Scotmo Posted August 7, 2003 Posted August 7, 2003 The wife complained our 6216 would not start. Sure enough it would not. I checked the oil only to find out my crankcase was FULL of gas. Naturally I freaked. The starter will engage but will not turn the engine over. I pulled the plugs and both looked good and were dry as a bone.The engine turns easily by hand with the plugs out. I changed the oil in June and had no problem until today. Any thoughts on where to begin to remedy this........Thanks Scot
Dutch Posted August 7, 2003 Posted August 7, 2003 If it were me, I'd drain the crankcase, put in fresh oil and try to start the engine. If it runs okay, I'd then find the reason gas is getting into the crankcase and correct that.
pofarm Posted August 7, 2003 Posted August 7, 2003 Without knowing what brand motor you have I'll just have to guess what the problem may be. I gather from your post that it is a two cylinder? Does it have a mechanical fuel pump? If so the diaphragm may be bad and leaking gas into the crankcase, requiring a new pump to fix it. Depending on the design of the carb, if the float valve isn't closing completely, it may be running gas by the intake valve stem into the crankcase while the tractor isn't running. I can't think of anything else, right now, that could cause it. Maybe someone else has ideas??? DON'T start the engine without first draining the crankcase and refilling with fresh oil. At best, you may score a cylinder and at worst, you can blow the motor up.
Stoneheartfarm Posted August 7, 2003 Posted August 7, 2003 I'd agree that you should change the oil before doing anything else. I think I might also put a little oil down each cylinder and spin the engine over by hand a few times, just to make sure the cylinders are lubed. Don't know if the engine ran with gas in the oil or if it just got there when you tried to start it? Steve
MPH Posted August 7, 2003 Posted August 7, 2003 My guess would be the fuel pump diaphragm if the engine has is so equipped. My Onan was doing that when I found it, put an electric pump on it and its still running. Most deffenntly change the oil before you start it, think I changed mine 3 or 4 times before I found the cause, every time I went out to work on it it would have an extra qt of oil in it. The crankcase being full of gas may be the cause of too much compression to turn over...MPH
Scotmo Posted August 7, 2003 Author Posted August 7, 2003 Wow Thanks for all the good advice. I already changed the oil but I think the starter is shot. It engages but no torque. The motor is a Briggs I/C series 16 twin w/cast iron sleeves. If that helps anyone. Thanks again. Ill keep you posted .....Scot
Charlieson Posted August 7, 2003 Posted August 7, 2003 your float stuck open allowing the gas to continually drain into the crankcase. Install a inline fuel cutoff and turn it off after you finish mowing (all yea, fix your float). But the cutoff will insure that this wont happen again. ddh
pleco01 Posted August 7, 2003 Posted August 7, 2003 There is virtually no way for the gasoline to leak from any carb problem into the crank case and mix with the engine oil in a normal, functioning engine. The systems aren't even connected, save for the cylinders/ingnition system. Based upon my auto and small engine experience, I'd have to suggest you've got either a bad(stuck)valve, or a set of blown cylinder rings. this would allow gasiline to move from the cylinder into the engine case. The cylinder rings may be the culprit, but this isn't something that would occur suddenly, as rings deteriorate over time, and you'd notice poor performance from the engine. If the rings did die suddenly, it would likely ruin the engine with really hot, sharp shreds of metal grinding the inner cylinder walls...very bad news. If it's the valves, you'd notice poor compresion in the cylinder that's affected. Pull one plug, put your thumb over the hole and turn the engine, see if you feel a vacuum or outward pressure created...check all cylinders in the same way. stay with the same hole test till you feel both the vacuum and pressure, as it could be either the intake or exhaust valve in either cylinder. That's my nickle's worth, good luck with that engine...no matter what... is sounds lie it's gonna need a bit of work Pleco01
Leroy Posted August 7, 2003 Posted August 7, 2003 Pleco01. You have a good suggestion on compression check. But a float that does not shut off the fuel supply to the carb can continue to flow via gravity to the valve stems then down the piston cylinder past the rings and mixing thorouly with the oil.
