Poulan Pro Riding Mower Over Revving

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I have a Poulan Pro riding mower model PP20VA46 with a Briggs & Stratton Intek 20hp V-Twin engine. A few months ago someone broke into my garden shed and drained the fuel from all my mowers, gas-powered equipment, and my cans. All sat empty with the gas caps open for an unknown period before I discovered the theft after returning from a two-week trip. I refilled the tank of the mower and it ran fine for a while then it began surging. I spent several days learning about this problem and finally managed to fix it. A few days ago it began surging again. Lightly at first, but it rapidly grew worse. I cleaned the carb, replaced the gas (89 type), cleaned the plugs, replaced the filter, etc. Same process as last time. It continued to surge, though not nearly as heavily. Several posts on other forums indicated it might be a governor problem and each suggested adjusting it. I attempted to do just that today and now on startup it revs to the point of redlining. I want to give this my best shot before taking it to a service center. Any suggestions?
 

dfbroxy

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I had the same problem not long ago. I even concluded it was my govenor so I removed the engine and drained the oil only to find it full of gas. The govenor was fine. Check your oil. If it smells of gas then its a carb float and needle problem. AND check your govenor again to be sure you have set it right.
 

bertsmobile1

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I have a Poulan Pro riding mower model PP20VA46 with a Briggs & Stratton Intek 20hp V-Twin engine. A few months ago someone broke into my garden shed and drained the fuel from all my mowers, gas-powered equipment, and my cans. All sat empty with the gas caps open for an unknown period before I discovered the theft after returning from a two-week trip. I refilled the tank of the mower and it ran fine for a while then it began surging. I spent several days learning about this problem and finally managed to fix it. A few days ago it began surging again. Lightly at first, but it rapidly grew worse. I cleaned the carb, replaced the gas (89 type), cleaned the plugs, replaced the filter, etc. Same process as last time. It continued to surge, though not nearly as heavily. Several posts on other forums indicated it might be a governor problem and each suggested adjusting it. I attempted to do just that today and now on startup it revs to the point of redlining. I want to give this my best shot before taking it to a service center. Any suggestions?

Lucky you came here then to get facts rather than face book fantasy.
Surging on a governed engine is ALWAYS due to not enough fuel , END OF STORY .
It can be either from an air leak between the emulsion tube in the carb and the inlet valve,
or
Not enough fuel being delivered to the main jet

The fact that the governor is kicking in then dropping out then kicking in then dropping out proves it is working as intended.

So it is clean everything from the fuel outlet in the fuel tank through to the main jet & emulsion tube.

To check for air leaks rut some WD 40 or similar in a trigger pack, start the engine & soak the area between the engine & the throttle shaft.
You are looking for a change in the engine speed and clouds of white smoke.
It is normal for a SMALL leak around the throttle shaft so expect a small amount of smoke without much change to engine speed when you get to it & start from the engine end.
Do not use a spray can of anything or a highly flameable liquid unless you think singed eyebrows make you look sexy. :ashamed:
 
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Update: Being both stubborn and cheap, I decided to pull the engine (first time doing that by the way) and discovered the governor had, indeed, blew. Not sure why, but all parts show excessive wear. Mower is less than a year old and not overly used. Perhaps they were defective? Anyway, I made a curious discovery: there was no governor washer beneath the gear. The gear was still in place so the washer couldn't have come loose. Only the retaining vanes (terminology?) were blasted. I searched the engine very carefully, even using an endoscope to look in the harder to reach areas. No washer or pieces of a washer. As every video I have watched shows this washer, I ordered a replacement along with the governor assembly. I imagine its possible that the washer was simply not installed when the engine was assembled. Could that have contributed to the destruction of the governor? It ran fine for the past year until the issues I mentioned in my first post. Thank guys!
 

primerbulb120

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Surging on a governed engine is ALWAYS due to not enough fuel , END OF STORY .
It can be either from an air leak between the emulsion tube in the carb and the inlet valve,
or
Not enough fuel being delivered to the main jet

There are three exceptions to this:

1. Some engines will surge if the anti-surge spring is missing or disconnected from the throttle linkage
2. Some engines (Generac 7.8 HP in particular) will surge due to a clogged idle jet, even if the main jet and emulsion tube are spotless. This is still due to lack of fuel though.
3. Most Honda GC160s surge to some extent because the governor linkage is poorly designed.
 
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