16 hp tecumseh engine

[the picker]

I just bought a 6 wheel argo with a 1988 16 hp Tecumseh engine and lost the engine . I bought another used engine and put it in but I am getting motor oil in the fuel pump vacuum line. Could I use a 12 volt low pressure fuel pump to eliminate the problem?

[dirtdobber]

Welcome picker. An electric pump should work just fine as long as its pressure is low enough so that it doesn't force fill the carb.

[the picker]

But what is causing it to do that thanks

[dirtdobber]

I have to guess at the answer because I have never been into one of those, but here goes. The pumping action is caused by a pulse which is caused by a change in air pressure in the crank case as the piston goes through its travels. I guess your fuel pump is connected to the crank case via the rubber hose. So my assumption is the engine is "pushing" oil into the line. I would look at the following things:
1) Is there a crankcase vent somewhere and is it stopped up?
2) Too much oil?
3) Low compression/blowby creating excessive pressure in the crankcase, thus pushing oil into the tube?
4) Riding on very steep slopes such that oil gets poured into places that it shouldn't (not likely, but maybe)?

When oil accumulates in the line, does the fuel pump quit working?
Does the engine run and perform as it should, except for this problem?

[the picker]

I did not notice a crankcase vent on it. The oil is correct. The compression is 97 psi. The slope is not really steep and it will work with the oil in the line but not a smooth idle or easy start.

[the picker]

Also when I use the 12 volt pump , do you block the vacuum line from the base or do you leave it open?

[reichstall]

I see the comp is good you may want to do a leak down test and see if you are losing pressure to the crankcase. Also as mentioned check breather is open and muffler is free and no restriction. Also keep in mind Tecumseh parts are getting a bit harder to find. You could do a repower and proudly be better off. I do farm tractors and small engines so I have seen this before.

[the picker]

So how do you do a leak down test and when you say repower , what do you mean? Also my question of blocking the vacuum line from the base when I change to a 12 volt pump, so do I plug it or not? Thanks.

[ARGOJIM]

I did not notice a crankcase vent on it. The oil is correct. The compression is 97 psi. The slope is not really steep and it will work with the oil in the line but not a smooth idle or easy start.

The machine should have a crankcase vent or breather mounted on the top of the valve cover and hooked to a tube running down the side of the head. If you go electric then yes cap/plug off the pulse line port.

[the picker]

Thanks for that info. But looking for another opinion of why I am getting oil in the pulse vacuum line.

[ARGOJIM]

Oil could be over full or if there is no breather the pressure has to go somewhere.
Is the pump mounted lower than the port and or mounted close to the port? Most have a 8-12" pulse line.
Is there gas in the oil thinning the oil out or possibly over filling it?

[dirtdobber]

You could do a repower*He means you could install a different engine.

[the picker]

The pump is about 3 inches higher than port .The oil level is good but using 10 w 30. The vacuum line is about 14 inches long. The breather is in place.

[the picker]

Thanks I thought that.

[the picker]

So is the vacuum line too long? Also any other ideas on this problem would be great.