Blown Engine - Looking for Ideas!

[billymagg]

Thanks. I called and spoke with them. They didn't have the right motor available. After a lot of research and reading multiple forums I decided to take the mower to a local "Scag" dealer and they dropped a new Honda motor in it for me. As it turned out they had to completely modify the muffler, get a new wiring harness, a bunch of new relays etc etc. to get the new motor to work. After (4) weeks its done now. And we're back in the saddle. Thanks for all your suggestions. It was helpful.

Glad to hear that you are back in the saddle, being nosy, 1600 bucks or so or North of that??? I think the new Honda will give you good service, the Kawasaki is touted by a kid at church as "bullet proof", he works for John Deere in the shop, and used to be the mower guy, all big stuff now. He is no fan of Briggs, and warned me that if I bought one, I would be in the shop, sooner or later with a hole in the side of the block.....

 

[Tree & Lawn Care]

Glad to hear that you are back in the saddle, being nosy, 1600 bucks or so or North of that??? I think the new Honda will give you good service, the Kawasaki is touted by a kid at church as "bullet proof", he works for John Deere in the shop, and used to be the mower guy, all big stuff now. He is no fan of Briggs, and warned me that if I bought one, I would be in the shop, sooner or later with a hole in the side of the block.....

Yes, the motor was $1600 plus $100 shipping, $400 for installation and incidental plus tax = $2,300 total but I now have a new machine, with new tires & belts etc that should last a while. The Scag is very well built. I have never had a problem with the frame or spindles or hydraulic pumps, etc. Overall, I feel its a very solid machine.

 

[motoman]

Great discussion, all, and thanks.

Mackie, you skipped over the short to ground phenomenon rather quickly. Since many read the posts clarify for them , please. I believe you may be referring to the idea of "stray current" which can set up corrosion and stress cracks on metal surfaces. So as current returns it kind of does what a plating tank does in reverse. Removes material . In this case crank journal surfaces, reducing oil clearance and oil pressure, and weakening hardened surfaces, eventually taking down parts which depend upon lubrication. I thought Honda (?alone) used a low oil warning light?

Once again I will suggest manufacturers should (?return) to equiping their (especially air cooled) engines with oil pressure gauges or warning light. Even if they argue..."Why , no one looks at them." On my lowly dyt4000 I can even tell if oil is below full by watching the 35-40 psi drop a little. And an oil temp gauge is very good as you can observe oil temp rise with various loads put on the machine. The handy man can install an oil pressure gauge for less than $50 (electric) and a couple hours.

 

[gfp55]

I just blew the motor on my 2004 Scag Tiger Cub 52" 24HP (Honda) ZTR today. I bought this machine ten years ago and have changed the oil regularly, kept it well maintained but for some reason the engine blew a hole in the side this afternoon. Looking for ideas as to where to go from here. As I've read this forum, I can either replace it with another Honda motor or perhaps another brand. The dealer I work with (who used to be a Scag dealer) recommends putting a Kawasaki in it. I open for ideas.

How many hours was on the Honda engine before it puked? I didn't read any hours on your posts maybe I missed it. I'm glad you got your machine back on the job.

 

[Tree & Lawn Care]

How many hours was on the Honda engine before it puked? I didn't read any hours on your posts maybe I missed it. I'm glad you got your machine back on the job.

I purchased the Scag in 2004, it had 2,100 hours before it blew. I've kept it maintained as well as possible, oil changes, new spark plugs, oil filters, fuel filters, valve adjustments, etc. but it still died after 2000 hrs.

I've since been told by the mechanics that worked on this machine that you are not suppose to shut the motor off while its running full throttle. I've never paid attention to this...so that fact no doubt played a factor in its demise. I now shut the throttle all the way down to an idle before turning it off. Its one of those things, if only I had known then what I know now.

 

[billymagg]

Yes, the motor was $1600 plus $100 shipping, $400 for installation and incidental plus tax = $2,300 total but I now have a new machine, with new tires & belts etc that should last a while. The Scag is very well built. I have never had a problem with the frame or spindles or hydraulic pumps, etc. Overall, I feel its a very solid machine.

That's not to bad, and with only 2100 hours, you should be good for at least another 10 years, we have a freedom Z at the campground with a 30 horse Kawasaki. We replaced one of our John Deere F935s and kept the other, the John Deere works better on some of the very steep hills around a small lake and pond dam. The Scag has given me several thrill as it will suddenly lose its footing and head down the hill, it is considerably lighter, and just doesn't seem to have the grip. I am contemplating filling the rear tires with fluid for a little more weight and traction. Overall I would say we are very happy for the money we spent so far.

Also a great idea to replace the tires and belts while it was down, that will no doubt save you some future down time.

 

[Tree & Lawn Care]

That's not to bad, and with only 2100 hours, you should be good for at least another 10 years, we have a freedom Z at the campground with a 30 horse Kawasaki. We replaced one of our John Deere F935s and kept the other, the John Deere works better on some of the very steep hills around a small lake and pond dam. The Scag has given me several thrill as it will suddenly lose its footing and head down the hill, it is considerably lighter, and just doesn't seem to have the grip. I am contemplating filling the rear tires with fluid for a little more weight and traction. Overall I would say we are very happy for the money we spent so far.

Also a great idea to replace the tires and belts while it was down, that will no doubt save you some future down time.

I've actually heard of other's doing this. They fill their back tires with the antifreeze that goes into winterizing RV's. They say it does give the mowers more stability.

 

[Mad Mackie]

Great discussion, all, and thanks.

Mackie, you skipped over the short to ground phenomenon rather quickly. Since many read the posts clarify for them , please. I believe you may be referring to the idea of "stray current" which can set up corrosion and stress cracks on metal surfaces. So as current returns it kind of does what a plating tank does in reverse. Removes material . In this case crank journal surfaces, reducing oil clearance and oil pressure, and weakening hardened surfaces, eventually taking down parts which depend upon lubrication. I thought Honda (?alone) used a low oil warning light?

Once again I will suggest manufacturers should (?return) to equiping their (especially air cooled) engines with oil pressure gauges or warning light. Even if they argue..."Why , no one looks at them." On my lowly dyt4000 I can even tell if oil is below full by watching the 35-40 psi drop a little. And an oil temp gauge is very good as you can observe oil temp rise with various loads put on the machine. The handy man can install an oil pressure gauge for less than $50 (electric) and a couple hours.

Just got home from an OH/PA railfan trip!
Although not common, the electric coil in a clutch can develop a short thru its insulation that can travel to ground thru the crankshaft, the main bearings and possibly the connecting rods. When this happens, the current draw in amps increases due to a decrease in the resistance of the coil and as this passes into the crankshaft, it will take the path of least resistance either into the connecting rod and or main bearings. In either case, particularly the connecting rods, the bearing surfaces of the rods can deteriorate quickly as they are usually aluminum. This will cause decreasing oil pressure and eventually engine failure. I have # 8 bonding wires on the clutches on two of my three machines. These bonding wires/cables have to be installed so as to not interfere with the V belt travel and replacement. I just went looking for the pics of the clutch bonding cable on my Ingersoll, but I didn't find them. I don't have a pic of the bonding cable on my Scag.
Mad Mackie in CT :laughing::biggrin::smile:

 

[Fish]

Yeah, but any way, this thread is about a 10 year old commercial engine....