I have a 18 hp Vanguard Engine on my truckmount. The engine starts and runs good with the choke slightly closed. If you pull the chock completely out the engine pulsates. When i turn on the pressure pump the engine slowly chocks out and stalls with a backfire. Does this sound like my carbs are flooding? Could there be something else causing this? Machine is a ProChem Oil Fired.
Vanguard Engine Issues
- Thread starter Don336
- Start date
Desk Jockey
Member
Do you mean the speed control not the choke? If you really mean the choke, then it is doing its thing just leave it closed.
How many hours on the power plant?
How many hours on the power plant?
Desk Jockey
Member
How many hours on the engine? Have you ever had the heads cleaned?
Desk Jockey
Member
Have you ruled out fuel filter, valves, a bad head gasket?
I haven't had air cooled for decades but back when we did one of the things that would happen when a unit had some hours on it is the carbon would build up and need to be cleaned. That could be a possibility as well.
I haven't had air cooled for decades but back when we did one of the things that would happen when a unit had some hours on it is the carbon would build up and need to be cleaned. That could be a possibility as well.
dgardner
Moderator
My first thought would be fuel filter as well. It'll flow enough to run with no load, but not enough under load (which requires more fuel).
Haven't ruled out any of the above. I'll check on those this weekend before taking it to a mechanic. Hopefully its just the fuel filter! How do you check for a bad head gasket on a air cooler motor?
Would the bad fuel filter make it had for the engine to restart after the stall?
dgardner
Moderator
It could. After running the float bowl dry it would take some time for it to refill, especially if the flow was restricted. the engine wouldn't want to restart for a while....
Charlie Lyman
Supportive Member
I'd go with head gasket problem. If it's loosing compression that could cause the issues. Hopefully it's not warped. Might set aside money for a new engine.
Charlie Lyman
Supportive Member
You should have the new head gasket in hand before taking the head off. Once removed you will be able to tell if it's bad.
hogjowl
Idiot™
I've had several of those engines over the years, and you are probably screwed. However, the valves on those things have to be adjusted every 200 hours or you'll have issues. So, check the valve adjustment. When that doesn't work, think long and hard before putting a head gasket on or doing any other expensive work.
Because they're a POS to begin with.
IMHO
Because they're a POS to begin with.
IMHO
dgardner
Moderator
Does it do the same if you cover the vac inlet?
Desk Jockey
Member
That will probably kill putting it under a load.
Desk Jockey
Member
Those are kind of a throw away motor aren't they? or is a short block worth looking into?
dgardner
Moderator
I agree. He mentioned that when he engaged the pump (presumably adding load) it killed it. If covering the vac inlet does the same it still points to the motor. It would be odd, but just ruling out a pump that is freezing up and bogging down the motor....
I tried to fuel filter and that didn't work. But I did notice that it's not bogging down. When I hit the switch for the pump it just kills this engine. It's acting like the switch for the cat pump is working as a kill switch. I let if run and blocked of the vac inlet and gauge goes up to 15 with no issue. Once I hit to pump switch it's like I just turned the ignition off. Any thought? Could I have a short?
Lee Stockwell
FOJL
yes
Lee Stockwell
FOJL
While the machine is shut off screw a short 1/4-20 bolt into the hole on the front of the clutch to lock it ON.
Now start the machine without turning on the pump switch. If it runs smoothly, and the pump is turning, you have a wiring problem.
Now start the machine without turning on the pump switch. If it runs smoothly, and the pump is turning, you have a wiring problem.
hogjowl
Idiot™
Did you mean without turning OFF the pump switch, or am I missing something?
dgardner
Moderator
No - he means on. Could be an electrical problem, or mechanical (pump is frozen and won't turn). If Don locks the clutch with a bolt it will turn even if the pump switch is off. Lee is trying to get the pump to turn without using the electrical (switch). If it turns thus we know the pump isn't frozen up, and that leaves electrical as the only thing left. Good plan.
Lee Stockwell
FOJL
Off first. See what happens.
Then ON. See what happens.
Then ON. See what happens.
Lee Stockwell
FOJL
If you look at the swing arms across the face of the clutch you will see a little hole and the arm is notched around it a bit. The hole is threaded. Put the little bolt into it and it will lock the pulley to the pump so that it doesn't free wheel.
No one thinks their clutch has one. They all do.
No one thinks their clutch has one. They all do.
Lee Stockwell
FOJL
Lee Stockwell
FOJL
Dan Gardner's image and notation for another issue, so ignore the red arrow. You need to thread the bolt into a hole on the front clutch plate into the threaded hole on the front pulley.
dgardner
Moderator
These Lee?
