Does anyone here have any idea how a 1994 Vermeer 620 fuel pump works?

ForTheArborist · Sep 20, 2010

I'm in a tight spot, and I need to get this machine back to work right away.

The fuel pump is not drawing fuel, but I took look at it, and I can't see anything wrong with it. I have to assume that the diaphram in it is faulty, but it doesn't look like it.

If someone can give me some advice to get this thing back into the action, you'd be a life saver.

Thanks

ArborquipSP · Sep 20, 2010

Is it a Kohler engine? If it is there we two styles of fuel pumps the older style is vacuum operated and the new style is part of the valve cover. The old style has a vacuum line from the back of the engine and I have seen the engine oil level overful causing it to not get the vacuum or that hose gets a hole in it.
The new style is part of the valve cover and on the under side of it there is a arm that is hooked to the diaphragm shaft. I have seen the end of that shaft wear out so the arm does not move it. Or you have a bent pushrod that operates the pump or the pump is shot.
To check the pump remove the valve cover and operate the arm underneath it and see if it pumps fuel.

Scott

ForTheArborist · Sep 20, 2010

It's an 20hp, and I believe it is a Kohler. I haven't seen the name brand on it yet.

It sound like you're saying if I drain the oil a little, it may get vacuum pressure. Is that right? Do diaphrams just up and wear holes in them? It's probably not an easy fix since the pump is tucked behind the engine.

ArborquipSP · Sep 20, 2010

If it is a V2 engine then the pump should be on the top of the left side of the engine.
There is a kohler 20hp engine that is flat 2cyl. (like a Volkswagen) it's fuel pump runs off the cam shaft and on that model I have seen the mounting screws backout and the pump comes out of the block.

The vacuum operated pump is only on the V2 engines and if the oil is overful by a quart or more it will cause that problem.

For me to help further I will need the model # off the engine.

Scott

ForTheArborist · Sep 20, 2010

I'm going to run and get that. I'll take a quick pic too.

ForTheArborist · Sep 21, 2010

It's a 94' 620BC. That's the model number. I can find any decal about the engine on the engine. BTW, the oil is overful by a lot.

ArborquipSP · Sep 21, 2010

Does the oil smell like gas? If it does the diaphragm may have a hole on it causing the gas to go into the engine not the carb. You can still pull it off and check it.

ArborquipSP · Sep 21, 2010

Or get a small electric pump from napa and wire it in to the key switch and cut the hoses that are on the old pump.

ForTheArborist · Sep 21, 2010

Thanks for the advice. I think my best bet is with the electric fuel pump from NAPA. Another thing is that there is too much oil in the thing. I drained it last night to the normal level, and tried cranking it. It still wouldn't draw fuel. I'll try it again before setting up the e. f. pump.