for the carb.. I stole my mothers untra sonic denture cleaner and I fill it with carb cleaner and let it run for a few hours..

Is the intake manifold seal good ???

I'm assuming the engine itself is in good shape..ie compression, preasure test.

Is the gas tank clean and are you using new gas..????

Impulse line...don't forget the impulse line... Tight without kinks..Also as short as possible..

Finally nothing beats a virgin sacrific to the John Deere Gods... I had to travel all the way to Saskatoon to find mine....


Cheers

Mike

[JD Sled Fan]

Intake manifold seal is good, engine I believe is in good shape, will try to test compression this weekend. Gas is approximately 6 months old. Don't know about the tank. The plan is to take out the tank and clean it. Refill with fresh gas and install a new fuel filter. If that does no good. We will probably be back into the carburetor. Thanks everyone
Ryan

[chains1017]

Be sure to check the pulse line. It may be collapsing under stress. The idle fluctuation may be from the hose blubbering( I call it) screwing with the metering of the fuel. We dealt with this a lot on our old rupps due to excessive heat under the cowling. I usually go to the local hard ware and purchase a spring that fits snugly in the line and cut it to length, and install it. Make sure the spring cant pass through the pulse fitting, that is bad! I always hated the kehin and walboro diaphram carbs as they were finnicky this way. I assume you have checked the main seals. Doug

[chains1017]

Im back, <big><big><big>if rich sees this.</big></big></big><big><big> Was there a reason certain sleds had so much stress on the pulse lines, like under engineered to crank volume or some crap? I know the tillotson carbs seemed to be very leniant to this sort of thing. Please put some professional input into this, my da just says its just the way they were, lol. ( short for I dont care as long as the spring works) Doug</big>