Jump to content
68 raider 12

No compression, maybe broken connecting rod

Recommended Posts

68 raider 12

Hello, I was mowing my lawn today with my 68 raider 9/12 ( not sure exactly what year no accurate serial numbers to work with) everything was going smooth and then the engine started to kinda sound like it was struggling then quit and a little smoke puffed out of the air intake. I thought I had blown the engine so I gave it one last turn of the key and it fired up no problem but when I got it up to mowing rpm the engine made a horrible clunk noise and just shut off. The engine still turns over freely but almost to free and now seems to have no compression. Any thoughts? Thanks. 

Share this post


Link to post
Share on other sites
 
daveoman1966

Not sure...  Could be connecting rod or something else.  I have a good connecting rod for the Kohler K301 engine...you can have it for $25...SHIPPED.  I don't have the lower end cap for it.  Aluminum Connecting Rod and Wrist Pin here. 

k301 rod 007.JPG

k301 rod 004.JPG

k301 rod 002.JPG

Share this post


Link to post
Share on other sites
 
squonk

Most likely broken rod and tore up crank. And possibly a cracked cylinder wall as well. Tore 2 k301's apart this spring with cracked blocks

Share this post


Link to post
Share on other sites
 
68 raider 12
5 hours ago, squonk said:

Most likely broken rod and tore up crank. And possibly a cracked cylinder wall as well. Tore 2 k301's apart this spring with cracked blocks

I don't thing the crank, when I turn the engine over the flywheel spins and the shaft connecting to the pulley for the deck it all spins smooth, it just seems like the piston isn't moving so it won't fire.

Share this post


Link to post
Share on other sites
 
squonk
1 minute ago, 68 raider 12 said:

I don't thing the crank, when I turn the engine over the flywheel spins and the shaft connecting to the pulley for the deck it all spins smooth, it just seems like the piston isn't moving so it won't fire.

The crank will most likely be torn up where the rod used to be connected to it.

 

sj4.jpg.5ec23166a706957251039cc5a1e1a872.jpg

 

sj3.jpg.cfdcfd0811ed92a7e289fbab810cec9e.jpg

  • Like 2

Share this post


Link to post
Share on other sites
 
pacer
7 hours ago, 68 raider 12 said:

was struggling then quit

 

That right there was your - usually - early warning signal! That almost always is the engine seizing, --- low/out of oil, clogged cooling fins, etc, its got so hot that it seizes! By restarting it and then.....  

8 hours ago, 68 raider 12 said:

horrible clunk noise and just shut of

 

And as you are guessing, its probably got some serious damage now. If it was caused by clogged fins, then there would be a chance it might survive after cleaning them, but its usually worn parts. It turns because the rod/piston is probably totally destroyed.

 

Break out the wrenches!!

  • Like 1

Share this post


Link to post
Share on other sites
 
Handy Don
10 minutes ago, pacer said:

Break out the wrenches!!

And prepare wallet for discharges....

  • Like 1
  • Sad 1

Share this post


Link to post
Share on other sites
 
Gregor

Don't forget the camera. :banana-gotpics:

Share this post


Link to post
Share on other sites
 
68 raider 12
31 minutes ago, Handy Don said:

And prepare wallet for discharges....

I've found rebuild kits online for 124 so not to bad

Share this post


Link to post
Share on other sites
 
squonk

Don't order a thing until it's all tore down. If the block is busted, find another engine.

  • Like 3

Share this post


Link to post
Share on other sites
 
oliver2-44

 

29 minutes ago, squonk said:

Don't order a thing until it's all tore down. If the block is busted, find another engine.

You also may need to have the engine cylinder bored and the crank ground.

 

1 hour ago, 68 raider 12 said:

I've found rebuild kits online for 124 so not to bad

Then you would need the kit with the oversize piston and undersize rod.

 

  • Like 2

Share this post


Link to post
Share on other sites
 
68 raider 12
47 minutes ago, oliver2-44 said:

 

You also may need to have the engine cylinder bored and the crank ground.

 

Then you would need the kit with the oversize piston and undersize rod.

 

How would I know if the block is busted?

Share this post


Link to post
Share on other sites
 
oldlineman

Visual inspection, should be obvious. Bob

Share this post


Link to post
Share on other sites
 
68 raider 12
14 minutes ago, oldlineman said:

Visual inspection, should be obvious. Bob

Something that can be seen from the outside? Or is that on the inside of the engine? 

Share this post


Link to post
Share on other sites
 
squonk
2 hours ago, 68 raider 12 said:

Something that can be seen from the outside? Or is that on the inside of the engine? 

Inside. look at that picture I posted. Rod hits the cylinder wall

Edited by squonk

Share this post


Link to post
Share on other sites
 
8ntruck
2 hours ago, 68 raider 12 said:

Something that can be seen from the outside? Or is that on the inside of the engine? 

Most likely, the damage would be internal on the block.

