OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Reel-Type Mowers MODEL 45 - 17 & 20 rebuilds

Hi All,
Been looking for a 20" model 45 since the last reno and was lucky enough to pick one up last winter. Condition was fairly poor and without and engine but reel and sprockets appeared to have a bit of life left in them. My son also had another 17" so we have decided to restore them side by side with a view to them both being used regularly. Have posted a couple of pics of the 20" for comment.

Hi Mr Jones, Unfortunately we did not get a chance, from the pics, to asses the sprockets and chains..... but even without pics, I can give you this advice....If ANY of the sprockets have really pointy teeth, it is time to replace the sprocket and the chain that drives it.

the front rail is substantially cracked, in fact its in two pieces!

Certainly looks that way from my eyes as well!

Thanks Deejay,
Will add a picture of sprockets when mower is re-assembled hopefully soon. Thanks to those who noticed the small crack in the rail. Have attached attached a pic of the fix. Would also like any ideas on a ball bearing front roller for the mowers. This is the one thing that lets down the mowers a little. Have looked at installing a conveyor roller? Would appreciate any suggestions as I think I have seen at least one on the site before.

Hi Mr Jones,

Can you please take some more close up photos of all around the repaired rail area ?

Cheers,
BB

As parts are back from paint here is a better picture of the repair. A little overlap on inside edges but wont be seen from height and with engine installed.

Hi Mr Jones,

The more I look at that gusset welding job the more I like that idea. It's most unintrusive.

I have to ask, what formulation did you use for the colour or was it custom mixed at a crash shop ? As it looks pretty much spot on for the mid to late 1970's mowers.

Cheers,
BB

Did you weld the cracks in the rails as well as fitting the gusset plate, or just fill them with bog?

The way the gusset itself has been attached seems to give good prospects of avoiding heat distortion of the frame. How did you restrain the frame while welding, and/or gauge the frame for straightness after the repair?

The process was to first straighten the rail as best as possible with a press done very carefully. Next the gusset was tacked into place to secure the shape. This was then followed by grinding out the crack and carefully welding them up. The gusset was then fully welded in place and some light grinding for a decent finish. Hammered paint takes care of the rest. Have to say happy with the result but haven't put an engine on it yet. The paint has been a bit of a nightmare. Its a Protec 311 hammertone mixed to a sample taken from under the handle grip of a model 38 edger. Its close but the first coat had a few runs and had to be sanded back and repainted. It also took about a week to be anywhere near hard so you could handle any parts. Wont be using it again as its too thin in the can.

Hi Mr Jones and Grumpy,

Well I'd say that you'll never have any issues with those rails again as that's probably been the best remedy that I've seen done and as you said you'll never really see it unless you're a roller.

Did you by any chance get the formula that was used to make up the colour ?

Cheers,
BB

i just love how a sandblast and paint brings these objects back to new from such very old tired worn states.

Will respond on paint but need to visit the supplier for code. Will follow up. Have posted a bit of progress so far. Jnr is a bit ahead on his 17" but we need to tackle the front roller problem. As shaft is 5/8" could use a cutter bearing and machine some end caps to use with original size roller tube. This would let us revert to plastic end caps if required. Would prefer to have front rollers with bearings. Have also been able to source a 6.5hp Vanguard engine brand new at a very reasonable cost but I am a little concerned that it will be too much for the 20" mower frame. Should run at a little over tick over though! Thoughts on roller and engine appreciated.

Generally, the greatest demand on the drive train of a reel mower, is when mowing up a steep slope or powering it up a ramp onto a trailer or terrace. I agree that if you only limit your ambitions for climbing ramps and kerbs to whatever stalls the engine, the 6.5 hp engine could be a problem.

In normal mowing the engine weight and the rotating inertia are important, but within reason, extra power in itself should do no harm. The drivetrain can only be harmed by too much engine power if the mower meets resistance and therefore the drivetrain has to transmit all of that power. If you pick up a bolt between reel and bedknife for example, the engine will be stalled immediately, more or less regardless of its power, since the governor will not even have time to open the throttle before all rotation ceases. The factor which will cause damage in that situation is the momentum of the rotating parts. Hence in routinely mowing flat lawn, the main thing to avoid is an engine with a cast iron flywheel, rather than one with a moderate amount of excess power.

Hi Guy's,

These two machines are looking better and better every time I see them, especially with that fabulous colour which makes these machines so striking in appearance.

Is that a brass height adjuster or a painted die cast version ?

Really looking forward to the formula of the paint.

BTW I'm wondering if making those gussets a bit longer would be a strength advantage or would it just place more stress on the weld joints securing the rails to the side plates ?

Cheers,
BB

in regards to power, even the 1979 model original 3HP on my 17" seems excessive. going up the rise on my front lawn it has no hesitation and on the flatter back lawn i use the clutch to get it moving but then its momentum keeps it rolling just fine. thats all on half throttle too.

BB, fwiw suggesting a change in the gussets at this point of his build(post weld, post paint, post assembly) only puts more doubt into the repairers mind as to the best guess anyone has ever taken so far to repair a twin rail SB. Only time will tell.........

My thoughts are the same on the engine. An original 3hp 80202 with auto choke is high on my shopping list for restoration and this would be plenty of power for a 20" on flat ground. I may initially fit my 3hp 90112 for the purpose of a test drive but hard to turn down the 6.5hp for the price. Jnr,s adjuster is a brass item and would assume came from an earlier solid deck.

Hi Mikeo,

I'm not for one moment suggesting for Mr Jones to jump ship at this point, it was merely an observation for any future repairers to consider as this problem would be encountered by around 8 out of 10 17 inch machine owners and 10 out of 10 for the 20 inch units.

This topic has come up so many times on this forum that every improvement can only be a step in the right direction.

Cheers,
BB

the materials in these machines have a design life thats for sure. if only Sid had some FEA.

I have a spare 80202 that i intend on cleaning up and returning to new having run the other 80202 on the 17" for a couple of weeks now, they are impressive engines!

I don't think you can blame Sid Bowditch for the design weaknesses of the twin rail machine, I believe he only designed the single deck version, which was quite good from the fatigue life point of view. To critique that design we'd need some pictures of cracked single decks.

The source of the problem with the twin rail design may have been vertical resonant vibration of the engine and rails as a mass-and-spring system. That is not a mistake Sid seems likely to have made, particularly if the rail resonance was the source of the excessive vibration so many twin-rail SB45 owners complain about. There must have been a reason for the complex construction of the single decks, and overcoming a resonance problem observed during product development may have been that reason. Of course if cracks developed the vibration would have increased in amplitude.