Flint_Fredstone
Forum Newbie
- Joined
- May 29, 2020
- Threads
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- 3
Neighbor gave me a riding mower. I asked what was wrong with it. This is their story. (Troy built Pony with a briggs/stratton Intek 17.5hp single cylinder)
70 year old woman owned this mower, son helped her maintain her stuff but he is definitely not mechanically inclined (can't fix nothing mechanical) apart from changing the oil with whatever the dollar store has.
Whats wrong with this mower you ask? "Well I don't really know" she said, "my son had someone to look at it and they said it was the cam pin". (what?)
Me: Cam pin?
Yea, he was mowing with it and hit a metal spike, stopped the engine completely. After that, it wouldn't ever start back.
I thought I knew what was wrong with this "free to a good home" mower. Simple as replacing the flywheel key I mistakenly thought. I had seen this many times on a push mower, not so much on a riding model.
I consider myself to be a very skilled person when it comes to tinkering on stuff. I fix my cars, my house, and yes my mowers.
Trying to fire this thing up without doing anything, the starter cranked this engine surprisingly well. It would "hit" about once every 10 revolutions or so. Just a "pow" out of the the exhaust when pouring fuel directly down the carb. I thought it was firing out of time due to sheared flywheel key.
First thing is first. Air/Fuel/Ignition. At the right time in the right amount. Got it.
First I checked the flywheel key. (uh oh) Its good.----- Second I checked spark. I had spark but this rusty flywheel and rusty coil was giving me yellow fire no matter how much I adjusted or sanded/cleaned up with new known good spark-plug. Ok, I need a coil.
I replaced the coil and just like that I had a pretty blue spark. --- Still as first try though. Pow out of the exhaust every 10 revs or so.
This is when I found out that this engine has many "faults". Pushrods either bending or breaking, cams wearing out, etc. I basically now consider this thing junk and not worth fixing due to the problems encountered with these engines. But If I can get it to run reliably I'm all in if I can do this repair on the cheap, which I think I can due to what I found.
Help me figure this one out.
Intake push rod bent like a banana. I instantly checked my valve guides and they were still well seated. I depressed the valves by hand and they are smooth as silk with no binding. They seal very well with no burned spots or much carbon buildup.
There were some carbon deposits inside the intake runner just above the intake valve which means to me that at some point the intake was sticking. Is this a true assumption on these engines or could that just be from the heat carbonizing the oil mist from the crankcase vent?
I would think at some point the son had someone to look at it, they saw the push rod off the rocker, moved it into position and tried to get them in spec. When that didn't work, they gave up. They must have just said "cam pin" and told the woman its too expensive to fix.
Here is my question. Push-rods don't bend for no reason. What bent this one? Had to be a sticky valve or the clearance opened up enough to let the rod slip out of its pocket correct?
The valve cap was missing on the exhaust side and had way too much clearance. I would say the clearance opened up and dropped a rod. The exhaust wasn't too far behind.
The woman said she only mowed with it twice and by looking at the tires and the condition of the piston, which by the way HAD NO IMPACT MARKS from hitting a valve, this mower has at least 60 hours on it. It was used way more than twice.
I know my best bet would be to remove the valves and clean them up but its not worth that much to me. I'm willing to replace the rod, head gasket, cover gasket and do the labor.
Do you guys think when I replace the rod it will just bend again? Whats the chances of sticking valve vs clearance opening up? I'm sure the cheapest gas available was uses as with the cheapest oil.
I could use a link to a good place to look up part numbers. Intek Model: 31c707---------Type: 0154e1 and another number my have been scraped off.. unreadable.
Thanks in advance and hope you enjoyed the read.
70 year old woman owned this mower, son helped her maintain her stuff but he is definitely not mechanically inclined (can't fix nothing mechanical) apart from changing the oil with whatever the dollar store has.
Whats wrong with this mower you ask? "Well I don't really know" she said, "my son had someone to look at it and they said it was the cam pin". (what?)
Me: Cam pin?
Yea, he was mowing with it and hit a metal spike, stopped the engine completely. After that, it wouldn't ever start back.
I thought I knew what was wrong with this "free to a good home" mower. Simple as replacing the flywheel key I mistakenly thought. I had seen this many times on a push mower, not so much on a riding model.
I consider myself to be a very skilled person when it comes to tinkering on stuff. I fix my cars, my house, and yes my mowers.
Trying to fire this thing up without doing anything, the starter cranked this engine surprisingly well. It would "hit" about once every 10 revolutions or so. Just a "pow" out of the the exhaust when pouring fuel directly down the carb. I thought it was firing out of time due to sheared flywheel key.
First thing is first. Air/Fuel/Ignition. At the right time in the right amount. Got it.
First I checked the flywheel key. (uh oh) Its good.----- Second I checked spark. I had spark but this rusty flywheel and rusty coil was giving me yellow fire no matter how much I adjusted or sanded/cleaned up with new known good spark-plug. Ok, I need a coil.
I replaced the coil and just like that I had a pretty blue spark. --- Still as first try though. Pow out of the exhaust every 10 revs or so.
This is when I found out that this engine has many "faults". Pushrods either bending or breaking, cams wearing out, etc. I basically now consider this thing junk and not worth fixing due to the problems encountered with these engines. But If I can get it to run reliably I'm all in if I can do this repair on the cheap, which I think I can due to what I found.
Help me figure this one out.
Intake push rod bent like a banana. I instantly checked my valve guides and they were still well seated. I depressed the valves by hand and they are smooth as silk with no binding. They seal very well with no burned spots or much carbon buildup.
There were some carbon deposits inside the intake runner just above the intake valve which means to me that at some point the intake was sticking. Is this a true assumption on these engines or could that just be from the heat carbonizing the oil mist from the crankcase vent?
I would think at some point the son had someone to look at it, they saw the push rod off the rocker, moved it into position and tried to get them in spec. When that didn't work, they gave up. They must have just said "cam pin" and told the woman its too expensive to fix.
Here is my question. Push-rods don't bend for no reason. What bent this one? Had to be a sticky valve or the clearance opened up enough to let the rod slip out of its pocket correct?
The valve cap was missing on the exhaust side and had way too much clearance. I would say the clearance opened up and dropped a rod. The exhaust wasn't too far behind.
The woman said she only mowed with it twice and by looking at the tires and the condition of the piston, which by the way HAD NO IMPACT MARKS from hitting a valve, this mower has at least 60 hours on it. It was used way more than twice.
I know my best bet would be to remove the valves and clean them up but its not worth that much to me. I'm willing to replace the rod, head gasket, cover gasket and do the labor.
Do you guys think when I replace the rod it will just bend again? Whats the chances of sticking valve vs clearance opening up? I'm sure the cheapest gas available was uses as with the cheapest oil.
I could use a link to a good place to look up part numbers. Intek Model: 31c707---------Type: 0154e1 and another number my have been scraped off.. unreadable.
Thanks in advance and hope you enjoyed the read.