1650 GAS FUEL PUMP

I need to replace or repair the fuel pump on a 1650 gas tractor. Since parts are hard to find, I'm thinking about using an electric pump. Anyone know the flow rate required?

Fuel pump on a gas 1650? Never saw one.

No fuel pump on a 1650 gas unless it has had some modifications done it. Possible engine change or someone added a pump. We have a 1650 at the farm. The fuel is gravity fed from the bottom of the rectangular tank to the carb. If you put an electric fuel pump on it don't exceed 5.0 psi. The needle and seat won't hold back the higher pressures and you won't like your fuel bill. If there is a mechanical pump located on the right front side of the engine it is probably not original. Keep us posted.

I thought it was strange that the shop manual makes no mention of a fuel pump. I suppose this engine block may be used in different applications that require a pump. I'm going to return it to gravity flow before the spending money. Thanks guys.

The diesels used a fuel pump. I believe there's a plate on the gas block.

But I wonder how a 1650 gas ended up with a mechanical fuel pump. Clean the sediment bowl and install an inline filter.

I don't know about the online filter Arnie, those things tend to get hot and vapor lock.

On most Olivers that use a Waukesha engine the camshafts are the same between a gas and diesel engine, therefore the lobe is there to drive a fuel pump. Also the block has provisions for mounting a fuel pump. FWIW I put a diesel lift pump on our gas 77 pulling tractor because I could not free flow enough fuel through an inline filter for my engine. Also, pulling some clubs do not allow electric add on fuel pumps, add on electric fuel pumps can be viewed as a safety issue because they do not have an automatic fuel shut off and could pump fuel into a fire.

The problem with a block mounted mechanical fuel pump is vapor locking. With a block mounted pump the gas travels in a steel gas line along the right side of the block to the pump and back up the side of the block to the rear of the engine where it is routed behind the block and on to the carb. The fuel lines are bolted solidly to the HOT engine block. Today's fuels contain methanol which is evaporative and are very different then the fuels we used when these tractors were built. They vapor lock easily. An electric fuel pump that bypasses the mechanical pump and all those fuel lines bolted to a hot block is the cure. We have three at the farm that work well. We also found removing the side panels allow more air cool air around the fuel tank. Also don't confuse the air you see in an inline filter as vapor locking. I have never heard off a large inline filter of vapor locking. They do get restricted if not changed once in a while. Another problem often overlooked is dirty fuel tanks. They get refilled by dirty 5 gallon fuel cans. It is a bit of work but removing the tank and getting it cleaned out will help. Take the sediment assembly out and make certain the stand pipe is still in place. The danger of an electric fuel pump causing a fire under ordinary use is very low. This is not a pulling tractor.

I have never had a mechanical fuel pump on an Oliver vapor lock, the inlet is gravity fed from the tank and the line to the carburetor is pressurized by the fuel pump. Vapor lock is caused by having a high spot in a fuel line that is not pressure fed near a heat source. FWIW, I have been using and working on Oliver tractors for 40 years.

I do believe that an electric fuel pump can feed fuel to a fire, that is why all road vehicles have an inertia switch to shut off the fuel pump in the event of an accident. How often it happens on a tractor or other farm equipment can be debated.

I'm sorry if I ruffled anyone's feathers. I only posted what has worked for me. I have been working on Oliver tractors since 1962. It will never happen again. LAST POST.

Don't leave Arnie! Nobody's trying to start anything. It's sure not worth loosing you over an inline filter, that's for sure. If you can mount one back by the tank and make it all down hill from there to the carb, I'm sure they're fine, but most folks just cut the line and put it close to the carb with a big sag in it and after about 20 minutes, they start starving for fuel and don't know why. It's just a problem if it slapped on there by somebody who doesn't know better. Best to use a good new sediment bowl without the filter first is the only point I'm making. Sorry as I can be if anything I said came across wrong.

Arnie, as you said, I only posted what worked for me, I never said you were wrong.

I don't think anyone is ruffled here. Two perspectives, that's all. Don't take your ball and go home over this.

Ford 3cyl gas tractors have a fuel pump when none is needed since the route from tank to carb is almost straight down and short. The block is a diesel block converted to gas operation so you have the pump and 2 tiny filters that plug, right in the front between the engine and the fan. The whole setup is a pain, but it is similar to the oliver situation where there is room for a pump for diesels, but not needed on gas tractors.