854 Engine Swap

[Racinbob 11,082]

There must be some engine swap fever going around. The original K-181 on my 854 is showing signs of it's age so it's time to do something.

 

 

I have had a K-161 for several years and haven't even started it yet but I'm told that it had an easy like running a pump at the mouse in it's early years. The 161 is a rope start with a mag ignition. Of course the 854 has a starter/gen battery ignition. My plans have been to swap out the required parts to convert the 161 to battery and so far it's been good to go. The first critical thing was a flywheel swap. I didn't know if it would be a direct fit. I did know that the engine pulley for the starter wouldn't bolt to the original 161 flywheel. I knew the 161 flywheel would pop right off since I had it apart a couple years ago and used anti seize on it. To my amazement the 181 flywheel came off without a struggle. They are fully interchangeable. 

 

 

This is looking like a super simple swap now. 

 

I've already swapped the choke shaft on the 161 so the cable can come from under it. 

 

 

1) Remove magneto from the 161. 

2) Change the two rear head bolts to the type with a stud so the starter/gen bracket can be mounted. 

3) Redo the oil drain. The bulky setup on it now won't clear the battery holder. 

4) Decide what I want to do with the fuel pump. I've got a new aftermarket mechanical, also a remote pulse pump or I could retain the electric on the 854 that I put on it a couple years ago. 

5) My plan is to use the coil and condenser that is on the 181. One thing bugging me is I recently saw a condenser somewhere that specifically stated it was for a magneto system. There is one on the 161 and it really doesn't matter because I'll swap it out but I'm curious if there's a difference. ????

 

Anything else you guys can think of? 

Here's the K-181 still on the 854

 

 

Edited September 4, 2023 by Racinbob

[Racinbob 11,082]

Something else just hit me as I was proof reading this. I'm going to swap out the tall dip stick on the 161 for the screw in type on the 181. I would prefer the pull out stick but it won't allow me to check it with the hood on. 

[ri702bill 8,326]

Bob - you are basically building a 754. Down the road, I too will be putting a K161S from a 702 on my 854 while I do a freshen up on the original 8HP.

The K161T came from a pump?? Be SURE your governor mechanism is functional - I Had a 5HP Tecumseh from a chipper I was going to use on a 502 - NO governor.

What you have looks like it grew there....

[JoeM 7,874]

What else is amazing is those old mag coils are still available. 

That is nice little project.

Fills good when things work out. 

[peter lena 8,631]

@Racinbob  hiding in plain sight ,4 TH  picture down ?  good opportunity for  a  vertical fuel check valve , in vertical run just before carb . holds / insures fuel is always there for easy starts.  just a suggestion , have one on all of my small engines , stops fuel drain back https://www.amazon.com/EVIL-ENERGY-Return-Petrol-Aluminium/dp/B085G7JVSM?th=1,  nice job, pete 

[953 nut 55,258]

1 hour ago, Racinbob said:

My plan is to use the coil and condenser that is on the 181. One thing bugging me is I recently saw a condenser somewhere that specifically stated it was for a magneto system. There is one on the 161 and it really doesn't matter because I'll swap it out but I'm curious if there's a difference. ????

Yes

he Kohler 230722 Condenser fits all battery ignition single cylinder and twin cylinder from the K-90 to the K-582.  The 235786 condensers are for the magneto equipped Kohler engines only K-161 to K-301

The unit of measure for a condenser is the Farad. Many electronic components like radios and TVs use capacitors that are in the microfarad range (ten to the minus six power Farads) and our small engines use a condenser that is in the nanofarad range (ten to the minus ninth power Farads) which is based on the voltage range they work in. A magneto ignition system uses a 100 to 250 nF condenser and a battery ignition system uses a 200 to 500 nF condenser. A good multi-meter will have a capacitor testing function.

Armed with this information you can walk into your auto parts store and get a very confused look on the face of the person on the other side of the counter. The capacitance is not listed on the package and probably not in any of the on-line data they have for the condensers they stock. You just have to go by the application chart and be sure that the condenser you are buying is for the type ignition system your engine has, not just the horsepower or engine size.

