Generac 5000w generator with B&S engine

[bruceb58]

Re: Generac 5000w generator with B&S engine

Have you adjusted the idle mixture so that it runs properly without the choke when it is warmed up?

 

[Scott Danforth]

Re: Generac 5000w generator with B&S engine

unfortunately the Briggs Motors use carbs from china. new they would have metal filings in them causing them to run lean some time, then good the other. it is esepecially bad with their snow engines

I would pull the carb apart and inspect/clean

once the carb is back together run the genny. then addjust the fuel mixture once its warm. they will also hunt a bit without load.

being only a 5k, run it dry when not in use. I never kept fuel in the gennys to make my life easier when I needed them. having a pile of outdoor power equipment, I always have fresh fuel to put in things when needed.

 

[bigdee]

Re: Generac 5000w generator with B&S engine

Have you adjusted the idle mixture so that it runs properly without the choke when it is warmed up?

1^^^ Hunting issues are most often related to the idle mixture. If it won't run with throttle plate in the idle postilion the governor will force the throttle open.

 

[bruceb58]

Re: Generac 5000w generator with B&S engine

I would lock the governor out or temporarily remove it so it just runs at idle and then adjust the idle mixture screw. Do this adjustment when it is fully warm. Basically, turn the mixture screw in/out a little at a time until you get max RPM. Then back out 1/2 turn.

Make sure that the carb mounting gasket is in good shape. Spray some carb cleaner where the carb mounts to the intake. If the engine changes RPM when you do this, you have an intake leak.

 

[dolluper]

Re: Generac 5000w generator with B&S engine

Check your muffler isn't restricted....or bowl nut passage by threads{ very small}l plugged

 

[lakelover]

Re: Generac 5000w generator with B&S engine

Sorry for no action on this, the weather's just been too cold, like 0-10?, to mess with it! I'll update when I can get back at it. Thanks for all the suggestions so far.

 

[lakelover]

Re: Generac 5000w generator with B&S engine

Finally today it was warm enough outside so I could work on it without my fingers freezing to metal right away!

First thing I did was remove the carb bowl. Taking the bottom screw out, the cheap "paper" gasket around it disintegrated right away. Keep in mind this is a brand new carb, "made in Japan". After a little choice language, I made a new one out of rubber gasket material. I just looked things over and didn't really do anything else and put it back together.

This was the first start in 2 weeks. It started right up and ran pretty smooth, absolutely no hunting by the governor. I didn't have to mess with the choke at all, just choke to start it then back it off to "run". Then I got the idle adjusted as good as I could get it.

Here's a new video after a hot restart:

I don't know if I can get it any smoother than that; there is only the one adjusting screw on it.

 

[Tim Frank]

Re: Generac 5000w generator with B&S engine

Number of years doesn't mean he understands and really knows what he is doing. Lots of shade tree mechanics around have been at it since forever but that doesn't make them good mechanics.

I was actually just yanking your chain because it seemed that you had missed the OP's explanation that his mechanic was an "old-charlie"....in the business for 25 years.
It didn't occur to me that you felt competent enough to call the OP's mechanic INcompetent and impugn the OP's judgment, all from 600 miles away.

I apologise for the misunderstanding. :facepalm:

Also:
*****just re-read the OP's OP.
I missed that he needed some choke even AFTER a good warmup. :embarassed:

Maybe Bubba would have been better just to say "I think you still have a carb issue".
I'd have had to agree with that.

I have a genny with a B.S. engine and LOTS of cold weather and never had this issue. (if you have to run it with the choke partly closed the carb. is NOT adjusted properly or needs rebuilt, period, the end. If you have any doubts on that contact B.S. and see what they tell you.)

Oops, almost forgot,,,

I have a number of small 4-stroke gas engines.
With the ever-tightening emission regulations, several of them are designed to run so lean that they are almost "on the edge". *(Some people claim that when Tecumseh went to non-adjustable HS jets, that was their death sentence.)
When they get cold-soaked, it can take a while for them to warm up and smooth out.
My snowblower can take 2-3 minutes to really smooth out when it is south of 25 below. We have had that nearly solidly since early December.

(I think Bigdee had a great post on pretty much that topic.)

That same engine when I'm tuning it and doing pre-winter service in November, can almost start with zero choke....just a touch of the primer bulb.

It seems that with an increase in temps, the OP's gen engine is running well.
That's the best news.