1450 surging

[rwalker]

Hi All,
Last fall one of my 1450’s began surging when running and was unable to get above mid rpm. I knew the carb had some issues, so I replaced that along with the filter / valve assembly at the base of the fuel tank and hose between last week.

When I started it after parts changes, it still surged for a little and then I was able to get it to run at full throttle with no issues.

It ran great for 10 minutes at full speed and then began to surge again. This time however sometimes when it was trying to recover it would do a loud bang out the exhaust. A couple of times it also spit out the carb.

In the end, it would not get much above idle for speed and was constantly surging, no banging or spitting at this point. It would also die often; restarting was not easy.

I tried playing with the choke when it was surging thinking it might be too lean, that did not help.

Any thoughts?

Thanks, Rich

 

[jkoenig]

How is the fuel tank? Any crud in it? Fuel filler vent ok?

 

[rwalker]

I flushed the tank before installing the new strainer / valve. Good thought on the filler vent.

 

[kmcconaughey]

Sounds like a failing condenser.

 

[kphill]

If it is making a loud backfire out the exaust that means fuel is building up in the cylinder but there is no spark and when it gets spark there is a loud bang from excess fuel.. Sounds like electrical to me..Like Craig says change the condenser and see what happens..

 

[rwalker]

Thank you for the input, I will pick the parts this week.

 

[1811Cub]

Do not forget the spark plug. Autolite or Champion, but a worn or fouled plug will cause all sorts of mayhem. Cheap part to rule out..

 

[Dan Godfrey]

Having the same issue. Curious what the outcome was.

 

[dschwandt]

Start by static timing the engine and go from there.

 

[dschwandt]

Start by static timing the engine and go from there.

http://www.cubfaq.com/questions.htmlFAQ#42