[Racinbob 11,082]

1 hour ago, ri702bill said:

Bob - you are basically building a 754. Down the road, I too will be putting a K161S from a 702 on my 854 while I do a freshen up on the original 8HP.

The K161T came from a pump?? Be SURE your governor mechanism is functional - I Had a 5HP Tecumseh from a chipper I was going to use on a 502 - NO governor.

What you have looks like it grew there....

 

I did think about the 754 thing. I guess it will make a good companion to my 'B'-160

It didn't come with a fuel pump. The tank was mounted on top of the engine. 

The governor seems to be fine. 

 

47 minutes ago, 953 nut said:

Yes

he Kohler 230722 Condenser fits all battery ignition single cylinder and twin cylinder from the K-90 to the K-582.  The 235786 condensers are for the magneto equipped Kohler engines only K-161 to K-301

The unit of measure for a condenser is the Farad. Many electronic components like radios and TVs use capacitors that are in the microfarad range (ten to the minus six power Farads) and our small engines use a condenser that is in the nanofarad range (ten to the minus ninth power Farads) which is based on the voltage range they work in. A magneto ignition system uses a 100 to 250 nF condenser and a battery ignition system uses a 200 to 500 nF condenser. A good multi-meter will have a capacitor testing function.

Armed with this information you can walk into your auto parts store and get a very confused look on the face of the person on the other side of the counter. The capacitance is not listed on the package and probably not in any of the on-line data they have for the condensers they stock. You just have to go by the application chart and be sure that the condenser you are buying is for the type ignition system your engine has, not just the horsepower or engine size.

 

Thanks Richard. After seeing that one specifying that it was for a mag system I wondered. I never knew there was a difference. I'll just use the condenser that's on the K-181. I'll also test both of them. 

 

[Lane Ranger 10,968]

I had a k161 I bought from

another Red Square member about a dozen years ago.  I had it sitting in the Garage for about 7 or 8 years.  Magneto type and pretty original from an old Wheel Horse.   Finally used it on a 603 I bought from the late John Campbell in Toledo.  He had a great 603 tractor without a motor.  My motor was perfect for the 603 even though the original tractor had a Tecumseh on it.  Of course my K161 was magneto/recoil start not an s/g type. 

 

Bob, the K161 should work fine for power on your 854.   Lots of tractors have K181s on tractors that were originally 6 or 7 hp powered.

 

I am not a very good motor man but I think you should be able to covert the K161 block to a K181 with the steps you are taking.  That condenser issue detailed by Richard is something I have run into on these early motors used in Wheel Horse tractors .  You definitely need to match the condenser to the other parts used in the motor you select. 

[squonk 41,121]

If you end up rebuilding that 181, I would swap out the cam and tappets for a compression release one. 

[Racinbob 11,082]

@Lane RangerThis tractor is mainly used with the sickle mower and, on occasion, to pull a water tank. Both low HP jobs. I'm glad Richard educated me on the condensers. I likely would have just left the one on the 

K-161 and wondered why something wasn't right. 

 

5 minutes ago, squonk said:

If you end up rebuilding that 181, I would swap out the cam and tappets for a compression release one. 

 

I won't be rebuilding it Mike. I'm not much into small engines. It runs OK but has a funny noise. I'm thinking maybe a burnt valve. I'll just get it to somebody that wants to save it. 

 

[Pullstart 62,902]

For consideration, my K181 powered 502…

 

It has no fuel pump.  The tank is higher than the carb.  Gravity has been holding true for quite some time.  
 

 

 

 

Originally I ran the fuel line out and about but it was not clean.

 

 

I clearanced the fan shroud and built a little tube and bracket to run a fuel hose through.

 

 

 

Cleaned up, it looks pretty nice if you ask me…

 

[WHX?? 48,821]

Check the flywheel bores for cracks at the keyway Bob.  I had a couple. 

[Racinbob 11,082]

3 hours ago, Pullstart said:

For consideration, my K181 powered 502…

 

It has no fuel pump.  The tank is higher than the carb.  Gravity has been holding true for quite some time.  
 

 

 

 

Originally I ran the fuel line out and about but it was not clean.

 

 

I clearanced the fan shroud and built a little tube and bracket to run a fuel hose through.

