Not getting gas to carb on 444

[jschro]

Hi, I'm having problems getting my 444 started. It has the JLO 252 engine and Tillotson carburetor (marked as HR2A). Gas tank and gas line are good, carb has been disassembled/cleaned/rebuilt multiple times (most recently by a snowmobile shop) so it should be good, and I have good spark at the spark plug. If I dump a little gas down the carb the engine will fire up and run for a few seconds but it won't pull gas to the carb. Any advice on what to look for, or what to try next?

Thanks,
Jim

[Barrie2777]

The needle is either stuck to the seat or there is too much spring tension holding it closed or both (good luck). Carb kits often come with springs of different tensions however they fail to include instructions as to the strength of each spring based on their color (silver gold red or green).i do it by feel and guess. Choose a weak spring. The lever arm for the needle should be even with the base of the carb.(another detail which affects spring strength)

[Barrie2777]

The first and simplest is to check for a stuck needle. Take the carb apart but no need to separate all the layers just take it off as a block. Loosen the screw which holds the pivot rod and remove the arm and spring. With fine needle nose pliers pull out the needle. It should come out without resistance. If it feels at all like you have to pull then it was stuck. If you want to flip the seat over this would be a good time.

[Barrie2777]

If your gas cap is not vented it may also prevent startup although i think it should start but eventually stall when the vacuum created in the tank is more than the carb can pull.

[myoldhus-ski]

Make sure you are getting gas to the carb. pull the line off the carb and make sure gas is getting that far. Perhaps the shut off valve on the tank is closed or blocked. Good luck Jim

[snocatpete]

In addition to what Barrie has mentioned, another possible problem to check is the fuel pump pulse passage. Check for blockage and or leaking (venting) to atmosphere? Because if there is a problem anywhere along this passage the fuel pump will NOT operate. Just something else to consider and check...

[Barrie2777]

With any problem i always start with the simplest thing first and work my way up to a complete engine overhaul (ha). In this case i would work in this order
Check gas shut off valve
Gas cap
Vacuum impluse hole
Carb issues

The screen on the gas valve could also be plugged

[jschro]

Thanks for the input. I was just working on it again.
Gas shut off valve is good and functions properly.
Gas cap is vented.
I ran a small wire thru the vacuum impulse hole and it seemed to be open. Let me know if there's anything else I should do to verify the passage is clear.
Checked the carb again. The needle is free...no sticking. The shop that checked the carb for me recently put a new needle and seat in. I don't have enough experience with these carbs to know if the spring tension is correct. Seems okay, and I don't have another one to try. The lever arm is even with the base of the carb.
Same results today when pulling it over...a little gas down the carb and it fired up for a few seconds. Seems that it just isn't creating the vacuum that is needed.

[Barrie2777]

Well....if it isnt creating vacuum then it may be sucking air from where it shouldn't....blown head gasket; base gasket or go deeper by checking crank seals. The pto side is easy to see but the mag side requires some dismantling. The seal may be good but has been pushed out for whatever reason. The gasket between the cylinder and motor base blew out soon after i did my 252 rebuild beacuse the bolts were not torqued enough.

[Barrie2777]

Frist check that both intake gaskets are not leaking.