Hard Starting SA200

admin

I recently purchased a SA200 green light model. The code on it is 7307, and the SN dates it to 1973. The problem I'm having is that on a cold initial start up, the engine will not start. If I remove the air cleaner assembly, and hold my hand over the carburetor inlet, the engine will fire and eventually start. Once it has been running for 10 minutes or longer, it will start normally within the first 20 minutes of turning it off. So far, I have drained the sediment bowl and replaced the fuel hose and the filter at the carb inlet fitting. I have a good stream of fuel coming from the fuel hose, but it still will not start, acting like it is not getting gas. I then removed the carburetor and completely disassembled it carefully checking the venturi and using compressed air, blew out all the passages and orifices. Reassembled, installed and again the same problem. When I cover the carb inlet with my hand, there is a strong amount of suction. I did notice however that the choke plate has a section at the top that makes for less choking than when placing my hand over the inlet. When the engine does finally start, it runs great with quick governor response and crispness common with SA200s Could the mag timing be off enough to cause this problem or do you guys think it is completely fuel related? Any suggestions would be greatly appreciated.
Reply:Where is your choke? seems to be the missing link.....
Reply:I tend to agree with you about suspecting the timing.  I'd say its slow, but I don't know.The time is easy to set on those machines.  Just remove the air filter and the timing hole is right there.  Use a timing light through the hole and put the "T" on the mark I think I remember all that right.  its been awhile. lolMy dad used to have an old saying:If its hard to start when its cold - then its the plugs.And if its hard to start when its warm - then its the points.Sometimes that proved out right. Good luck
Reply:Originally Posted by bravofabWhere is your choke? seems to be the missing link.....
Reply:The choke plates I have seen on all sorts of engines from chainsaws to SBC were not solid plates.  There is a provision for *some* air to get by.  Have seen a simple small hole or one with a spring-loaded plate over it to act something like a check valve.Gordie -- "I believe you understand what you think I said, but I'm not sure you realize that what you heard is not what I meant."
Reply:The cast carbs were bad to rust if they were unused long enough for the gas to dry. May need to buy a carb kit (probably $20-30) for the brass plugs you will need to replace when you clean the passages out with a tip cleaner. Air doesnt clean them out. You can PM me if you need more detailed info.
Reply:After reading my post I realized I didnt give the reason for my cure. If it takes more vacuum than the choke provides to pull the gas through the passages and orfices, that is an indication that you have restrictions inside the carb and to access those passages you have to remove the plugs on the outside of the carb. Then you can clean them out with a torch tip cleaner. Hope this helps.
Reply:Originally Posted by WCShaleAfter reading my post I realized I didnt give the reason for my cure. If it takes more vacuum than the choke provides to pull the gas through the passages and orfices, that is an indication that you have restrictions inside the carb and to access those passages you have to remove the plugs on the outside of the carb. Then you can clean them out with a torch tip cleaner. Hope this helps.
Reply:Update on my problem. Rebuilt the carb and still had hard starting. So, my next step was to drain the gas and clean the inside of the tank. The last gallon of gas that I drained had  a lot of sediment in it, so I decided to use it to burn a brush pile. When I threw a match at the gas soaked brush it burned very slowly with a great deal of black smoke, almost like igniting kerosene. I then realized that even though the previous owner of this welder claimed he recently filled the tank, the gas was stale. I pumped about 5 gal of fresh gas into the tank and my hard starting problem was cured.