Briggs and Stratton 5 hp (Model 130902) Jet Pulse carburetor problems... Any ideas?

[SmallEngineHead160]

I also should ad that these pulsa-jet carburetors are pretty simple to work on.
The two main bad problems I have found with them are the throttle shaft bushings wearing out and the carb base warping.
A slight warp may or may not be a problem.
Just depends on if it's warped bad enough for the gasket not to seal.

 

[balooba]

Thank you for all the great advices.
mfgsupply.com is a gold mine, thanks!

... two main bad problems I have found with them are the throttle shaft bushings wearing out and the carb base warping...

Okay, I think my carburetor's throttle shaft bushings are more or less loose. Is there anything I can do?

About the ”carb base warping”, I'm not sure where to look.
This carburetor is quite simple...

I tried to inspect the carburetor very closely. Could not really see anything obviously wrong. No lack of fuel. Not especially dirty. Nothing seemed to be broken. I cleaned it (after the photos) but did not open it yet.

Before opening and more cleaning, should I some extra precautions?
For example, how about the adjustement screw, should I remember how much it's screwed?

Here some photos.

 

[Forest#2]

You asked this:
For example, how about the adjustement screw, should I remember how much it's screwed?

Usually around 1 1/2 turns out from a light CW setting. (and this setting is critical on some. (1/8 turn off can result in non-smooth engine performance on some)
It's quite common as the carb diaphragm ages the adjustment screw setting can change and the engine will not run smooth at high rpms and the setting may even change little bit after the engine has run for awhile or as the engine warms up. A new diaphragm will sometimes correct such.
I'm talking about the diaphragm with the flapper valves as it gets old and ages causing the jet adjustment to change. sometimes just 1/8 turn will get it smooth for awhile. I try to keep spare diaphragms in stock and can replace them with the pulsa-jet in place.
Be cautious of all the screws, also the tank screws and do not overtighten and strip the threads.
I've heard of using two carb to tank base gaskets if the top of the tank is warped, but I've never had to do such.


Here is a link that does not exactly match your pulsa-jet but will give you some good ideas about such working on them, just slect Briggs carbs and scroll down to Pulsa jet, tank mounted carbs.

https://outdoorpowerinfo.com/repairs/

 

[SmallEngineHead160]

I think my carburetor's throttle shaft bushings are more or less loose. Is there anything I can do?

About the ”carb base warping”, I'm not sure where to look.

If the throttle shaft is just a little loose it may be fine it just depends on how loose it is.
When they get badly worn the engine will start sucking air through the worn shaft/bushings and start messing up the air fuel mixture going into the engine.
There really is not a practical way to fix it unless you where to ream and install new bushings but I have never really seen anyone do that on these though I'm sure it's possible.
It's something I'm gonna experiment with one day.
But for now I really wouldn't worry about it for the moment until you get that pump diaphragm replaced as more than likely that is your problem.

As for the carb base I will take some pictures and post to show you were to look but judging by your pictures of your carb it seems to look pretty good.

 

[SmallEngineHead160]

Gonna try posting pictures for the second time...
looking at carb base notice left and right corners are warped down slightly from center mainly the left side.
this can cause a uneven sealing surface on the fuel tank.
Again, judging by your pictures of your carburetor I don't think you'll have a problem.

 

[SmallEngineHead160]

I made a quick video overviewing the basics of these carburetors not a very detailed video but hope it may help.

 

[balooba]

I made a quick video overviewing the basics of these carburetors not a very detailed video but hope it may help.

Very good video, thank you very much.

 

[SmallEngineHead160]

Your welcome!

 

[DStahl]

Hello everybody!

I need some help or advice with my Briggs and Stratton 5 hp (Model 130902).
Tje problem seems to be with the Jet Pulse Carburetor.
Very simple, but I'm lost!

View attachment 65692

I can get it run but only without the airfilter – or more specific, without the screw in the middle of the carburetor's air intake (where the choke is).
Any idea what I should do, adjust or check? How should I proceed?

All ideas are welcome.
Thank you in advance!

Whenever I try to clean or rebuild the carb. on any small engine, and it does not run correctly, I jump on ebay and buy a new one for $15. It saves you time and money. Don't throw away your old one though; you can use it for parts one day!

 

[Johner]

Hello everybody!

I need some help or advice with my Briggs and Stratton 5 hp (Model 130902).
Tje problem seems to be with the Jet Pulse Carburetor.
Very simple, but I'm lost!

View attachment 65692

I can get it run but only without the airfilter – or more specific, without the screw in the middle of the carburetor's air intake (where the choke is).
Any idea what I should do, adjust or check? How should I proceed?

All ideas are welcome.
Thank you in advance!

Buy a new filter.