Super easy conversion for vertical Briggs on zero turn
Posted: Thu Jun 27, 2019 10:31 pm
A rainy afternoon and I'm moving along with converting more of my equipment on the farm to propane. Next on the list was this pesky JD Z225 mower that has been a hard starter ever since I bought it and has a bad habit of draining the fuel into the crankcase. There are lots of expensive conversion kits out there for these but I got it done for under $50CAD using some modified commodity parts.
Images:
https://photos.app.goo.gl/V2ZvDK9x9GqpCRXh7
It's a "18HP" vertical 500cc Briggs that has been JD-ified by making some parts nonstandard. There is an identical motor in regular Briggs trim on the brushcutter beside it in the first photo, which might end up on propane if I can figure out where to mount the tank.
I have a Honda generator running this carburetor: https://www.amazon.ca/gp/product/B07PLMJ1Z6 which appeared to be very similar in form factor. It turns out to have the same bolt pattern and a similar throat size. It bolted up with the simple use of a pair of 3.5"x1/4" bolts and the gaskets supplied, and it even fits the original air horn and molded in air box! The only issue was that the throttle butterfly turned the opposite way in the generator, so I had to cut off the top stub and epoxy on my own small aluminum arm to mimic the original carb's control arm. Then I just strapped the negative pressure regulator to the side of the intake manifold. See images for details.
I would like to advance the timing a bit but I think I'll have to make a bracket to move the magneto, or pop off the flywheel and rotate it? Too much work for today. So it's running stock timing for now.
A little tweaking of the idle stop and mixture and this thing runs great out of the box and chews up tall wet grass without stumbling. The only issue appears to be under prolonged load it starts to freeze the BBQ regulator, causing occasional spontaneous stalling? It will restart immediately with no issues. The regulator shouldn't be freezing though, as I'm drawing vapour and the tank is not frosty... Maybe a high flow protection trip in the regulator in case the BBQ hose breaks? Not sure where to get a higher flow version of these guys.
Thought I would post this as these vertical Briggs motors are very common, as are these generator carbs, but I've never seen the two put together before.
Images:
https://photos.app.goo.gl/V2ZvDK9x9GqpCRXh7
It's a "18HP" vertical 500cc Briggs that has been JD-ified by making some parts nonstandard. There is an identical motor in regular Briggs trim on the brushcutter beside it in the first photo, which might end up on propane if I can figure out where to mount the tank.
I have a Honda generator running this carburetor: https://www.amazon.ca/gp/product/B07PLMJ1Z6 which appeared to be very similar in form factor. It turns out to have the same bolt pattern and a similar throat size. It bolted up with the simple use of a pair of 3.5"x1/4" bolts and the gaskets supplied, and it even fits the original air horn and molded in air box! The only issue was that the throttle butterfly turned the opposite way in the generator, so I had to cut off the top stub and epoxy on my own small aluminum arm to mimic the original carb's control arm. Then I just strapped the negative pressure regulator to the side of the intake manifold. See images for details.
I would like to advance the timing a bit but I think I'll have to make a bracket to move the magneto, or pop off the flywheel and rotate it? Too much work for today. So it's running stock timing for now.
A little tweaking of the idle stop and mixture and this thing runs great out of the box and chews up tall wet grass without stumbling. The only issue appears to be under prolonged load it starts to freeze the BBQ regulator, causing occasional spontaneous stalling? It will restart immediately with no issues. The regulator shouldn't be freezing though, as I'm drawing vapour and the tank is not frosty... Maybe a high flow protection trip in the regulator in case the BBQ hose breaks? Not sure where to get a higher flow version of these guys.
Thought I would post this as these vertical Briggs motors are very common, as are these generator carbs, but I've never seen the two put together before.