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Blown Engine - Looking for Ideas!

#1

T

Tree & Lawn Care

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.


#2

D

dnewton3

Odd that a Honda blew a hole in the side. What caused the catastrophic failure? Over-revving? Bad rod? Dumb luck?


Generally, any decent engine from Kaw, Koehler, B&S, Honda can be used as long as you use the right crankshaft configuration.

Most all the engine brands have a slightly differnt wire harness set up, so when you view the Scag manuals, they each will have unique adaptors for the connector. But rest assured, they all achieve the same task. You can use the Scag manual to even make up your own jumper harness from one brand to another! My point is that if you select something other than an exact replacment, it will not be a simple "plug and play" situation. However, it's not really that hard to get into alternative brands AS LONG AS YOU KNOW HOW TO READ AND WIRE BASIC ELECTRONICS. If you don't, then find someone who can.

Here's a great place to get new engines for cheap. They get most of their stuff from production over-runs or close-outs.
Home - Small Engine Warehouse

Just put in the criteria you want and narrow it down
For example, put in:
gas engine
vertical shaft
1" shaft
2 cylinder
HP desired
etc, etc

Again - make sure to use the criteria from your engine (shaft size, etc) so that the new engine will match up to the PTO clutch; shaft size is probably the most critical to match up as most other stuff can be modified to accomodate. Even if the chassis holes are not lined up (which would be rare as most are universally used) it's easy to drill some new mounting holes. Make sure to pick one that has a charging system adequate for your electric PTO, if applicable. Some engines only have smaller stators for battery charging and lights; these will often be seen as "5/3" or similar. But high amp draw apliances like the PTO would need 10 or more like 15 amps available. If you have questions, you can call or email their tech line for help selecting a motor.

Also, in your selection pay close attention to the muffler topic; some come with one, some don't. That would also make a difference between your Honda and some other brand.

While you had 24HP, I'm not convinced you could not get away with a bit less; that would open up options for you as well. Only you can determine how much HP you need; are you mowing at home or commercial; how many hours a day or week; how much heavy wet grass, how many hills, etc, etc

I have used them before and been pleased. However they are not the only game in town, and other sources offer similar choices, so it pays to shop around. Jackssmallengines would be another such source. And there are others ...

Bottom line is that you can repower your rig for less than a $grand if you're not too picky, and able to do some of your own work (or find a buddy that will work for beer/pizza!).

That should get you headed in the right direction.


#3

T

Tree & Lawn Care

Odd that a Honda blew a hole in the side. What caused the catastrophic failure? Over-revving? Bad rod? Dumb luck?


Generally, any decent engine from Kaw, Koehler, B&S, Honda can be used as long as you use the right crankshaft configuration.

Most all the engine brands have a slightly differnt wire harness set up, so when you view the Scag manuals, they each will have unique adaptors for the connector. But rest assured, they all achieve the same task. You can use the Scag manual to even make up your own jumper harness from one brand to another! My point is that if you select something other than an exact replacment, it will not be a simple "plug and play" situation. However, it's not really that hard to get into alternative brands AS LONG AS YOU KNOW HOW TO READ AND WIRE BASIC ELECTRONICS. If you don't, then find someone who can.

Here's a great place to get new engines for cheap. They get most of their stuff from production over-runs or close-outs.
Home - Small Engine Warehouse

Just put in the criteria you want and narrow it down
For example, put in:
gas engine
vertical shaft
1" shaft
2 cylinder
HP desired
etc, etc

Again - make sure to use the criteria from your engine (shaft size, etc) so that the new engine will match up to the PTO clutch; shaft size is probably the most critical to match up as most other stuff can be modified to accomodate. Even if the chassis holes are not lined up (which would be rare as most are universally used) it's easy to drill some new mounting holes. Make sure to pick one that has a charging system adequate for your electric PTO, if applicable. Some engines only have smaller stators for battery charging and lights; these will often be seen as "5/3" or similar. But high amp draw apliances like the PTO would need 10 or more like 15 amps available. If you have questions, you can call or email their tech line for help selecting a motor.

Also, in your selection pay close attention to the muffler topic; some come with one, some don't. That would also make a difference between your Honda and some other brand.

While you had 24HP, I'm not convinced you could not get away with a bit less; that would open up options for you as well. Only you can determine how much HP you need; are you mowing at home or commercial; how many hours a day or week; how much heavy wet grass, how many hills, etc, etc

I have used them before and been pleased. However they are not the only game in town, and other sources offer similar choices, so it pays to shop around. Jackssmallengines would be another such source. And there are others ...

