OutdoorKing Repair Forum Forums Collectors Corner Cylinder Scott Bonnar 45 & Diplomat 430

Hi Guys,

After reviewing this great site for the past few weeks, I have have caught the restoration bug. I have picked up the below two machines in the past few days and was wounding if you guys can have a look over the photos to give me some advice on the current condition and if they look original (parts, colouors, decals, etc). I have done some research/reading already and know the year of the motors.

I initially only wanted the 45 but the Diplomat came with, See that the diplomat model are not very popular? Can any parts off the Diplomat be used on the 45? I plan on trying to get the 45 up and running as is, then attempt a restoration. I really have had no experience in any mechanical works previously but guess there is really only one way to start, jump in head first.


INFORMATION:
45
Machine: 45 21182
Motor: 80102 0233-01 76040901

Diplomat
Machine: 430 1851
Motor: 80202 0880-01 80062001

I haven't tried to start the 45 yet but itching to get started.

Any advice, information or comments would be greatly appreciated.

Thanks Ryan

45 Photos

G'day Widdo18,
I've shifted these images to a new post here, so that they'll display.





Diplomat Photos

Hi Ryan,

Well firstly welcome to the ODK Forums. As you've already noticed there is plenty of info here on this site that will keep you going til the end of time.

An interesting pair of mowers you have there. Firstly the Diplomat seems quite original and if it still drives then you've got a special one as most of them have had the drive gear fail in them and they haven't been available for many years. The best thing on it is the 3 HP Briggs engine. Personally I'm not a fan of this model at all even though it did win some design awards back in its day.

Now the Model 45 you have there seems to be a bit of a bitsa, firstly the engine is not its original unit as by the time that frame was made SB were fitting 3 HP engines on all 17 inch models. The early 1976 built 2.5 HP unit is from an earlier machine. The lower section of the handle bar is not the matching unit to the top section, also it's been painted black, something SB never did. I would date the chassis itself at around 1980 ~81 due to the sticker depicting the model and serial number which was done when Rover took over Scott Bonnar in 1980 also the colour of it was a short production run colour while Apple Green wasn't available. As proof of age note how the ID sticker on the Diplomat is the same white plastic as the model 45 and the engine on the diplomat is a June 1980 engine which means the mower was probably built around 3 to 4 months after that date. This correlates what I've suggested about the build date of the Model 45.

The bed knife has seen better days and will be due for retirement when the reel is next sharpened.

Let us know once you've got the engine going and how it performs.

Cheers,
BB.

A warm welcome to the ODK Forums, Widdo18.

To start with some basics, the manufacture dates of your engines are 9 April 1976 for the 45, and 20 June 1980 for the 430.
So they both have points ignition, and the correct Briggs repair manual for them is P/No CE8069. Illustrated parts lists and owner manuals are free downloads from http://bsintek.basco.com/MDEXResultsPages/default.aspx

That air cleaner element on the 45 isn't correctly installed - the outer lip of the foam is meant to extend over the top edge of the lower housing, to provide sealing. As shown here:


The Diplomat models are less than popular for a couple of reasons. One is that they are more awkward to work on than the 45's. But the major one is that they used a very failure-prone drive component from the factory - a nylon driven ring gear in the landroll. Some of these have been replaced by an aluminium gear that SB offered as a replacement, and if you're very lucky that machine will have one fitted.

Unfortunately, the upgraded part is no longer available now and hasn't been for quite some time..

Thanks Gadge & BB for the help & information, it is very appreciated. Im a little bit disappointed that the 45 doesn't have the original motor.

I will have a play with both over the weekend and report back.

Thanks Ryan

Hi Ryan & Mod Gadge,

Yes Ryan I can understand your disappointment in regards to the situation of the Model 45. I guess it would've been better if the situation were to be reversed, that way you wouldn't feel so bad if you were to strip down the diplomat, but truthfully even diplomats in that gooder condition are getting hard to find, not that anyone's really looking for them.

