18Hp Briggs twin rebuild

[sgtsampay 117]

Hello all. In case some of you don't know. I recently got a 1995 Briggs 16Hp 42ci (So its really a 18Hp model. from an old MTD lawn tractor. My ultimate plan is to take that engine and place it on my tractor to replace the old 11Hp briggs.

So, I started working on it Saturday. Well I had to pressure wash the outside first as it was very dirty and covered in old crude. I think took it off the tractor and put it on two saw horses.

I think tried to hock a battery up to it and see if it would turn. Well, nothing happened. So, I took the starter apart and found out that the led going into the start, where the battery connects, came un soldered from the cable inside. So, i resoldered it, and used JB weld to fix a little crack on the outside of the starter. Still didn't test to see if it works though..

I then hocked up a large electric drill to the fly wheel and then did a compression test on both sides. Well, the lower cylinder got 110psi and the top on got 0psi. (I thought great, I got a stuck valve..) So, i took off the head and had a super hard time getting it off, as I broke on of the head bolts. So that meant I had to place it on the drill press to drill out the bolt. Well, the engine was to large so I had to take the other head off to gain several ins to use the press. Well, i was able to get the bolt drill, so it all set now.

I then took a real hard look at the cylinders and saw a stuck valve in the top one, like I thought. It was carbonized stuck, so I sprayed some PB blaster into it and then use a block of wood to beat it back softly. After severals turns of this, the valve seem to work fine. I then took off the valve covers and found some water inside on of them and the other looks ok. I then took off the intake and had another bolt break on me. Great, I guess I have to drill that out all. got that done and then saw the real reason why the previous onwer junked the engine.

1: The starter stopped working as the wire came disconnect within the unit. This didn't let any current get into the starter from the battery.

2: The top cylinder stopped firing as it had a stuck valve.

3: The top cylinder burned lots of oil, which must have made it get so carbonized in the first place.

4: The lower cylinder also started to burn lots of oil and also had a carbon buildup issue.

5. The owner must have junked the engine and it sat for a long time, as some rust was starting to form on the top cylinder from water that would flow into the carb and down and out of the intake port and into the cylinder.

So, I then decided to do a complete tear down as it really needed it badly, so I took out the pistons and rods. I also will be taking out the valves and giving them a complete cleaning. I will be using the same pistons as they seem perfectly fine once i gave the wire brush to them. I also took the old rings out and again found so rusty areas. So, I clean it all up and it looks fine now.

I was then able to hone the cylinders out and cleaned them up very nicely. No more rust left (Mabye a few little specs) and they seem fine. I also looked at the crank and it looked fine. The same with the rods and such. Everything is super tight.

So I just ordered a complete gasket set and two new set of rings. When they come in, I will keep working on this engine.

Overall, it needs some TLC but I think I can handle it and hopefully it will give my lots of trouble free hours in the future. I'm also hoping it will have tons of power for my newly rebuilt 36in snowblower. :)