B&S 4.5 HP sudden problems.

[Whimsey]

I have a 2005ish Troy-Bilt pressure washer I bought new. It has a 4.5HP L head B&S engine. I replaced the original carb last Fall with a new B&S carb as it would not start any more. It also has a new AR water pump I installed last year. It worked great for 3 hours this past weekend then all of a sudden it would hunt severely at idle. It worked better but not good under load. Now it works bad under load as well as at idle. All the gas was from the same 2 gallon plastic container, less than 6 months old. Today it sounded like a metallic noise when starting but not when running. It still idled and worked poorly under load. The oil has been changed faithfully and is new from last Fall and is still full after the 3 hours of use. Also when I changed the carb last Fall I rinsed the fuel tank out. I'm stumped

, any ideas would be helpful. The engine is a B&S # 10H902-0113-E1. Also there is not a lot of hours on this engine, maybe 25. Thanks

Whimsey

 

[old1]

As always, could be several things. Sounds like it is running lean, as in something plugging some circuit in the carb. Also, the metallic sound when starting sounds like maybe the pump mounting is loose. Sometimes a loose driven part will cause a flywheel key to partially shear. I think I would check that before tearing down the carb. Of course I would probably change the gas out with FRESH gas before doing anything else.

 

[bubbatime]

Carb is plugged up. Since it is so new, take it apart and spray every orifice with carb cleaner. Then you need to add a Briggs fuel filter so it doesn't happen again.

Or

6 month old gas CAN be really old and stale, depending on the gas station, storage conditions, gas can type, and if fuel stabilizer was used. If your gas can is an older style with a vent, the ethanol in the gas is hydroscopic. It absorbs water from the air, as much as 5-10% of the gasoline over a 6 month storage, which makes for a poor running engine.

Replace the gas, flush the tank.

Honestly, if it was mine, this is what I would do:

New aftermarket carburetor (Oregon brand or similiar). They are made in China, but are cheaper and I have never had a problem with them. Flush out tank again. Install Briggs style fuel filter and replace the fuel line if it is over 10 years old. Fuel up with fresh gas from the station. Done.

Dont forget to check the air filter and plug for condition while you are at it.

 

[Merkava_4]

Originally Posted By: Whimsey
The engine is a B&S # 10H902-0113-E1.


You'll be fine; I happen to be an expert on that engine.

Go to ebay and enter "briggs stratton 795475" into the search box. Buy that carburetor
along with replacement diaphragm /tank gasket kit 495770. Some sellers will include
the diaphragm kit in with the carburetor. Don't buy the black knock off carburetor from
Hong Kong.

I have done extensive research on that engine because I have one on my Craftsman mower.
After all the research, I have found out that carburetor 795475 is the one carburetor that's not jetted
too lean. As soon as you pop it on your engine, all the surging disappears and you have a
smooth running engine again.

Don't forget to install the spring #390 or the engine will be hard to start.

http://outdoorpowerinfo.com/repairs/briggs_pulsa-prime_carb.asp

http://outdoorpowerinfo.com/repairs/briggs_10l900_carb.asp

That is a tank mounted carburetor with two fuel inlet screens. The screens clog up with debris real easy
if your don't keep the fuel clean. A Mr. Funnel will prevent that.

And if you would like a free service manual, send me a PM with your Gmail address.

 

[Merkava_4]

http://www.mrfunnel.com/Mr._Funnel/Models.html

The Model F3 is just right for small engines.

 

[pdxglocker9mm]

That is my least favorite b&s carb. Though as long as the gaskets are not too old they are pretty easy to clean.
I like the b&s carb with the float bowl best.

 

[Merkava_4]

Originally Posted By: pdxglocker9mm
That is my least favorite b&s carb.


Why ? I works good and is inexpensive to replace. You just gotta stay away from the CA models.

 

[bubbatime]

Good post by Merkava. I thought for sure we were talking about a Briggs quantum engine. Should have looked at the numbers.

 

[Ifixyawata]

I was going to start a new thread but I'm running into similar issues with a similar engine, albeit on a mower belonging to my neighbor.

He brought me is old push mower over last week stating that he could only get it to run by priming and/or using starting fluid, then it would die. The fuel tank looked rather dirty, so I pulled the tank/carb off and when I separated the two I found the diaphragm to be very stiff and worn-out looking. I found the replacement for $6 on Amazon and thought it would likely cure the issue.

After cleaning out the carb and the tank, replacing the gasket, diaphragm, spring and filter screen, the problem is not much better. It will start and run, wander up and down for a bit and then settle in to a somewhat smooth idle with an occasional backfire. However, if you introduce any sort of load or jostle the unit around at all it will sputter and die.

It seems to me that it's still not getting enough fuel, though I can't be sure. I want to say that the best and easiest solution would be to buy THIS carb and replace it entirely and it should be good to go, but I still feel like i'm throwing parts.

Anyone have a more expert opinion or anything else I can check to nail it down as the carburetor at fault?

It's Model 10A902 Type 2189 B1 Code 00030854 4hp Quattro

 

[Merkava_4]

Originally Posted By: Ifixyawata
Anyone have a more expert opinion or anything else I can check to nail it down as the carburetor at fault?

It's Model 10A902 Type 2189 B1 Code 00030854 4hp Quattro


Yours is pretty much the same engine as mine. 10M902 0489 E2 05101754

I looked yours up, it has the same lean running carb that mine came with. I did extensive research on that engine because I wanted to find the carb part number that was the most widely used in states that are not CARB regulated. The internet can be your friend sometimes. I'd suggest you switch over to the 795475. That carb is not legal in California which means it'll allow the engine to run good.

One other note: There's also a plastic emulsion tube in that carb. The way you remove it is insert a large flat blade screwdriver into the venturi and press down on the tip of the emulsion tube. What you'll feel is the resistance that the O-rings are giving you. Once you overcome the O-ring retention force, the emulsion tube will pop out. There's holes in the emulsion tube that could potentially become blocked by debris. Visit those links I posted above to see the picture of the emulsion tube. Make sure you place the diaphragm against the tank and then the gasket on top of the diaphragm. Torque the screws in a clockwise pattern.

 

[Whimsey]

Thanks everybody. I found out the metallic clanking was the pump loosening up. I tightened the 3 bolts and no more metallic clanking. As I said the carb was purchased last year and only run for maybe a total of 3 1/2 hours. I removed the carb and the tank, both were clean. I removed the emulsion tube and the holes were clean. The screens on the pick up tube and the emulsion tube were clean also. As I said it ran great for 3 hours and then all of a sudden it began to hunt severely using the same fuel. I ordered another B&S carb and will see what happens. I'll have plenty of spare carb parts now

.

Whimsey