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What's left to check?


GWGAllisfan

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After working on my B-10 several times and never being able to make it run I bought a new carb for my B-10, and installed it today. After getting fuel to the carb, I was able to start the engine and run it for several minutes, long enough to adjust the carb and re-install the air filter, etc. (At least 30-40 minutes) I then took it on a ride around the yard, where it seemed, for lack of a better word, to "surge" I would stop and for some reason there was an occasional puff of smoke (Black) almost like it was too rich, but not continously. All this time I was able to shut it off and it restart. But then, just As I thought I had it, it stopped and would not re-start. It seems to be flooded, but I can't get it to clear and start. A new carb shouldn't do this. The only other thing I noticed, is when I tried to start it and closed the throttle while cranking, there was a whistle like the intake and carb weren't sealing to each other. There seems to be some fuel leakage out of that connection. Has anyone ever had a warped intake manifold? Maybe I should take the manifold to a machine shop and have it milled flat? I was reasoning that the engine could get enough vaccum to pull the fuel to the cylinder. I have tried everything I know and still this Allis defies me, so yet again I call on wiser persons for advice.
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You can leak test by useing a fuel source to spray around the gaskets at the intake. Most of the time I use acyteline or smpler some spray carb cleaner. The idea is to put some extra fuel into the leak where its sucking air to even out the mixture. This will raise the rpm's a little so it will be very noticable. If you do have a small leak, your options are replaceing/repairing the manifold or if the leak is small enough you may double gasket the connection and get it to seal. Checking it over is fine, but if you don't have any leaks and after several attempts to adjust the carb have failed, don't forget you could have points, condenser, or plug problems.
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If I can ever get it to start I'll try that. I suspect the excess air is making the fuel droplets fall out before they can get up the manifold.
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The fuel isn't in dropplets. When the fuel passes through the center of the carb it speeds up in whats called the ventury. This accelarates the air flow causeing a drop in air presure allowing the ambiant outside air pressuere to force liqiud gas out of the carb. bowl into the airstream. This turns the liquid gas to a vapor mixture of air and fuel. This is what burns. Liquid gas does not burn, only the vapor off the fuel burns. Now what a leak does is induce air into the mixture and leans the mixture aof air and fuel vapor towards the lean side. Just like you turned the needle on the carb. in. Now besides not running well, this is highlt detraminal to the engine as a lean mixture burns much hotter. I've seen it melt pistons under prolonged loads with leaking intake gaskets or just lean mixtures. Also the speeding up of the airflow and drop in air pressure lowers the intake air temp some and cools the intake manifold. This is where the effects of frosting comes from on the outside of some intake manifolds if conditions are right and it'll also make the moister in the air condensate and turn from a gas to a liqiud inside the manifold such as winter iceing up and chokeing the engine out when snowblowing. This is a result of water and gas haveing diff. vaporazation temps. Now my fingers are tired, and we've had our science lesson for tonight.lol I hope this made sence.
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Maybe i can get it started tomorrow...If I can get it started then i can adjust the carb so maybe it will stop flooding...If I can get it to run at least fair, then I may look at ignition for further tuning. It has been converted to an electronic so point adjustment isn't available... will keep all of you posted on progress. thanks for the help If I can get the allis to run then I can start on the landlord....
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If the Briggs engine on the B10 is similar to the one on my 2110,there are 2 gaskets used,where the intake bolts to the engine.One between the intake,and shroud,and one between the shroud,and block.I ended up removing the bolts that held the intake to the engine,and replacing them with small studs,so everything was easier to keep in place.
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I got it to start this morning. after setting all night the flooding seemsd to clear. It was running ragged and rough, but running. I didn't run it for too long as a it is a bit too loud for early morning on a 1/2 acre lot. The way I can't get it to settle down is aggravating, but at least it starts now. At least now I have hope.
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