Engine quit today, now no compression

[TheSaturnV]

Don't start buying parts until you get the thing completely stripped and have a machine shop MIC it. Most folks don't have the calibrated eyeballs to know when the cylinder has gone egg-shaped. They may advise anything from boring the cylinder to turning the crank down.

Get your facts gathered up front.

[Billy-O]

Originally Posted by john hall

I vote for #6

Well....if you had and one of the 1 thru 5 happen too you, number 6 is automatically included.

Number 4 is my bet.... had a smoker.... a bad smoker. Piston/rings sloppy loose. Worn. Look how much carbon/oil deposits on piston and heads already after a new head gasket in March.

Pull the bottom and have a look-see before doing anything. If things look good, the machine shop is your new friend!

[ccollins0601]

Originally Posted by olds45512

In my opinion if you going to buy new parts you should buy an oversized piston and have it bored, I don't think it's money well spent to buy a new piston and slap it in a worn out hole because it will just be a band aid repair.

I'm thinking the same thing. Either way, I am hoping to find time to tear into it this weekend and wil report on the status.

[bocephus1991]

Bag your ur parts and Take pictures so you know what goes where on the Engine.

[ol'George]

Originally Posted by bocephus1991

Bag your ur parts and Take pictures so you know what goes where on the Engine.

Funny how time changes a man----
50+ years ago I'd pull apart a small block chevy and throw the small parts in a 5 gal bucket of kero
some weeks later, maybe months, I'd wash parts and re assy knowing where each went just by the look of them or length/size.
Today, I can't remember what I had for B'fast or If I ate it!! Ha,LOL!
Enjoy youth guys, it is fleeting!

[J-Mech]

Originally Posted by ccollins0601

I was surprised to see the condition of the head - lots of carbon and crud, even though I had just decarbonized and replaced the head gasket in March. I only used it for mowing and light towing since then.

So now I'm wondering what could have caused the problem(s)? A few theories...

1. I got a new carburetor last winter, but the air filter didn't fit back on without interfering with the throttle linkage. I built a makeshift rubber gasket that I thought would provide some spacing and still keep it clean. When I took the filter housing off, it was really dirty and some of the dirt had gotten into the throat of the carb (sorry I forgot to take pictures before cleaning it).

You say you are surprised to see the carbon in the chamber, but after reading this #1 and looking at the pics, this is most of the cause of your carbon. Carbon is simply what's left behind that won't burn. Yes, oil can cause it, but so will dirt. From the looks of the pics, I can say for sure your engine was ingesting dirt. Did it cause your rod to fail? Very possibly. Did it excessively wear your cylinder? For sure.

Originally Posted by ccollins0601

2. I have a bunch of hills in the yard that used the cub to mow. I read somewhere this can cause lubrication problems. I had not been on any of the the hills the day the rod broke though.

It doesn't cause lubrication problems..... it is a lubrication problem. The engine is splash lubed off the dipper on the rod. If it doesn't have oil to splash because it's all hanging out in the corner from being tipped.... it's can't lubricate. Did it cause your rod to break.... I'm sure it didn't help. But not likely the cause.

Originally Posted by ccollins0601

3. Also with the new carb, the choke wouldn't fit on with the air filter. I ended up reversing the choke arm to get it to fit, maybe this screwed something up? I also had fiddled a good deal with the adjustment screws in the spring, I thought I had it sounding pretty good but don't have much experience so maybe it was too rich or lean.

The choke has to open and close all the way to do it's job. Did you adjust it correctly..... no way to know. From the looks of it, it looks a little rich.

Originally Posted by ccollins0601

4. The engine had been consuming some oil, I would have to add a couple oz. every 5-10 hours of use. The day it blew I had checked the oil it was about halfway between Full and Add. I didn't have anymore oil on hand and figured it was okay since it wasn't at Add.

Not likely any effect on what happened. Not unless it suddenly burned it all.

Originally Posted by ccollins0601

5. I did something wrong when I cleaned the head in March

Not likely at all the cause of rod breakage.

Originally Posted by ccollins0601

6. S**t happens.

All the time.

Originally Posted by ccollins0601

So two questions:
- what do you think caused this?
- what to do now - what skills/tools/time are involved in a rebuild, should I try it myself and if so where to start, or anyone recommend a shop in Mass who would do it? If so how much should I be looking to pay?

Most likely cause: Age

Should you do it yourself.... all here will likely say "YES" except me. I say NO. One should know what they are good at and stick with it. Can we all learn new things? Sure. Do you want to learn? Do you have the $$ to tool up and are you willing to accept what happens if you do it wrong? That's up to you to decide. I say pay someone. When I rebuild them, they wind up in the $6-700 dollar range. Give or take what the customer wants.

(Not that you will ask me, but no, I will not do it. I would like to get back into offering that service, but I am simply too busy right now.)

[Shrewcub]

Great post J!

This was my favorite!

Quote: ccollins0601
6. S**t happens.

All the time.

[J-Mech]

Originally Posted by Shrewcub

Great post J!

This was my favorite!

Quote: ccollins0601
6. S**t happens.

All the time.

It does too!

[ab147]

I just put a k321 on the floor from a 149 that's doing the same thing, I took another 321 from a 147 and put it in the 149 so I'll be able to use the snow blower this winter. Can't use the 147 for anything but towing as the electric lift is broken. Going to take the pan off and see what happened this week. I've had the 147 for about 20 years, and the 149 for about 5, and nothing has ever gone wrong, now they both break the same year. Oh well.

[ccollins0601]

I finally got the engine out and apart. Here's what it looks like. Looks like a chunk came out of the bottom of the cylinder. Is this engine rebuildable, or no good?