It will be interesting to see if the diplomat drives or not. If it doesn't then I'd take the engine from it and transplant it to the model 45 as it should have a 3 HP engine on it, not that there's that much difference between the 2.5 and 3 HP.

BTW Scott Bonnar did fit 2 HP and 2.5 HP units to the 17 inch model 45 over the years, actually around 1976 many 2.5 HP engines were fitted to the 45's. I guess that SB got a cheap deal from Briggs for purchasing a huge job lot of them in one go.

Anyway it will be interesting to hear back from you with the results of both machines.

Cheers,
BB.

Hi Guys,

I had a play with the Bitsa (the 45) yesterday and got it running!!! I drained the oil and old fuel and re topped up. It started straight away but then died. The carby was rattling very loose from the main body.

Upon inspection the thread in the body for one of the two bolts that hold the carby in place had been stuffed. I installed a hellicoil to the damaged one, replaced the two bolts (changed to a socket type) with spring washes and it seemed to hold and work good.

We cut a bit of lawn with the existing blades and it all seemed to work good.

Action Shot


I also noticed that there seems to be missing a bolt on the clutch?


Tried to start the Diplomat but no luck. Took the spark plug out but couldn't see it sparking. Will start to play with this one over the xmas break, im sure there are some posts the will help me investigate.

Can you guys let me know where I should be looking for the faulty part on the Diplomat?

Thanks Again

Hi Ryan,

Well the 45 seems to be a goer, but I will say with some urgency that the missing cotter bolt is of serious concern as the clutch body will not be held tightly on the output shaft and in no time it will flog the clutch body out and induce stress fractures into the engine mounting rails, something you should also check for before you go too much further. Clean all around the engine mounting area thoroughly and look for fine fracture lines in the green paint around the engine mounting bolt area on all 4 points.

Now my next question would be how did that cotter bolt come out as the only way for it to separate from the machine is to physically slide the clutch body off the shaft and only then will there be enough lateral clearance for the cotter to be able to slide out of the hole as it normally acts as a wedge against the output shaft as you tighten up the nut.

Can you tell me if the clutch rotates completely concentric or is there a bit of wobble in it as it revolves ? To test this you should be able to just pull the rope starter with the clutch disengaged and if it wobbles every so slightly then it's time for a new clutch half (Engine Side). If not then I'd organise a new cotter bolt and remove the clutch body and insert the new cotter then reassemble the clutch onto the shaft and away you go.

If there's no issue with the engine then I'd just stay with it as the earlier 45's were issued with a 2.5 HP engine.

As far as the 3 HP engine is concerned, if you are totally satisfied that there is no spark at all there will be three main points to address. Firstly the HT Lead and connection, secondly remove the flywheel and check out the points behind it to see if they are free and opening and closing, lastly the coil. Normally it won't be the coil, but it's all part of the process I guess.

BTW Have you tried tipping a small bit of fuel straight down the throat of the carby with the air cleaner removed ?

Cheers,
BB.

Hi BB,

Looked through the initial photos and cotter bolt was never there, i just didn't notice (newbie here).

So i have taken off the engine and have found a small section of crack in the rear rail.



Back Rail looks ok.


Can you point me in the direction of the best repair method? I have a welder buddy that should be able to look after for me.

Below are a few photos of the clutch & engine shaft. The shaft key way on the engine shaft looks a little worn porobably due to the cotter pin not being installed.

Also The two halves of the clutch have a little play/movement when put back on the shafts. Not sure if this is a problem as not sure how much is acceptable? The pin for the engine is also missing a bit at the end.








Thanks Again

Hi Ryan,

I'll have to say you've caught it early and thus it's easily repairable by a competent welder that won't need to spend hours on it.

As it's just a small section all you'll need to do is grind out a small channel along the fracture and then carefully weld it up. Honestly a welding tradesman will know exactly what he needs to do with a Mig welder and not induce twist into the chassis. Ensure that the roller and Bed knife are still installed while the repairs are being done. This will hold the frame rather rigid.

