147 Engine Rebuild
 

After setting the timing the correct way and still getting an engine knock, I decided to pull the engine for a rebuild. After tearing into the engine I saw some things and I have a few questions if you don't mind answering them.

1. My block has a few studs instead of all bolts for the head to be secured. Do you guys normally take out the studs before taking the engine to the machine shop or leave them in.

2. See piston pic. The piston top edge appears to have been chewed up by something and the bore was scratched heavy in this area. What would normally case this to happen, Carbon ?

3. The balance gears were really loose and flopped on the shafts. I am wondering if this is what was causing my knock. The connecting rod was not loose and felt good other than very slight play. I am going to leave the balance gears out when I put it all together but do I leave the shafts in or do they have to come out with the gears ? Thanks guys, Smoke

I remove all the studs.

Piston wear is "normal". Caused mostly by lean condition and carbon. Mainly running lean/hot.

Leave the balance gear shafts in.

Take the block and crank to the shop.

J-Mech, thanks for the info. do the studs normally come out easy or am I looking at throwing heat to them ? Also, on the top of the piston I couldnt find any numbers for size, all I could see was the letter B. What doe that stand for ? Thanks Smoke

Sometimes the come out easy, sometimes they done. I never use heat on the block unless it's the only option.

B is the second letter of the alphabet.

Could the B have been an F for flywheel/Piston orientation. They sometimes have an arrow also.

Did one of these big blocks a while back! Love the sound of it with a kids straight pipe!:) Good luck with the build.
Regards,
Chris

Hi guys, did some more checking on my engine in the 147 today. I think the engine may have been switched at some time and I don't think I have the K321 14 hp. I think I may have a 10 or 12 hp K. The exhaust valve measures 1-1/8 across and I think the K321 engines had a larger exhaust valve. Are their any other parts on the engine that I can check to see if this is a 14 or 14 hp specific parts. I am getting ready to order parts and would like to know what engine I am ordering parts for. The shroud tag is gone so I cant even start there. It does have the deep sump oil pan on the bottom and not flat. Not sure if that matters or not.. Thanks for your help. Smoke

Some K321 engines had a small exhaust valve. Odds are your has a small exhaust valve from the factory. Check the spec number. The big valve K321 spec number with a d.

The only way to see what what engine you have is to measure the cylinder. To order a rebuild kit you need to know the following:
cylinder bore diameter
crank journal diameter
connecting rod journal (big end) diameter
You need a Kohler service manual to rebuild your engine. It shows how to disassembled, what to check and how to rebuild your engine.

Standard bore for the K321 is 3.50" (3 1/2), K301 is 3.375 (3 3/8), K241 is 3.25" (3 1/4). The 321 is gonna have a bigger flywheel but I don't know the dimensions. Maybe someone else can help on that. Also, here is a valve chart from the book I am looking at....

Thanks guys, looks like its a 14 hp. I appreciate your comments.