 

 

 

Cleaned up, it looks pretty nice if you ask me…

 

I think I'll try that first Kevin. I can always add a pump later.

[Racinbob 11,082]

48 minutes ago, WHX?? said:

Check the flywheel bores for cracks at the keyway Bob.  I had a couple. 

I didn't do that and wouldn't have. I will now. 

[WHX?? 48,821]

It was odd Bob ... a 161 & a 181. Couple a door stops now. 

[squonk 41,121]

Impact guns cause that or not torqued enough.

[Pullstart 62,902]

1 hour ago, Racinbob said:

I think I'll try that first Kevin. I can always add a pump later.

That was my thoughts 5 years ago as well.  Generally I can start it on the first pull!

[WHX?? 48,821]

34 minutes ago, Pullstart said:

That was my thoughts 5 years ago as well.  Generally I can start it on the first pull!

I don't doubt that Kev them points are set in the sweet spot. 

 

1 hour ago, squonk said:

Impact guns cause that or not torqued enough.

PO thing Sqounky we'll never know...I'm quite sure Bob is gonna follow the manual.

[Racinbob 11,082]

2 hours ago, WHX?? said:

It was odd Bob ... a 161 & a 181. Couple a door stops now. 

Upon further inspection it looks like I'll have to find something else for door stops. 

 

1 hour ago, Pullstart said:

That was my thoughts 5 years ago as well.  Generally I can start it on the first pull!

My only reason to hesitate on gravity is that the 181 got fuel starved at a 1/4 tank. No harm trying again with a different engine.......if that could matter. 

 

 

[Pullstart 62,902]

Mine only gets starved when the bottom of the tank is dry 

[Racinbob 11,082]

More education for me. 

 

I pulled the 181 off the 854 this morning. There was some crud on the frame but not as bad as I figured. 

 

 

I saw this stuff advertised and being a Dawn product I wanted to try it so I picked up a bottle 'for my wife'  to try. I snuck it out of the cabinet and sprayed the frame front. Waited a couple minutes and hosed it off. The stuff worked great and it's much user friendly that most of the degreasers I've used. I used it on the wheels too. I'll be getting a bottle for my cabinet. 

 

 

Going through my parts stash I found two brand new condensers. With @953 nut having educated me on the importance of getting the correct one for the ignition type I wanted to see what these were. I knew the one with the pigtail was a 230722 for a battery system like Richard mentioned. The one with the stud didn't have a number but was just like the one on the 161 for the mag system. Sure enough, both were right in the parameters. 

 

 

Another thing I learned. Fuel filters. I had switched the K-181 to gravity feed when the original fuel pump died and I couldn't figure why the engine started to starve for fuel at about 1/4th tank. I had a 75 micron fuel filter on it. Filters that fine are for engines with pumps. Most of them state that. I needed to go with a 150 micron but an electric pump solved the issue. Supposedly a 150 is fine for a carbureted engine as particles that size will pass through. The finer filters are important for fuel injectors. My guess is that the fuel delivery was fine until the fuel level dropped down and the 'pressure' couldn't squeeze it through the 75 micron filter. 

 

 

[squonk 41,121]

I've been using the Dawn spray for about a year. Works awesome.

[ineedanother 1,369]

7 hours ago, Racinbob said:

 

 

Daggon. I just had to stop and look at how filthy my bench is 

[Racinbob 11,082]

1 hour ago, ineedanother said:

Daggon. I just had to stop and look at how filthy my bench is 

It's not always as it seems. That's a workbench I wasn't even done building yet. 

[Racinbob 11,082]

Guys, I need some guidance here. I was wrapping things up and putting the starter/generator belt back on. It's clearly old but I decided to use it since it won't be a TSC item. I may have been a bit aggressive with it and ended up breaking it. I went to the parts list and it doesn't give a p/n. I'm pretty sure it's a Gates 7312. It measures 31 5/16". With the gen adjusted as far in as it goes when I pull the belt tight around it I can get the ends no closer than 1/2" apart. The width is 3/8". 

So, I go to the Gates site. Per their chart a 7312 is 31.84". A 7315 is 32.34" which seems just right to me. What have you guys done?