The key steel you have there will just require rubbing the high ridges off of it on a flat piece of emery paper.

Now here comes the sad part, purchasing the new clutch half that will set you back around $80 odd $$$$. The new style will have two pinning set screws that will pin the clutch body to the PTO shaft at right angles and thus it never should come loose like the old cotter pin clutches do. BTW it's the old clutch that's induced the fractures into the engine rail by running unbalanced.

I would also use a strip of emery and run it up and down the PTO shaft taking particular attention to the flared out key area as the edges will wear hnto high spots making it hard to install the new clutch body.

I'd say your clutch cork is still ok as it has plenty of thickness after you clean out the gunk around the edge of the cork.

Now I guess I should ask the obvious question, what are your long term intentions for the Model 45 ?

Cheers,
BB.

Thanks BB.

A question, do i need the new clutch half cause the screw is missing, or is something wrong that you seen on the photos? i dont mind spending the money on the new clutch, just wanted to check.

My intention is to continue with the repairs and keep for my own use at home. As I dont really know much about them this would be good practice for any future restores i attempt.

Would a new Briggs motor cut down on vibrations compared to the old motor?

Thanks Ryan

Hi Ryan,

From my experience that clutch will be scrap alloy and nothing better. It's age is against it and how long the cotter was loose and then pulled apart and discarded as they don't just fall out, along with the tell tale signs in the rail tells me that you will have no other choice but to replace it. Also you told me that when you removed it there was a bit of free play in it on the shaft is enough not to consider it any longer as there should be basically none, a clean slide on fit only.

The particular version of the clutch you have there would have to have been the most troublesome for Scott Bonnar, but it certainly kept the cash registers ringing over and over again.

I've inspected the close up photos of the drive train behind the chain case and all seems rather in order there so there's not going to be a hellva lot of cash that's required to spend on it apart from a spin grind of the reel along with new bearings on each end and a new bed knife fitted.

Cheers,
BB.

PS. Yes the new style sloper engine from Briggs are most definitely a smoother running engine, along with the Honda's and Chonda's.

Thanks BB.

Will get the new clutch, bearings, fix welds and a sharpen and see how it goes. Thanks for the advice, glad i didn't continue using and make it harder to fix.

Thanks Again

Hi Guys,

An update and a few questions.

The 45:
I've had the cracks in the frame welded up and part of the way putting it apart for restore. Still waiting on some parts to arrive (clutch, seals) that were ordered during Christmas.

Thinking of getting the reel and bed knife sharped while Im waiting. Im looking for information/help to prep and paint the reel. I seen some post talk about powder coating. Can I just paint it by hand with out powder coating? Any tips on prepping the reel for paint and the type of paint to use?

The 430:
I want to remove the reel and bed knife so i can get sharpened at the same time as the 45. Im not sure about how the remove the drive belt and remove the reel? Photo below, any advice/tips?



Thanks Again!

Ryan

Hi Ryan,

As far as the reel prep is concerned I'd get it bead blasted and then spray paint it using a good etch primer prior to the colour coat afterwards.

"DO NOT" Powder Coat the reel or any part of the mower. This topic of discussion has come up time and time again. As you would be doing the colour prior to reel grinding this makes powder coating unsuitable as you would be breaking the powder coating sealed finish thus allowing moisture to penetrate under the remaining coating which creates a rust issue underneath. Powder Coating is merely a cheaper production option for manufacturers opposed to painting and really isn't suitable for an item that will suffer surface abrasions and sealed surface compromises. If you look at a lot of the Kermit Green Rovers that were made at the Eagle Farm plant in Brisbane you'll see that the surface is all blistered and eventually the green coating will come off in sheets revealing a totally rusted steel surface.

I suggest as far as blasting is concerned that it would be best to put all the parts for blasting together and get them done as a single job lot, it's simply cheaper that way opposed to taking parts in as separate job lots which will only end up costing you much more in the long term.

Cheers,
BB.