I have a Snapper 381450HBVE rear engine rider with 14.5 HP Briggs IC model #287707 engine that is getting on in years. It has been smoking off and on for the past season or two. I always top off the oil before I start it up. Lately it has been fouling plugs more frequently. Usually I can just pull the old plug out, clean it and she's good to go. Not so much anymore. The last time it died I put in a new plug, checked for spark it was good) and it still wouldn't start. It also doesn't sound normal when cranking. Kind of a "Wub,wub,wub" sound with the choke all the way closed and that goes away with choke opened so all you hear is the starter motor turning over. The Wub,wub,wub is almost a popping sound but not like it's trying to fire. So, I pulled the plug and checked compression. It is at 130 psi which is where it has always been at since I bought it 4 years ago. The plug is wet with gas when I pull it out. I'm wondering if there is a timing issue or maybe a problem with the valves. If that is the case I may just move on to a little bit wider zero turn which has always been my goal since buying this property. Just at an acre it's probably more that the Snapper likes to do. Any ideas on why it won't start? Or recommendations for zero turns?:biggrin:
Thanks Walt. I am trying to get that off right now but I am fighting the aluminum hub for the pull start mechanism. I assume that it is a press fit. I have a very weak puller that won't stay on good enouh to pull it. It did move maybe a sixteenth but now it won't budge. Is there a special tool or technique to get it off? I think that I'll just head out to HF and get a better puller. I am not noticing any play in the flywheel on the shaft but it could have moved just enough to mess up the timing I suppose and not have any play in it.
Is there a possibility that my valves are out of adjustment? I read in another forum that this is a common problem for a "no start" problem in B&S engines. One thing that makes me wonder about this is the compression release function that I didn't know this engine had. It has always been a hard starter and it would really slow down on compression stroke and sometimes run battery down before it would start. It is turning over now like it doesn't have compression (but it does). Could the compression release or valves be out of adjustment? Still looking for a decent puller for that flywheel.
OK, should have checked out the model number. Forget the flywheel for now at lest.By the way, IF this engine has a recoil (unusual for this engine) that recoil hub screws off normal right hand thread. Use wooden block against one of the ears and hit wood with hammer in direction to loosen.You need to remove the valve cover however. I suspect a valve has stuck and a push rod has come out or broken.
Contact me at address below and I will send you a Service Manual for your engine and Instructions for fixing a moved valve guide should that be the problem. Put in proper format and remind me engine model number and what you want (and what you have found)
You need to try to figure out WHY the rocker arm broke. IF you get the email I sent you, you will check the height of the valve guides. Let me know if one is high, should not be more than 1/8" above the head casting.
I got the e-mail yesterday. Thanks for that. I should be able to get it apart today and hopefully get parts by Monday or Tuesday. Not really clear on the valve guide mod but I assume that it is a common problem with the guides slipping. I just don't understand how cutting the groove fixes that. Maybe it will be more clear once I get into the repair.
Update: Finished tearing it down today. I found the valve guide on the exhaust to be 3/16" above the casting and the intake 1/4" above the casting. Also the intake pushrod is badly bent. Neither one of the valve guides seem to be loose but maybe that is something that is not readily seen. Additionally, I see that the intake valve guide is sticking down into the combustion chamber 5/16". If I lower the valve guide height on the spring side it is going to make the combustion side 7/8" Isn't that getting close to the top of the piston? I'm concerned about how that pushrod got bent and whether any other damage might have occurred.
"If I lower the valve guide height on the spring side it is going to make the combustion side 7/8" Isn't that getting close to the top of the piston? I'm concerned about how that pushrod got bent and whether any other damage might have occurred."
How is the valve guide going to get past the valve to get to the piston? I told you what B&S says about valve guide height. Of course the valve guide is not going to be "finger" loose. The push rod will bend for a couple of reasons. The aluminum intake valve push rod may wear a thin area where it rides on the fiber guide and be weakened until it bends. More likely the valve guide moves up until the valve spring keeper hits the top of the valve guide bending the push rod as it tries to open the valve. Occasionally the valve may stick causing the push rod to bend as it tries to open the stuck valve.
I solved the problem with a new head, valves, springs, guides etc. I couldn't find anyone local with the correct tooling (or desire) to do the job. I did find that the old valve caps were worn way down probably causing a severe valve maladjustment. It finally just shook itself apart bending the push rod and breaking the rocker.
One other question about the valve adjustment. I went by the service manual to set the valves and I'm pretty certain that they are correct. I turned the cylinder over and rechecked the settings 3 times. Problem that is bothering though is the torque value on the adjustment lock screw. I don't have an allen wrench bit that will fit on my torque wrench. How critical is the torque here? I would think that under-tightened would cause it to come loose. What is the consequence to having it too tight?
I may have to make a trip to town to pick up another tool.
OK, answering my own question; If it wasn't important there wouldn't be a torque value for it. I got a proper allen wrench to fit on my 3/8 torque wrench and re-did the lock screw. I actually think I wasn't too far off.
So, then I turned the key to start it up and it started right up. I was at first impressed but now I have a governor/speed problem. I can't get it to idle down at all. At first the linkage was jammed but I got it straightened out so the cable goes in and out properly and the choke lever closes. I can start it and control the speed with the throttle on top of the carb. If I push the governor linkage forward it will move the throttle lever and it appears that the spring is still hooked up correctly. I'm going to the manual but I thought that I would post the problem here also.
I found a bent throttle control rod, the one that connects the governor to the throttle valve. Straightened it the best I could and now it works correctly. Time to mow.
