Engine Z445/w 27HP Briggs engine surge

[Glyn Robinson]

:thumbsup:

 

[PJ]

I've had this since new. Like the title says 27 horsepower Briggs. About 275 hours. Bought it 5 years ago. Has new spark plugs, fuel filter, oil and filter, air filter also. You can't do any adjusting to the carburetor. When it gets to operating temperature it begins to surge up and down in RPM. As soon as you engage the PTO for the blade it smooths out and runs fine. Anybody else have this problem? Solution? Ed Dowdy Fithian IL

Engine serge could be caused by a sticky or a defective needle and seed please check your carburetor
Regards
PJ

 

[eldowdy]

Thanks PJ,

I should have the repair kit for the carb in the morning!

Ed

 

[eldowdy]

Well the carb wasn't the culprit. I suspect the governor. When I am mowing this thing runs fine. It's when the blade PTO is disengaged at high engine RPM that it becomes a problem. I don't know anything about the governor. Only thing I can find in the available download it the parts description and diagram of the engine. Only thing I could see there was a reference number 227 for the governor lever. I couldn't find it on the schematic. Is there an adjustment to the governor I didn't see? It's a briggs 44Q900. Specific version is 0110. The plate where all the linkages attach is 222B. I'm a scratching my head.

Ed Dowdy

 

[BlazNT]

Cleaning a carburetor is not easy and most people miss steps. You can view 2 videos that cover cleaning a carb. See if you missed something.

Down and dirty: https://www.youtube.com/watch?v=VBL-BUj0c6E
More technical: https://www.youtube.com/watch?v=nAk_WDt3AD8

 

[eldowdy]

Cleaning a carburetor is not easy and most people miss steps. You can view 2 videos that cover cleaning a carb. See if you missed something.

Down and dirty: https://www.youtube.com/watch?v=VBL-BUj0c6E
More technical: https://www.youtube.com/watch?v=nAk_WDt3AD8

I didn't miss anything. Good videos. Especially the Tecumseh engine on the snow blower. I think my snow blower needs some attention! Once I disengage the blade PTO at mowing engine speed it surges. If I throttle it back a tiny bit it runs OK. If I throttle it clear back to idle it runs OK. The only thing adjustable on this carb is the stop for the choke All it does is keep the choke from closing completely. Engine was manufactured in May of 2011.

Ed

 

[BlazNT]

I am wondering if the main jet is a tiny bit too small. Mostly because you said it has been going on since new. I know we don't really condone drilling the jets larger but it might just work in this case. Only other thing to would be adjust the goviner. Lots of videos on how to do it on YouTube.

 

[eldowdy]

I am wondering if the main jet is a tiny bit too small. Mostly because you said it has been going on since new. I know we don't really condone drilling the jets larger but it might just work in this case. Only other thing to would be adjust the goviner. Lots of videos on how to do it on YouTube.

I did not say it has been going on since new. It started at the last year. It has a fuel servo at the bottom of the bowl. I just wonder if that is the problem. The carb was squeaky clean when I installed the repair kit.

Ed

 

[eldowdy]

I am wondering if the main jet is a tiny bit too small. Mostly because you said it has been going on since new. I know we don't really condone drilling the jets larger but it might just work in this case. Only other thing to would be adjust the goviner. Lots of videos on how to do it on YouTube.

I see why you thought it was happening since new. I just meant I had purchased it new.

Ed

 

[JD318420]

Try running some seafoam in the tank first, It should clean out any buildup. It will take a couple of tanks. Cheap easy 1st try solution, All gas is crap these days.