PDA

View Full Version : Kohler to Briggs conversion?


mistermopar
06-04-2011, 06:05 PM
The motor on my Scag walk behind (cv 20s kohler) let go of a wrist pin today I think. I have a 20hp Briggs off of a residentail mower. I know this isn't a long term fix, but I am desperate. I dont mind adapting two different wiring harnesses as long as they are compatable with each other (my kohler harness to a briggs motor) . Whats most important is if the shaft size is the same and the mounting will work without modifying the mower. I really apprecialtte any input, I'm even ready for a little bashing, I know this isn't the smartest thing to do. Thanks Chris

Patriot Services
06-04-2011, 06:14 PM
I'm assuming this is a belt WB. Easiest way is go ahead and pull it apart. The shaft size and length are what's important. Even then you can still get a pulley that would let you get things lined up. Everything else is gravy. Mounting holes will prob line up if not drill new ones its just sheet metal. Throttle cables are pretty universal too. Graingers, northern and harbor freight are good sources for pulleys and cables on a Sunday.
Posted via Mobile Device

mistermopar
06-04-2011, 07:42 PM
Okay I'm tearing it down now but I want to figure out the wiring first. The mower with the briggs has a connector with three wires a blue,Orange and black. The Scag's harness has three wires as well but they are green white and yellow. Can any light be shed on what each wire does on the two different harnesses. Thanks Chris.
Posted via Mobile Device

Snapper Jack
06-04-2011, 07:44 PM
The motor on my Scag walk behind (cv 20s kohler) let go of a wrist pin today I think. I have a 20hp Briggs off of a residentail mower. I know this isn't a long term fix, but I am desperate. I dont mind adapting two different wiring harnesses as long as they are compatable with each other (my kohler harness to a briggs motor) . Whats most important is if the shaft size is the same and the mounting will work without modifying the mower. I really apprecialtte any input, I'm even ready for a little bashing, I know this isn't the smartest thing to do. Thanks Chris

Did you tear down the Kohler to see what damaged occurred? I believe they share the same bolt pattern,problem with Kolkers is they have so many different crankshaft lengths. They are wired different that's for sure. Good luck to you in getting your mower up and running again.

Patriot Services
06-04-2011, 07:56 PM
You should be able to find the B&S schematic on their site and match to what's connected to the kohler.
Posted via Mobile Device

mistermopar
06-05-2011, 11:45 AM
Motor is on and running all is functional. I had to change the wiring up a bit, I didnt cut the factory kohler harness. I will be putting another kohler back on it sometime in the future. I modified the kohler exhaust to fit the briggs, its wild how close they were I just had to widen the two into one manifold about a inch. The Briggs is alot quieter and smoother, I think it will serve okay until I can get a replacement for it.

Patriot Services
06-05-2011, 11:54 AM
Nice job. Saved yourself a bunch of money. Its usually not a big deal as manufacturers offer different engine options all the time.
Posted via Mobile Device

Snapper Jack
06-05-2011, 01:38 PM
That was quickThumbs Up

mistermopar
06-05-2011, 03:59 PM
It isn't mowing like it did, I think its not turning the rpms the kohler did. It's leaving grass uncut and a strip of clippings. Any thoughts. Thanks Chris
Posted via Mobile Device

Patriot Services
06-05-2011, 04:08 PM
Throttle opening all the way? Same size engine pulley?
Posted via Mobile Device

Snapper Jack
06-05-2011, 04:33 PM
The engine drive pulleys need to be same diameter and the groove in the pulleys need to be the same width also. If there's any slack in the throttle cable where it attaches to the carb bracket,it will limited engine RPM at full throttle.Give it full throttle,loosen the screw at the bracket and pull till choke kicks in, then slightly back off till the RPMs reach maximum potential without sputtering and tighten the screw down.

mistermopar
06-05-2011, 05:08 PM
Same clutch pulley set up, the governor is keeping the rpms from increasing. I see no kind of adjustment or alternate spring holes. The throttle is opening all the way when not running though. So I assume it is at the preset max rpm.
Posted via Mobile Device

Patriot Services
06-06-2011, 10:05 AM
Governors usually do have an adjustment. Loosening the arm and moving the arm will raise or lower max governed rpm.
Posted via Mobile Device

mistermopar
06-06-2011, 10:42 AM
Thanks folks, I'm on here most everyday absorbing a lot of useful info. I will get to the point to where I am answering instead of only asking questions. Oh I will try adjusting the governor ARM. I wish I could monitor the rpms somehow. I have the ear to tell when I think something is being over worked or not efficient but I would still rather be able to see the actual rpm reading.
Posted via Mobile Device

snapper
06-06-2011, 11:40 AM
dont touch the governor arm!! all you will do is mess up the governor.. you have to put more tension on the main governor spring. some have a secondary spring for governed idle. to adjust the rpm some have a plate to move, some have a bolt type adjustment, some you bend the tang the spring hooks to.. but dont touch the actual governor arm or bolt..

Later!! chris

Patriot Services
06-06-2011, 11:58 AM
Go to the B&S website. Step by step instructions.

#1 loosen the adjusting arm bolt.
Posted via Mobile Device

snapper
06-06-2011, 07:06 PM
the only time you loosen the nut is to rest the arm to the shaft. you push the throttle wide open, turn the shaft the direction of wide open then tighten the nut. to increase the top governed rpm you must increase governor spring tension. there is no other way.. just dont want to see a some one tear up a good motor, because if you mess with the arm to shaft it will probably over speed and could damage some thing.

later!! chris