Walk behind Gold Series 4.5 Poor running and performance

[Norfolk49]

I have an early 90's Gold Series Self propelled 4.5 HP which I have managed to keep running after replacing the coil. It starts very hard, especially when hot and runs only near the choke position on the throttle. It will not idle at anything close to 1/4 throttle and lacks its usual power. What do I need to look for? Many thanks.

 

[Two-Stroke]

It sounds like it's running too lean (not enough fuel in the fuel/air mixture).

Look for clogging in the fuel system. The first thing I'd do is clean the carb -- I would take it apart and clean all the little passageways with compressed air. Actually, I'd check for a clogged fuel filter before that. :wink:

Let us know how it goes.

 

[Norfolk49]

After all the rain I followed your suggestion and inspected the carb today. Dirty air cleaner and gummy linkage but immaculate carb guts and gas filter. Everything inside spotless. Since I am only owner and it's never been in the shop I re-installed the carb, replaced the plug and cleaned out the exhaust ports (very nice shape) and put in fresh gas. Ran the same but a little better. Then the light bulb went on. The linkage was out of adjustment. To get full power I had to push it to choke and when it was on turtle speed the magneto cutout was engaging. T took some slack out of the linkage at the carb attachment point and turned out idle screw 1/2 turn and it keeps running. Thank you for the suggestions and giving me the motivation and confidence to tackle it myself. A you-tube carb teardown video also helped. What an amazing mower in spite of my neglect! However I do religiously change the air filter and keep the gas fresh with stabil if stored:smile:.