Briggs Engine Will Not Start

mtnlovrs

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At the risk of looking like an ignorant fool ..... by all accounts this engine should be running, I mentioned in another forum or thread ...... one last thing I finally remembered from a Loooong time ago ......... a guy told me he had a similar issue ..... drove him crazy , forget why .... but he removed the muffler and it fired up..... found his muffler was clogged with carbon !! at this stage of the game , MAYBE , it's worth a look-see ?? I really really want to know what the problem is ( I'm sure some others following this thread would also )
I really was thinkin the coil , but ............ Boobala :confused2: :confused2:
Thanks, Boobala. That sounds reasonable. The only thing is... it ran perfect that one time and seemed to run on its own until I killed the engine. Would it have done that with a plugged muffler? Nonetheless, I will definitely try that.:thumbsup:
 

mtnlovrs

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I removed the muffler and tried starting the engine, but it would not fire. I looked the muffler over and did not see any significant carbon build-up. I cleaned it anyway and put it back together. Today, I tried starting it again on the freak chance it would start... it didn't. I removed the armature and cleaned the rust off of it. (I was going to try an armature off a different engine, but the bolt holes were not the same and it would not fit.) So, I figured since I had it off, I might as well clean it before I put it back on. I set the gap at .006" again and put the engine back together. I pressed the primer bulb six times and pulled the cord once, and the engine started! It ran perfect!!! I took it out and mowed the front yard, but before I could finish, the engine began to slow down like it was running out of fuel. I stuck my finger inside the cover and pressed on the throttle to try to keep the engine running, but it died as soon as I pressed on it. I checked the fuel level and it still had half a tank. I pulled the rope again and it started with the first pull. I continued mowing for a while and then it did the same thing again. I lifted up on the handle bar and raised the rear of the mower and the engine immediately sped back up again. I continued mowing and it happened again and again. Each time I was able to keep it running by lifting up on the back of the mower. Finally, I wasn't able to keep it running with the previous method. I rechecked the fuel level and had about a quarter of a tank left. I restarted the engine and it sounded like it was going to stall again. I immediately began pumping the primer bulb and the engine sped up again, but then sounded like it was running out of fuel again. I kept pumping the primer, but couldn't keep it running long enough to finish mowing. It began to rain, so I called it quits, but before I put the mower away, I decided to see if it would start one more time... and it did (one pull starts it every time now), but it would not continue to run.:confused2:
 

Rivets

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Next time it's starts to die quickly remove the gas cap. If it continues to run, the vent in your cap is plugged.
 

mtnlovrs

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Next time it's starts to die quickly remove the gas cap. If it continues to run, the vent in your cap is plugged.

I agree. Every other Briggs engine I have ever seen has a vented gas cap... this one does not. There are no holes in this cap for venting. I tried removing the cap to see if it would help, but all it did was slosh fuel.
 

mtnlovrs

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While mowing yesterday, the height adjustment handle fell off and the mower dropped to its lowest adjustment. This was the "final straw", as they say... it was raining, the engine kept stalling, and now this. I quit mowing at that time and I didn't mention it before because I thought it was no big deal. I went out today to put the handle back on and discovered that the right hand drive axle had been cut in two by the handle. The hardened spring steel of the handle acted just like a blade and cut all the way through it. My wife found the drive axle on the Internet for $35 bucks, so I guess that's the next hurdle. I called my mom and let her know the good news and she said she wants to go get a new mower, but she still wants me to fix this one so that she has a back-up mower.:ashamed:
 

bubbatime

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I work on a ton of these Briggs flat heads and love fixing them up. So easy to get them going (usually). Couple of things for future reference.

1) Never rebuild these carbs. Rebuild kit is like $12, while a new carb is barely over $20. My time is worth more than $8, and a rebuilt carb doesn't work right 50% of the time. Just replace them for a much smaller headache. I've used a bunch of OEM carbs as well as the Chinese Oregon ones and they all run the same.

2) I personally only use Champion RJ19LM in these. Made in USA and good quality. Have had bad luck with other brands for some reason.

3) Gap at 0.020 if you think your coil is getting weak or if unsure you have spark. Run the gap at 0.030 for a good running engine, but knock it down to .020 for coil diagnostic or to limp along a dying coil.

4) I'm almost positive that your problem is a clogged up carburetor. It is really hard to clean behind the welch plugs. I'd put a new carb on it and chock it up as a lesson learned. Should start right up and run perfect with a new carb.

