18Mar2009
Mower: Craftsman 18.5 HP OHV, 46”, electric start, automatic transmission
Engine: Briggs and Stratton, twin cylinder, OHV, Model number 407777, Type 0121 E1, 1/C Platinum, InTek, purchased Nov, 1999.
What I did:
Checked that both spark plugs are firing; the fuel pump is working (pressure in the output line to the carburetor); solenoid was checked, it works; 12v is present to solenoid when ignition turned on; installed overhaul kit in carburetor (gas poured out of carburetor when detached); blew out all ports and recesses with carburetor cleaner; did not detach solenoid at base of bowl. (Have no idea what the function of the solenoid does.)
There were some O-rings and small sponge rings left over that I could not determine where they went and/or were parts I assume for other carburetor designs that had no counterparts in mine.
After turning the engine over for quite a while, pulling the plugs shows that the electrodes are dry, no gas getting to them!
Last used and ran fine fall, 2008.
Any idea what might be wrong?
Spray carb cleaner does not qwork well to clean the interior of the carb. It has to be soak in a soaking carb cleaning solution for about 1/2 an hour or so. Also need to soak and blow out the main jet.
How did you verify that the fuel shutoff solenoid is working?
The technician at the repair shop checked the selonoid where I ordered the overhaul kit.
I was guessing the problem may still be with the carburetor and will do a more thorough cleaning job. Thanks.
Also, now that I think of it, how do I identify the main jet?
Try putting about a teaspoon of fuel in each cylinder, then try to start it before you dismantle it again. A spark plug doesn't always show the fuel on the tip if the there is fuel in the cylinder.
If you have it put together correctly it may start and clean itself up a little. Sea Foam is a good first try on a varnished carb for an on engine cleaning.
Thanks for the idea. Will try it next.
Hi to all, I think that I have the same engine on my Craftman mower and I had the same problem twice in the last 3 years.
I did take off the four philips screws on the bowl and replaced them allen head screws, I did clean and blew out every thing inside the bowl includding the main jet just be careful not to move the float level, I used a welding torch tip cleaner for the really small passages in the carb body, I could tell there were some plugged by the resistance when I pushed the tip cleaner in and out, also the left over parts you have I belive go inside the bowl and /or the main jet.
I am confident that you will find the problem after removing the bowl and cleaning the passages
the first time It took me a while to figure it out, the second time I knew exactly where to go, let us know how it went
Reply to marbobj…
23Mar09:
After putting a teaspoon of gas into each cylinder, the engine ran for several seconds, then died. Proves it’s a gas supply problem.
23Mar2009
Reply to Indypower and Happy Rat:
I’ve cleaned this carburetor like I’ve never cleaned a carburetor before. I’ve blown out all the ports with compressed air, soaked the thing in Chem Dip, Carburetor Parts Cleaner, for a half hour, rinsed it in distilled water twice, and again blown out and dried all ports, holes, cavities, and passageways with compressed air. I’ve held up the carburetor so that all the ports were back lighted with either sun or skylight so I could see reflected light glints inside the passage ways indicating they are open and clear. I found only one port that had an obstruction inside it that the soak did not remove, so with probes and the thinnest of needles, I prodded around and finally broke loose and blew out the blockage with compressed air. And the engine still does not run after installation!
I’m wondering if the problem is in the solenoid assembly at the base of the bowl, since I did not do much other than spray it with carburetor cleaner. I had it tested and tested it myself; I can hear it click when the ignition key is turned to the first position, and measured 12 volts on the connection contacts, but maybe it is not functioning right.
What else can there be?
If you hear the fuel solenoid click, then it's working. The click is the sound of the plunger moving...and if the plunger moves down, it is working. Is the seal between the intake and heads good?
24Mar09
reply to cheese:
Yes, all gaskets good and tight.
Is there fuel in the bowl of the carb?
25Mar09
reply to BFHFixti:
Yes. I have check several times, there always is fuel in the bowl.
Just tested the solenoid again, two different ways, with the connector from the ignition switch and with a jumper wires directly from the battery. Doesn't seem to be working. May be intermittent or “sticky.” Plan to get another. Will let you know.
27Mar09
Got the engine running! I removed the solenoid and put a “plug” (a bolt and nut using the solenoid washer gasket) in as a temp replacement. When I had the solenoid out I depressed the plunger several times. It always snapped open when applying some force; it was sticking closed; it was the problem. Can it be cleaned?
I have not had much luck trying to salvage them. I have replaced them with a like bolt ( same thread length and size). As far as I have been able to find out, this solenoid is for anti backfire purposes when shutting off the engine so if you use a bolt then start having backfire symptoms, you may want to re install a solenoid.
Some of these are an uncommon thread and the part is not that expensive. In some cases it may be easier to replace the solenoid rather than finding a correct bolt or if you want to keep the original configuration.
I bought a 7/16 nut and bolt, cut down the bolt to about 1/4”, slipped on the solenoid washer gasket, and it works fine. Dealers want between $50 – $67 for a new one. Will try living with the bolt.
And thanks everyone for all you advice and help to me in getting this mower engine running,
But now there’s a new problem. Maybe I should post a new thread: after running the mower around the yard a short while, I engaged the blades. That abruptly sent the engine into labored stress, almost killing the engine, spitting out gray smoke, and running rough. Immediately I disengaged the blades, but the engine now continues to run rough, hardly above an idle. Throttling up stalls the engine. Now what might be wrong? It has an electric clutch, so is there any connection with the engine function? I tried disconnecting the clutch wires, but that was of no avail.
Is the oil level overfull? Does the oil smell like gas?
I am starting a new thread; please go to: Briggs Stratton 18.5HP runs rough, dark exhaust. Your question will be answered there. Thank you.
Tags: briggs, stratton, start, Briggs Stratton, with carburetor, with compressed, base bowl, carburetor cleaner, cleaning Thanks, each cylinder, engine running
