gas double sap guzzler

[Ultimatetreehugger]

Pulling out my hair with my had powered guzzler. I bought it last week, cleaned carb twice, replaced plug. Without pulling vacuum it runs fine, when I hook up to my lines vacuum rises to 18 inches and the engine stutters and shuts off every time no matter if idling or full throttle... Goodriches is stumped as am I. Any ideas appreciated.

[n8hutch]

What kind of engine? Is it A Honda? If so it could be the fuel cap, often they don't vent well and it might run just long enough to build vac and run out of fuel? Try running it with a loose cap.

[MT Pockets Producer]

Does it have a spark arrestor screen over the exhaust outlet and if so is it plugged. Had a similar issue with and engine under load and the screen was plugged. Took it off and it ran fine.

[Jfillion]

Check oil level

[Haynes Forest Products]

Is this a home build unit that could be sized wrong with the pulleys?