What could I be missing? Snowblower will not start
#1
01-20-11, 04:22 PM
What could I be missing? Snowblower will not start
Hello, I posted quite a bit of troubleshooting info a week or so ago regarding a Craftsman 536.881800 Snowthrower with an 8HP Briggs. Basically, I cannot get the thing to start for the first time this winter, after sitting for the summer. Here is what I have narrowed down.
1- it has clean spark. I put a new plug in and have viewed a strong blue/orange spark with a Air Gap Tester
2- Installed a new armature /coil today
3- has fresh gas. I also removed and replaced the fuel line, along with adding an in-line shut off valve
4- I removed the bowl, cleaned it, cleaned the nut (with small jet holes in it) that holds the bowl on, inspected the float which freely moves, and sprayed some carb cleaner in and around the bowl.
I have also done the process reccommended by a nice poster which involved removing the plug, holding the throttle on full with the gas off and choke open, and spun the engine over about 15 times. It spins freely with no compression obvisouly.
Then, I put a teaspoon of fresh gas in the spark hole, along with the new plug, half throttle and half choke and it does not quite want to fire. After a minute of trying, it will become harder to pull, or the starter labors more to turn the flywheel, even freezing up. It seems like there is so much compression in there it is hard to turn, or something like that. I can loosen it by slowing pulling, then I am back to square one. I cannot quite get it to fire and catch, or burn/combust any of the fuel.
I have also tried carb cleaner, and starter fluid in the spark hole and/or carb, thinking surely this will fire, and I will be in business- but nothing.
I really don't think it is flooded. I have tried this process so many times, and different times of the day, in different temperatures, and after sitting for a day or so sometimes.
I am wondering if I am going to need to rebuild the carb? I don't see how there could still be a vapor lock in there anywhere, but that is almost what it seems like. Or a varnish build up somewhere? For some reason, I just cannot get it to fire. I feel that if it does, it will likely burn any built up gunk out of there and I will probably be in business right?
The last thing that has me worried is all of the safety wiring. There is a plastic key near the primer bulb that basically gets in between a wire that is grounded to the unit, and a wire that runs out of the armature. Also, there is an on/off switch for the unit. I have tried every possibly combination, just in case some of the wires are on backwards or something. Is there a way I can rule out the wiring but unhooking it all, and just getting back to basic spark and fuel? I wonder if it would be tough to shut the unit down if it did start though....
Any idea at all? The only other bit of info is that there is a larger gauge red wire, with a cylindrical wire connector on the end of it, which sticks out near my electric start. I don't believe this has ever been connected to anything- it almost looks like a diagnostic hook up or something??? Not totally sure.
Any help would be appreciated. I am so close on this, I hate to take it into a shop for a simple fix. And yes, this will be the last time I forget to add Sat-Bil before storing it for the summer.
Thanks in advance
1- it has clean spark. I put a new plug in and have viewed a strong blue/orange spark with a Air Gap Tester
2- Installed a new armature /coil today
3- has fresh gas. I also removed and replaced the fuel line, along with adding an in-line shut off valve
4- I removed the bowl, cleaned it, cleaned the nut (with small jet holes in it) that holds the bowl on, inspected the float which freely moves, and sprayed some carb cleaner in and around the bowl.
I have also done the process reccommended by a nice poster which involved removing the plug, holding the throttle on full with the gas off and choke open, and spun the engine over about 15 times. It spins freely with no compression obvisouly.
Then, I put a teaspoon of fresh gas in the spark hole, along with the new plug, half throttle and half choke and it does not quite want to fire. After a minute of trying, it will become harder to pull, or the starter labors more to turn the flywheel, even freezing up. It seems like there is so much compression in there it is hard to turn, or something like that. I can loosen it by slowing pulling, then I am back to square one. I cannot quite get it to fire and catch, or burn/combust any of the fuel.
I have also tried carb cleaner, and starter fluid in the spark hole and/or carb, thinking surely this will fire, and I will be in business- but nothing.
I really don't think it is flooded. I have tried this process so many times, and different times of the day, in different temperatures, and after sitting for a day or so sometimes.
I am wondering if I am going to need to rebuild the carb? I don't see how there could still be a vapor lock in there anywhere, but that is almost what it seems like. Or a varnish build up somewhere? For some reason, I just cannot get it to fire. I feel that if it does, it will likely burn any built up gunk out of there and I will probably be in business right?
The last thing that has me worried is all of the safety wiring. There is a plastic key near the primer bulb that basically gets in between a wire that is grounded to the unit, and a wire that runs out of the armature. Also, there is an on/off switch for the unit. I have tried every possibly combination, just in case some of the wires are on backwards or something. Is there a way I can rule out the wiring but unhooking it all, and just getting back to basic spark and fuel? I wonder if it would be tough to shut the unit down if it did start though....
Any idea at all? The only other bit of info is that there is a larger gauge red wire, with a cylindrical wire connector on the end of it, which sticks out near my electric start. I don't believe this has ever been connected to anything- it almost looks like a diagnostic hook up or something??? Not totally sure.
Any help would be appreciated. I am so close on this, I hate to take it into a shop for a simple fix. And yes, this will be the last time I forget to add Sat-Bil before storing it for the summer.
Thanks in advance
#3
01-20-11, 06:55 PM
Check your oil level first. If Ok and you have the blue spark and obviously compression, it will start with the fuel added to the cylinder through the plug hole.
When you did the flooded condition starting, did you have the fuel shut off from the tank to the carb?
Do the flooded condition start again, but first shut off the fuel from the tank and drain the carb bowl then purge the cylinder of fuel with the plug out. Add the fuel and spin the engine over once, no more. Then proceed with the starting procedure.
It really sounds like a first start of the year headache. Once you have it started the first time you'll be OK.
When you did the flooded condition starting, did you have the fuel shut off from the tank to the carb?
Do the flooded condition start again, but first shut off the fuel from the tank and drain the carb bowl then purge the cylinder of fuel with the plug out. Add the fuel and spin the engine over once, no more. Then proceed with the starting procedure.
It really sounds like a first start of the year headache. Once you have it started the first time you'll be OK.