 

You familiar with dye checking?  It might be worth purchasing a 3 can set of cleaner, dye, and developer.  Ought to be available at the local auto supply store.

Share this post


Link to post
Share on other sites
 
oliver2-44

If you don't see an external new hole in the block, that a small good start, but you also need to look inside.  With the oil pan removed are their any pieces of metal in the drained oil or bottom of the pan? Then, look up at the bottom side of the piston and cylinder.  Are any pieces of metal cracked along the bottom of the cylinder.  your looking for something like shown in the second picture.  

7 hours ago, squonk said:

The crank will most likely be torn up where the rod used to be connected to it.

 

sj4.jpg.5ec23166a706957251039cc5a1e1a872.jpg

 

sj3.jpg.cfdcfd0811ed92a7e289fbab810cec9e.jpg

  Then unbolt the 2 bolts that hold the bottom rod cap around the crank.  The crankshaft round journal should look very smooth and shiny, not like the first picture. 

Take pictures of anything you find in the oil/oil pan and the bottom side of the cylinder and the crank journal and post them here for us to help you look at them. 

This will help determine how you move forward.  I.e. a scrap block or a trip to the machine shop for precision measurements.  If the machine shop see's anything questionable crack wise, they should have the stuff on hand to do a 'Dye Check"  for invisible cracks.

  • Like 2

Share this post


Link to post
Share on other sites
 
John2189
19 minutes ago, oliver2-44 said:

If you don't see an external new hole in the block, that a small good start, but you also need to look inside.  With the oil pan removed are their any pieces of metal in the drained oil or bottom of the pan? Then, look up at the bottom side of the piston and cylinder.  Are any pieces of metal cracked along the bottom of the cylinder.  your looking for something like shown in the second picture.  

  Then unbolt the 2 bolts that hold the bottom rod cap around the crank.  The crankshaft round journal should look very smooth and shiny, not like the first picture. 

Take pictures of anything you find in the oil/oil pan and the bottom side of the cylinder and the crank journal and post them here for us to help you look at them. 

This will help determine how you move forward.  I.e. a scrap block or a trip to the machine shop for precision measurements.  If the machine shop see's anything questionable crack wise, they should have the stuff on hand to do a 'Dye Check"  for invisible cracks.

My 16 hp broken rod. It had a chunk out of the skirt of the cyl like the second pic. Looked like it would not hurt anything, the crank was good so I bought a new rod and rings for it and put it together. Runs great. 

  • Like 1

Share this post


Link to post
Share on other sites
 
squonk
11 minutes ago, John2189 said:

My 16 hp broken rod. It had a chunk out of the skirt of the cyl like the second pic. Looked like it would not hurt anything, the crank was good so I bought a new rod and rings for it and put it together. Runs great. 

You got lucky. Cylinder wall could have had a microscopic crack that would have ruined you day.

  • Like 2

Share this post


Link to post
Share on other sites
 
adsm08
6 hours ago, oldlineman said:

Visual inspection, should be obvious. Bob

 

I was scrolling and read this as "vivisection", which is seemingly equally appropriate at this point.

  • Like 1

Share this post


Link to post
Share on other sites
 
Howie

My K301 has been running with a chunk out of the bottom of the cylinder since

about 1985.

Share this post


Link to post
Share on other sites
 
squonk

Everyone who would run this block, raise their hand! :greetings-wavegreen:

 

IMG_20210416_142136365.jpg.a8e42184426c9d8e78bec3e4da479f78.jpg

 

 

  • Haha 1
  • Sad 1

Share this post


Link to post
Share on other sites
 
953 nut
On 7/13/2021 at 9:44 AM, 68 raider 12 said:

I've found rebuild kits online for 124 so not to bad

First things first.   Before you buy anything you need to find out what has happened. Disconnect and cap the fuel line, remove the choke and throttle cables and unhook all wires going to the engine. Now remove the four bolts that attach the block to the oil pan and take a close look.   :wwp:      You can remove the two bolts that retain the connecting rod (if they aren't already broken) and remove the cylinder head. Now you can take a closer look at the crankshaft and cylinder.     :wwp:           DON"T BUY ANYTHING until you KNOW what you need!

  • Like 1
  • Excellent 1

Share this post


Link to post
Share on other sites
 
squonk

Since it quit once and fired it back up so it would quit again it probably will look like this! 

 

IMG_20210416_142015797_HDR.jpg.7d337d71ed247314137872a6a7795d7f.jpg

 

 

  • Thanks 1
  • Sad 1

Share this post


Link to post
Share on other sites
 
Mickwhitt

Ouch!  Yes sounds like you will have a kit of parts for a con rod rattling round in the oil pan (sump).

Easy check is to take out the spark plug and see if the piston is moving up and down.

If not take off the head, see how things look in the cylinder.  You might be able to pull the piston out but it would take a bit of ingenuity to do that. You could then see the damage to the con rod then. That is when you will be removing and stripping the unit. 

Good luck. 

 

Share this post


Link to post
Share on other sites
 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...