148cc 3.5HP/4.5ft lbs converted Briggs mower engine

For Sale:148cc 3.5HP/4.5ft.lbs. converted Briggs mower engine

I'm looking to sell my Briggs and Stratton engine. It started it's life out as a vertical shaft engine on a 2006 model year push mower. After reading around the forum to see if it was possible to convert this engine to run on it's side, I noticed that there wasn't really a definitive or well documented answer. So, I decided to give it a try on this motor to see if it could be done. BTW, yes it is possible!

The engine has all new gaskets and a new oil fill hole on the side. (and a red head just for fun ) I also had to cut new oil channels near the bearings and plug up some of the old ones as seen in the image below.



Also, I decided to go with a standard NT carburetor meant for 66/80cc 2-stroke engines so a twist throttle could be used. I did a few quick tests on the bench to make sure that the carburetor would work, which it does.

Anyways, now that the project is complete, I don't have much of a use for the engine. I'm open to offers as I haven't really decided on a price. The buyer will pay shipping, though. I'll make sure to drain the oil before shipping it to cut costs.

Shoot me an email at [email protected] if you're interested. Also feel free to post any questions or comments in the thread below.

Thanks,
pulsar2121


Here's a few photos with and without the cover on.







P.S. In case your wondering, the muffler is a screw in type, but there are mounting holes in the engine block near the exhaust port so a bolt-on style pipe can be used.

scotto- said:

Drop that thing in a drop loop frame and really look vintage with a rope pull starter. What direction is the PTO in that position? It would help if it's CW for right-hand drive.
It's a flathead, it's a redhead, it's a flat redhead

Click to expand...

I like the way you think. This would look pretty sick on a 50's or 60's era Schwinn. Racie35, is right though: the PTO does turn counterclockwise. So you'd have to mount the engine with the PTO on the right side, but hey it would take the jackshaft part out of the workings if you plan on paring it with a shifter kit.

Also, LOL on the "flat redhead." We better be careful or we might have ginger snap situation. https://www.youtube.com/watch?v=NKvHkcANLcg

Hey MT,

I did some research on the forum about the recoil and found some of your old posts that show the sheared off flywheel key. I don't think it applies to this situation though. This recoil just has two spring loaded arms that fit into the grooves in the cup that bolt onto the flywheel. The arms disengage when the engine starts. That being said, the recoil works just like it did when the engine was mounted vertically on the mower. So I don't really foresee any issues.

The only thing on the recoil that I modified was rope length so it didn't hang out. (Ropes are longer on vertical shaft engines so they can mount on the handlebar of the push mower.) I guess the top part of the recoil housing could be rotated so the rope pulls up instead of down, but that would just be for ergonomics really since it would still turn the flywheel clockwise and the PTO counterclockwise.

Well, I decided to give your recoil rotation idea a try. I drilled out the rivets and then used bolts to put it back together. Here's a picture of what it looks like now.



Wow, it was a lot of work to get that spring on the inside of the recoil back into place and working again. It wasn't worth the hand cramps in my opinion, but now it's correct at least.

I did see the video on youtube where the guy cuts off the round part of the engine side cover, but I didn't think it was really necessary. It's more of a "just for looks" thing.

Anyways, great find on the thread discussing the engine mounting plate. I'm sure my future buyer will appreciate it. Of course the engine could be mounted off to one side or rear mounted in a trike frame too.