pleco01 Posted August 7, 2003 Posted August 7, 2003 Leroy, I'll have to take your word for that, since that's not something I've ever seen or heard of. Although, I'm not a small engine expert. My understanding of the fuel system was that the fuel was turned into vapor when mixed with air in the carb. Then pulled (not pushed) into the cylinder during the intake stroke. So, since I'm a logical kind of guy, I've never imagined that the fuel could collect inside a cylinder during stand-still periods, since there's no vacuum to suck the fuel into the system. But like I said, I'll happily conceed that I may not know everything. Don't let me wife and kids know that tho' Pleco1
Charlieson Posted August 7, 2003 Posted August 7, 2003 Leroy's right. I've seen it at the shop many times. I've never seen it on an engine with a fuel pump though. Chances are the diaphram is bad on the pump. I've seen cars do this when they used to have mechanical fuel pumps on them. Since the gas tank is higher than the carb on gravity systems, if the float sticks open it will fill the crankcase. But if he has a two cylinder with a fuel pump I'll bet the farm that the fuel pump is bad. ddh
AGCO918 Posted August 7, 2003 Posted August 7, 2003 Had the problem on my Agco918 1999 model 2 yrs ago and it was the diaphram in the fuel pump as stated.Had it happen 2 or 3 times.Dealer ,was on the phone with Kohler everytime it happened and had a kohler rep look at the tractor ,came to the conclusion that it was the fuel not shutting off as everyone has stated on here due to the diaphram and the solinoid on the carb was also replaced with the carb itself rebuilt 2 or 3 times from all the oil and gas mixing and might have had a new carb put on it.MY dealer helped me out a bunch and ,he was told by kohler to put gas stabilizer in it if tractor is not to be running for a period of time and i go to walmart and buy a bottle of it every since then and have never had any problems since with tractor.It tells on the bottle how much to add to your gas.My Agco918 is 3 gals ,so i put a ounce or better,whatever it says on bottle , .This was directily from kohler ,so hope this helps out.I learned from this problem, the hard way ,happened to many times to me,so please use the gas stableizer and you shouldnt have any problem after you fix the carb and or pump. AGCO918
pleco01 Posted August 7, 2003 Posted August 7, 2003 Agco, Sounds like good preventative medicine, I think i'll get some of that and keep it on hand Pleco01
HubbardRA Posted August 7, 2003 Posted August 7, 2003 I had an 11 Hp B/S vertical shaft that filled the crankcase on me at least 3 times. Each time I took the carb apart and could find nothing wrong. The last time, it happened while mowing. The crankcase vent hose attaches to side of carb near the venturi and will let the gas drain into the crenkcase before it fills high enough to go into the cylinder. I'm not sure if this can happen on a 2 cylinder, but they can drain directly into the cylinder.
MoAC610 Posted August 8, 2003 Posted August 8, 2003 I hope some of the suggestions have helped I personally have run up against that problem. Two things can happen in the field it is called Leak Down. If you have a fuel pump check the Diaphram if it is good then go right to the Carb and look at the needle and seat. The needle is not closing and alows fuel to seap into the venturie. The fuel has no where to go except past the valves and into crankcase. If it happens DO NOT TRY TO START ENGINE until corrected. I have seen engines break in half or Bend connecting rods and snap camshafts. Briggs had tried to correct these problems by adding electric solenoids Hope it helps and good luck
Scotmo Posted August 9, 2003 Author Posted August 9, 2003 Thanks again all! It was the diaphragm. I will start another thread because I am done with Briggs diaphragm fuel pumps. I want to change over to an electric fuel pump. I have two 6216's and have had more than my share of diaphragm trouble.Some things are just not meant to be. If anyone has done this I would love to hear what parts you used and how you like it. Thanks everyone.....You guys are the best.......Scot
MPH Posted August 9, 2003 Posted August 9, 2003 Scot, for whats worth for your briggs, a 3-5 psi Puraltor pump from NAPA works really sweet on the Onan in my 4040. Hot wire, think it was red, goes to switched power, in my case pos. side of coil, other one to ground, route fuel line to proper ends, install new filter and you should be good to go. Sorry I can't be more spec, but haven't a clue as to how your 6216 is set-up..MPH
Scotmo Posted August 9, 2003 Author Posted August 9, 2003 Thanks Martin. I just started another thread. You always come through. the 3-5 psi was what I was looking for.... Thanks again....Scot
patrician12 Posted August 9, 2003 Posted August 9, 2003 Just got back from vacation and miss you guys.I think it is definitely the fuel pump.Every time I ever saw a carb"load up" there was always external leakage to go with it.Even on an automobile mechanical fuel pump leakage can occur into the crankcase and not show any signs of external leakage until the diaphragm is so punctured it will pump gas out the weep hole on the side.It is a tough diagnosis but a situation that is known from sheer experience.
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