QuestionQUESTION: My pressure washer has a Briggs engine Model Number 150212, Type 0122 E9, Code 070612 with a float bowl carb. It was running along just fine, when suddenly it just quit with kind of a low pop backfire noise. Hoping the problem was simply I was out of gas, I checked the tank and saw it was almost empty, maybe empty enough to cause it to quit. Filled er up with gas and tried starting it and it would run, but only on choke. Move from choke to run and it immediately cuts out. I pulled the bowl off the carb thinking maybe crud in there, did see very slight trace of fleck, emptied it out wiped it out, put it back together and tried starting again. Same thing. Only runs on choke. I took the main jet off and made sure it was clear, I poked a fine tag wire all the way through the holes in it to make sure, then reinstalled and tried again. In fact I did that twice to make sure. Exact same result, no change. So, thinking maybe a failing gasket (air leak), while it was running (with choke closed) I sprayed some carb cleaner behind the carb along the mating surface with the block if the engine to see if the tempo would change, but it didn't change at all. Also I took the fuel line off the tank and examined the entire line from the tank outlet to the line outlet, and all is clear there, no obstruction or restriction. Put things back together and tried again. Same result. Absolutely no change. Runs when carb is choked only. Move to run and it immediately cuts out. Any ideas what could be causing this issue and why what I've tried so far hasn't helped? Must be something I'm missing, it cant be this complex.
ANSWER: The symptom you describe is definitely a fuel starvation problem. The first thing I would check on your unit is the fuel cap vent. To test this loosen the cap and see if this helps.
Clean the tank out to make sure there is no crud inside of it. Put some fuel in it, does the fuel flow freely? Does it flow through the fuel line into the carb.
Make sure you have fresh fuel, If you have water in the fuel this can cause the problems you describe too.
You can even take a remote fuel tank and hook it to the carb to see if perhaps you have tank/line problems.
If all this fails, replace the carb. Even though you cleaned the carb there is still an obstruction somewhere. (I would replace it in the shop too)
Hope this helps...
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QUESTION: I tried it with the fuel cap loosened and that didn't make any difference. I put fuel in it and checked to see that it flows freely; and it does. I've been using fresh fuel, not old. As I mentioned I also took the fuel line off the tank and examined the entire line from the tank outlet to the line outlet, and all is clear there, no obstruction or restriction. I drained the entire tank into a big glass jar and examined for foreign material or water, there was none. I looked carefully inside the tank with a flashlight and saw no crud, and pushed a poker freely from the outside of the tank outlet to the inside, no crud there. Also I took the fuel line off the tank and examined the entire line from the tank outlet to the line outlet, and all is clear there, no obstruction or restriction. I'm certain I don't have tank/line problems. If there's still an obstruction within the carb, it seems like the only place left it would be might be within the passages behind the welch plug, which apparently can be checked/cleaned if that plug is removed according to some rebuild instructions I have for this carb in the Briggs service manual for this engine. Would you suggest I at least try cleaning the passages behind the welsh plug especially since I have the instructions. A new welsh plug would be a lot cheaper than a whole new carb for the thing. Thanks
ANSWER: You could remove the welch plugs and try to clean, but I will tell you from doing this for 30 years it rarely helps. Todays fuel with all the additives are destroying small engine carbs. ITs something our industry (called the OPE industry) has been fighting for several years now.
Some replacement carbs are less then 30 bucks. Our shop charges 80 bucks an hour, so I have to diagnose and repair this problem in less then 15 minutes. If I was faced with this problem I would replace the carb and send it down the road.
Here is how I would troubleshoot this problem:
Step 1: Start engine and confirm that it only will only run on half choke.
Step2 move choke to OPEN position when engine begins to stall spray carb cleaner into carb
(this will reaffirm that engine is indeed starving for fuel and not ignition problem)
Step 3 Set up a remote fuel tank mounted on a stand,
Step 4 Unhook fuel line from carb and hook up line from remote fuel tank
Step 5 Start engine. If same problem, remove carb bowl and clean passages including main nozzle
Step 6 Start again....If cleaning didn't work REPLACE CARB
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QUESTION: Thank you David for your advice and for sharing your expertise. More than likely then I'll be having to buy a replacement carb. nother followup question(s) here for you in regard to the troubleshooting steps you listed in your response.
1. You say start the engine and confirm that it will run only on "half choke". What do you mean by that? As I described, the engine will run only on choke, and by that I meant with the lever in the choke position, full choke I would call that. If I move the lever halfway toward the "run" position (half choke?) it cuts out and dies right away. I've confirmed the engine will run only in the full choke, as opposed to "half choke" position, if that would make any difference in the troubleshooting steps you provided.
2. Why the step of hooking up the fuel line to a remote fuel tank? I checked the tank and fuel line and flow already and, as I mentioned, am certain I don't have tank/line problems.
And, by the way, a new (actually used, apparently) exact replacement carb can be obtained from Briggs and Stratton for $38.30 plus shipping cost to me here in Alaska, I found out. How long, in your experience, does it typically take for all the additives in todays fuel to destroy small engine carbs? thanks again
AnswerSteve:
You did everything right. I was just saying that this is how I would troubleshoot this unit if it came in my shop. I would only be allowed 15 minutes to diagnose and repair based on a shop labor rate of $80.00 without further customer approval. Obtaining further customer approval means making phone calls to reach the customer, thus the clock keeps ticking on the work order...making sense yet..
I misread and thought you said "half choke" weather half choke or full choke, whatever the customer tells me I simply verify the complaint. For example sometimes customers will come in with a complaint of "spark plug miss" on an engine and that could mean the plug is actually bad, or it could indicate a manifold gasket leak, etc... still with me... So step 1 is simply VERIFY CUSTOMER COMPLAINT
STEP 2 is done so i don't need to check the fuel quality, fuel flow, etc...I have a good "KNOWN" fuel supply so if i hook it up to the carb and it works...WALA...its now been narrowed to the fuel supply. In your case the engine would still only run on full choke.
I checked carbs...you need a part number 792970 The BRIGGS AND STRATTON Retail cost for a NEW carb is 37.00 plus shipping. Stay away from a used carb unless you get a warranty with it.
To answer your final question "How long, in your experience, does it typically take for all the additives in todays fuel to destroy small engine carbs?"
It depends where they are manufactured...Chinese manufactured carbs...(YUP they make em for Briggs) i have seen them destroyed in 1 mowing season.... so in just a few short months. Toro had a hellva problem this year with their Chinese engine and carb problems... the carb shafts would seize and not move. TORO did stand behind this for the customer.
I don't recommend any type of fuel stabilizers, additives, nothing...I simply tell customers to rune their engine completely dry. (providing they are not planning on using it in the next 30 days) This seems to work best.
I hope this helps clarify things. I am out of followup questions, but you can contact me at 4cycleengineguy@gmail.com.
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