Starting 717 after rebuild

[RobertWrath]

I have a '98 GTi that would do 50mph and ran great before a poorly repaired welch plug gave out. That tried to sink it and it got towed too fast. I had the engine rebuilt, didn't touch the carb, and have it back in the hull with full carb setup and only exhaust manifold.
Is it ok to test fire it without the exhaust attached? I'd prefer to not fully install for testing in case it has to come out again.
I plan on putting a little oil on the heads and running first tank pre-mix.
Do I still need to try priming the fuel and oil lines or let the pumps sort it out when trying to start it?
What is best practice for firing up a rebuild?
Thanks!!

 

[lagojaguarasp]

Good question! I have my cone and muffler out for repairs ('01 GS) and i also wonder if i can start it up like that. Regarding fuel line priming, i made a shunt between the carb fuel and return lines with a outboard primming bulb and a fuel petcock: The bulb sucks fuel from the carb line and pushes it through the return line. When its all primed, i close this petcock so this "priming circuit"with the outboard bulb is totally isolated. Nice to save some battery and starter wear!

 

[burtshaver2021]

I’ve never primed the fuel system after rebuilding, just pull the choke and after cranking for 2 or 3 seconds it fires up. Good idea to premix the first tank of fuel 40:1 besides the injection oil after a rebuild as long as it’s carbureted and not injected. You will need to get the air bubbles out of the oil line and filter from the tank to the oil pump, start by taking the line off after the filter, turn it vertically While keeping it below the oil tank, after a second or two the air will be all out of the line and filter, push it back onto the hose to the pump, then bleed the oil pump. When you first start the machine, reach down and hold the oil lever to full open and you can watch the new small oil lines fill up with oil in about 3 seconds or so. Usually some assembly lube is used while rebuilding to avoid dry starts, or 2t oil used as assembly lube, but if not, I guess some 2T oil in the plug holes and in the intake if the carb is still off would be good. I wouldn’t fire it up without the exhaust and air box on, if it’s rebuilt properly, ring end gap is correct, piston to cylinder wall clearance correct etc. Set the carb to factory settings, there’s no reason to have to pull it again.

 

[SIMPLEARKANSAN]

Easiest way that I have found to prime the fuel system is to remove the return gas line and blow into the line until gas exits the carb at the return line nipple.

 

[lagojaguarasp]

I’ve never primed the fuel system after rebuilding, just pull the choke and after cranking for 2 or 3 seconds it fires up. Good idea to premix the first tank of fuel 40:1 besides the injection oil after a rebuild as long as it’s carbureted and not injected. You will need to get the air bubbles out of the oil line and filter from the tank to the oil pump, start by taking the line off after the filter, turn it vertically While keeping it below the oil tank, after a second or two the air will be all out of the line and filter, push it back onto the hose to the pump, then bleed the oil pump. When you first start the machine, reach down and hold the oil lever to full open and you can watch the new small oil lines fill up with oil in about 3 seconds or so. Usually some assembly lube is used while rebuilding to avoid dry starts, or 2t oil used as assembly lube, but if not, I guess some 2T oil in the plug holes and in the intake if the carb is still off would be good. I wouldn’t fire it up without the exhaust and air box on, if it’s rebuilt properly, ring end gap is correct, piston to cylinder wall clearance correct etc. Set the carb to factory settings, there’s no reason to have to pull it again.

Maybe I have a bad fuel petcock

Easiest way that I have found to prime the fuel system is to remove the return gas line and blow into the line until gas exits the carb at the return line nipple.

THAT is a neat trick!

 

[burtshaver2021]

That’s a possibility

 

[mikidymac]

Easiest way that I have found to prime the fuel system is to remove the return gas line and blow into the line until gas exits the carb at the return line nipple.

Much safer to hold your thumb over the return and blow into the one-way check-valve on the tank vent. I have gotten a face of fuel by blowing into the return line. Only took once to learn my lesson.