fuel loosing Prime?

[JDCam]

Hello All,
I picked up a 96 GTi a couple weeks ago. Its a bit difficult to start, but once its running and warmed up it runs real nice.
If it has sat for a day or two, I need to run the starter for up to two minutes before it fires up. Once it does fire, I get clouds of smoke for another minute until it burns off the excess. oil. It feels like there is no fuel at the carb. If this was an outboard, I would want to squeeze the bulb go get some fuel pressure.

Can anyone point me in the right direction, I don't want to start messing with the engine without a better idea of whats wrong.

Cam

 

[JDCam]

Maybe the diaphragm in the fuel pump?

 

[JeremyD615]

Start with the simple things first. Have the plugs been replaced and the plug wires trimmed back? Have you checked the o ring on the water separator and made sure it’s snug?

 

[Sportster-2001-951C-Stock]

Is this smoke from oil? If your inner crank seals are leaking some, this allows oil to seep into the crankcase and will make starting more difficult due to the oil. Primarily cold starting though, and the smoke will be from excess oil burning.

There are several things necessary to run; ignition, fuel, air and compression all must be within reasonable parameters Your ignition sounds fine, that leaves three unknowns.

1st place to begin always, is by confirming cylinder compression. If too low, this must be addressed before proceeding.

For hard starting, need to diagnose if there's too much fuel or too little. Too much fuel can also result in some smoke at startup and hard starting but also lack of fuel can cause hard starting as well. The ratio of air/fuel must be in the flammable range, not too rich or too lean.

In the case your carburetors are fuel-flooding,, if opening the throttle a fair bit while cranking will help, this indicates too much fuel. The spark plugs might be wet with fuel in the case of gross fuel flooding.

In the case there's a lack of fuel, if applying choke helps the re-start process, this indicates there might not be enough fuel.

 

[JDCam]

Thank you.. some great suggestions to help me narrow down the issue a little further.

I should add... as long as it has run in the last couple hours, it starts again instantly with no issues. Problems only begin when it sits for a day or more.

 

[Sportster-2001-951C-Stock]

Thank you.. some great suggestions to help me narrow down the issue a little further.

I should add... as long as it has run in the last couple hours, it starts again instantly with no issues. Problems only begin when it sits for a day or more.

Assuming it's an oil control issue;

There's an oil supply for the rotary valve gear bath, this is the cavity that can leak oil into the crankcase while sitting static for days or hours even, the oil slowly moves through one or both of the crankshaft seals and into the crankcase. To isolate this from occurring, it's possible to disrupt that oil supply. If you determine this might be a solution for your purposes, remember the oil bath has to be turned back on while running the engine else the gears will be damaged from lack of lubrication.

Some have installed a small ball valve for the purpose of shutting off the oil supply, and tie a string onto the valve leading out of the compartment or hang their DESS key on the valve handle as a reminder.

If these seals are leaking, the final solution is to replace the crankshaft.

 

[JDCam]

I notice that ball valves had been added to both Oil and fuel lines by someone in the past... I would assume this is why. I will start by turning these off when not in use and see if things improve.
Much appreciated.