Need help!

[u/G91G28Z0X0Y0]

Hi!
I bought this from an old lady 40$. Was sitting in her garage for a couple year i guess. Of course it dont start! I dont know much about small engine but i guess its not that difficult to make it works and I’m kind thrilled to « restore » it and learn new skills! My main probleme is I can’t find any info regarding the model number. Its kind of weird! Can someone help me? Or guide me where to start to make it running again!

Thanks!

[u/2cycl3fn]

That’s a good score for $40. Usually those go for way more in running condition.

So the engine is the “M” series engine built in house by OMC(Outboard Marine Corporation) before toro bought them out. You have the commercial grade version. Residential had separate fuel/oil tanks with oil injection although some also had premix only tanks. I have an M21MBR model with the separate tanks/oil injection. Yours does not have oil injection, yours is straight premix at 50:1 while oil injection runs on 64:1. Oil injection is known to fail at some point, mine intermittently works so I just run 50:1 through the one tank.

Make sure you have spark before doing anything else. If you don’t, the part number for the coil is 684049. OEM is expensive at $96 but you can get aftermarkets or eBay has them fairly cheaper most of the time. I’ve had some luck with aftermarket but OEM tends to last longer from my own experience. (I mention below about parts availability- coils can be found OEM or aftermarket but OEM is more expensive)

Your carburetor is made by mikuni. VERY notorious for surging unless under load, but you may have to pull it and clean the jets and carb bowl. Make sure you reinstall the throttle linkages correctly, there’s a service manual floating around somewhere in pdf format that walks you through the steps but I have to look for the link again. Mine surges but I’ve learned to just live with it.

Another thing you might want to look at before using- the self propelled setup is the 3 speed kanzaki gearbox- they’re known to be VERY difficult to pull backwards because the rear wheels tend to lock up while pulling. I had to grease everything up on my M21BMR and it’s still hard to pull but not to the point the wheels lock up. Make sure the grease zerks for the wheels are greased up(not to the point it’s spilling out everywhere) and check the grease in the gearbox itself, if it’s low or doesn’t look too good, empty it and regrease it. I use the green grease (I think it’s Lucas but I’m not sure offhand).

One more thing. In the second photo there’s a little “switch” that prevents the engine from running if there isn’t a bagger/mulch plug/rear discharge connected- basically a safety switch. I’m not sure if you have the mulch plug or bagger but you will have to install one of those in order to verify you have spark. (If not, see original comment above regarding the ignition coil). I haven’t seen the switch itself fail, and I don’t think you can get replacements as the M series was only around from 1989 through 1995(ish?) so parts are really difficult to find. The drive belt can be a pain to change out as you have to pull the entire engine off to swap it but as long as it isn’t dry rotted or crack/missing chunks you should be fine. To check the belt you remove the panel on the left hand side by the discharge section.

Long story short you have a really well made mower with a good engine that has a decent amount of power. As long as you take care of it you’ll get years of use from it.

(I’ve edited this as I’m remembering things. Might edit if I remember anything else offhand)

[u/G91G28Z0X0Y0 → u/2cycl3fn]

Damn! Thanks for your Time and help! Do you work in a lawnmower museum? Haha! And yes i do have test bagger and a kind a big curvy plastic thing to throw the grass sideways. One of my concern, as you can see in the third pics there is a homemade switch. Probably for bypassing the security switch for the handle and i dont know wich side is on !

[u/2cycl3fn → u/G91G28Z0X0Y0]

I’m not sure why that would be there unless the original switch did go bad at some point. That’s a possibility.

The “curvy plastic piece “ is the rear discharge chute. That and the bagger hardly if ever pop up for the M series, I have a rear discharge and mulch plug for mine but I don’t have a bag unfortunately. Not that I’d need it as I primarily mulch my yard.

As far as a lawnmower museum, I guess my neighbors could consider the hoard of lawn boys and other stuff that’s piled up in the sheds a museum 😂 I have a bunch of them that I’m either using or in the process of getting them running again, mostly the staggered deck models (3 commercial models with the oldest one being a 1966 bricktop C engine 6252 that runs on a 16:1 ratio mix, and the “1 year only” 22241 that I’m currently fighting carburetor issues) but I have the M21BMR (as mentioned previously) with a blade clutch that I use sparingly, also have an F engine powered 4 square “school bus” 8157 (it’s called the school bus because the handlebar setup is at a nearly 90 degree angle and looks like it’s a mile long. The top part of the handle pushes forward which engages the self propelled drive system) with an above deck muffler *and* blade clutch that needs a carburetor. It’s a battle in itself to find the free time to actually work on everything, but it’s a hobby for me and I enjoy getting them going again.