Bottom line is that you can repower your rig for less than a $grand if you're not too picky, and able to do some of your own work (or find a buddy that will work for beer/pizza!).

That should get you headed in the right direction.

Thank you for the information. I don't know what happened. I purchased this mower brand new back in 2004 and have maintained it regularly since I bought it. I use it in my lawn care business, in a commercial application. We probably put between 15 - 20 hours a week on that machine. I had just changed the oil and oil filter, spark plugs, fuel and air filters. I was just mowing a long as usual when it puked. Started to shutter, and stalled. I looked back to find oil spraying out the side along with a lot of smoke. My son came over, looked at it and said, "Is that hole in the side of the motor supposed to be there?

It was interesting because when I called the dealer they told me these motors (Honda) typically only last about 2000 hours. I was surprised to hear this. I would have thought they would go a lot longer than that, although I don't have a frame of reference, this is the first and only ZTR I've owned.

After having looked at several forums, I'm leaning towards purchasing another new or used Honda motor and installing it myself with a friend that knows a lot more about electrical schematics than I do. I do know that common sense and patience gets you a long ways, but its always nice to have a friend help that knows more than I do about these things. I'll pay attention to the specs as you've mentioned to make sure I order the right motor. Thanks for your input, its been helpful.


#4

I

ILENGINE

Be aware that Honda did a rework of there twin engines about 5 years ago. Basically went to a semi hemi head type system, and consolidated blocks. Your old exhaust may not fit a new Honda, because the mounting angle has changed.


#5

T

Tree & Lawn Care

Be aware that Honda did a rework of there twin engines about 5 years ago. Basically went to a semi hemi head type system, and consolidated blocks. Your old exhaust may not fit a new Honda, because the mounting angle has changed.

Thanks for the information. So, can one assume those engines are better as a result of the modifications? Can one expect to get more than 2000 hours before it blows? Having never bought a new engine, what comes with the engine? Does the carburetor come with it, etc.?


#6

I

ILENGINE

The main differences in what engines come with will be with or without air filter, with or without muffler, with or without fuel tank. the model consolidation within Honda was 6 blocks changed to 2. Also they changed from a open to run igntion system to a closed to run ignition system, which if that is the case will also require replacing the ignition switch.


#7

M

Mad Mackie

New engines come complete, but a muffler, control cables, electrical changes, fuel line changes may be needed.
Look thru Small Engine Warehouse, Tulsa Engine Warehouse and others to see what is available. Depending on the crankshaft dimensions of your Honda, you may be able to repower with a Briggs Vanguard in the 20-23 HP range for a reasonable price.
I repowered my 2008 Tiger Cub from a 26 Briggs ELS engine to a 30 Briggs Professional Turf series engine. The engines being similar made the repower easy, same muffler, same cables, same electrical connector, no fuel system changes. A crankshaft size of 1 1/8" X 4 5/16" will limit your options.
As has been mentioned, the crankshaft size is critical to a repower, with an exhaust system being next.
As with any repower, there are hidden extras that always show up!!! I suggest that you replace the electric clutch as you repower your machine. Although rare, when a clutch develops a short to ground but still operates, the path of least resistance is into the crankshaft, the engine bearings, then to the engine block ground. When this happens, a major internal engine failure will happen. This happens more often than most realize as it usually is misdiagnosed. I reinstalled my original clutch as it checked out, however I have spare clutches in my parts stash for all my machines that have electric clutches. The downside to stocking clutches is the warranty expires 12 months from the purchase date to a retail purchaser. Having had to replace electric clutches in the middle of a snowstorm, I'll take the risk of expired warranty!!!
Mad Mackie in CT :laughing::biggrin::smile:


#8

B

brianslawncare

Try small engine warehouse.


#9

T

Tree & Lawn Care

Try small engine warehouse.

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.


#10

D

dnewton3

I find it odd they had to go through so much rework; revise muffler, new harness, relays, etc ...
That's exactly the kind of work you'd have to do yourself had you go the engine from a discount house like the ones we suggested.

Regardless, if you're happy with the result, that's all that matters.


#11

B

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.....


#12

T

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.


#13

M

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.


#14

gfp55

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.


#15

T

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.


#16

B

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.


#17

T

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.


#18

M

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:


#19

Fish

Fish

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


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