5) Replace the fuel line at the same time. I've seen them get spongy inside and slow fuel down.
 

motoman

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Two bits...Don't put gasket seal on a head gasket which does not call for it. My old song on spark...The modules contain transistors or other electronic devices that fail at hot, but will spark at cold. A spark guru recently posted that some excellent sparks are invisible. "Thin" and "thick" descriptions of spark, as well as color are not useful. Try a white paper as a background for the spark at hot. The intek factory manual published 60-65 psi as compression spec. This is for the V engines. Does not state take hot or cold. I once used an automotive inductive timing light on my Intek. The spark is so weak it barely strobes weak orange, but was at least a way to determine a rough measure of timing. You can set in a TDC ref prick punch mark on your engine to help you if you try the light. Shroud removed,
 

mtnlovrs

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I work on a ton of these Briggs flat heads and love fixing them up. So easy to get them going (usually). Couple of things for future reference.

1) Never rebuild these carbs. Rebuild kit is like $12, while a new carb is barely over $20. My time is worth more than $8, and a rebuilt carb doesn't work right 50% of the time. Just replace them for a much smaller headache. I've used a bunch of OEM carbs as well as the Chinese Oregon ones and they all run the same.

2) I personally only use Champion RJ19LM in these. Made in USA and good quality. Have had bad luck with other brands for some reason.

3) Gap at 0.020 if you think your coil is getting weak or if unsure you have spark. Run the gap at 0.030 for a good running engine, but knock it down to .020 for coil diagnostic or to limp along a dying coil.

4) I'm almost positive that your problem is a clogged up carburetor. It is really hard to clean behind the welch plugs. I'd put a new carb on it and chock it up as a lesson learned. Should start right up and run perfect with a new carb.

5) Replace the fuel line at the same time. I've seen them get spongy inside and slow fuel down.

1. Easy to work on... yes, that was my experience also, until I met this one!
2. Where do you get your parts? The Carb overhaul kit cost me $16 and the best price I saw on the Internet for a new carb was $35. We have only one store in town that sell these parts and they have bankers hours. I have never heard of Chinese Oregon. Where do you buy these?
3. I started with a brand new Champion RJ19LM spark plug. I tried three different brand new plugs, (2 Champion, 1 Briggs), and a used "known good" Briggs plug. I finally got it running with a new Briggs plug gapped at .030". I will try your idea of the .020" gap in the future.
4. I know I don't have any clogged ports. I was able to blow compressed air through every port after cleaning the carb - confirming the ports are clear. The carb has only one welch plug, which I removed and was able to clean the port (or orifice) with a drill bit matching the diameter of the port, and then I blew compressed air through the port and had a strong blast of air coming out the other end. This was the primer bulb port that sucks fuel from the float bowl. Then I applied a new welch plug from the overhaul kit. I may still end up buying a new carb before this is all over, but this carb is such a simple design, I really don't understand why it is not performing as new.
5. Lastly, I replaced the fuel hose before I ever attempted to start the engine the first time.
Thank you for your ideas, keep them coming!
 

mtnlovrs

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Two bits...Don't put gasket seal on a head gasket which does not call for it. My old song on spark...The modules contain transistors or other electronic devices that fail at hot, but will spark at cold. A spark guru recently posted that some excellent sparks are invisible. "Thin" and "thick" descriptions of spark, as well as color are not useful. Try a white paper as a background for the spark at hot. The intek factory manual published 60-65 psi as compression spec. This is for the V engines. Does not state take hot or cold. I once used an automotive inductive timing light on my Intek. The spark is so weak it barely strobes weak orange, but was at least a way to determine a rough measure of timing. You can set in a TDC ref prick punch mark on your engine to help you if you try the light. Shroud removed,

Yes, I know you aren't supposed to use gasket sealer on the head gasket, but I had no choice. The parts store was closed for the weekend and the gasket was damaged. I have used the Permatex copper spray-on gasket sealer in the past with great success. You use a cardboard box or box lid. Place the cleaned gasket into the box and paint a thin coat on both sides of the gasket. Wait for it to get tacky before applying the gasket and reassembling. Of coarse, make sure all the mating surfaces are clean before hand.
I have seen plenty of old warn-out Briggs engines run well with low compression, burning lots of oil and smoking like crazy! If it were a diesel, I would agree. Maybe it's the weak spark these newer engines produce with the solid-state ignition. Cleaning the rust off the armature definitely seemed to help.
 
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