Motor dies

[rick_l]

I have a 25 hp motor, the motor needs to be choked each time it is started. Once running it runs fine for about one minute and then speeds up and dies. I assuming the speedy up before it dies is from it running lean at the end. I know its a fuel problem but I have already boiled and rebuilt the carb. If you continue to pump the bulb on the fuel line it will do fine. Any suggestions?

 

[tashasdaddy]

Re: Motor dies

check for air leaks (cracks, loose fittings) in fuel line. if good , change the fuel pump. does you tank have a manual vent, it needs to be open, the new plastic ones usually have a thumb screw on the cap.

 

[JB]

Re: Motor dies

Sounds like fuel delivery to me, Rick. It is using up the fuel in the carb and not getting more.

Common causes are:

* Failing fuel pump.
* Air leak in the fuel delivery system. Most often at a fuel line connection.
* Pinched fuel hose somewhere. The primer can force fuel through but the fuel pump can't.
* Other restriction in the fuel delivery system. . .tank vent, fuel pickup in tank.

Those suggestions apply to engines with fuel pumps and vented tank. If your engine is from the 50s you may have a pressurized tank that isn't holding pressure. Those engines didn't have fuel pumps.

Please check those out and let us know what you find. Also, please tell us exactly which 25hp engine you have.

Good luck.

 

[JB]

Re: Motor dies

AUGH!!

TD outdrew me again!!

 

[rick_l]

Re: Motor dies

thanks, everybody for your response. I will check for leaks, and probably replace the fuel pump.

 

[HighTrim]

Re: Motor dies

Get a vacuum gauge and hook it inline on the fuel hose before the engine, along with a clear section of hose. Take it for a spin, noting the readings and monitor the fuel flow through the clear hose.

Findings:

-Vacuum of less than 2 inches and air bubbles in the clear hose indicates an airleak into the fuel system
-No air bubbles and less than 2 inches indicates a bad fuel pump
-Vacuum over 4 inches indicates a restriction.

Sample gauge

"http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&sspagename=STRK%3AMEBTOX%3AIT&viewitem=&item=4610113711&_trksid=p3984.cTODAY.m238.lVI"