OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers Diplomat 590, belt setup

Hi there, sorry for the poor quality of the photo but is my belt / clutch setup. It has the handlebar clutch setup which when at rest (deactivated) the drive and cutter drum is disengaged.

According the engine production (99% sure its original) date it is circa 1980 model.

Hi fritzymark, and a warm welcome to the forum. Its great to have another Scott Bonnar owner on board. We all like to learn new things and tinker here.
Thanks for posting the photo of your 590...its easy to see how yours works because of the Bowden cable and the tang welded to the chassis frame to support and adjust it....if you compare that with the pic on page one of the topic...the belt set up is the same except there is no tang on which to support the cable....its got me tossed how it can drive.
Once again, fritzymark,

It could work just as well if the crank pulled by the Bowden cable in fritzymark's machine is actually a bell crank in the original machine, with the operating lever on the opposite side of the side plate.

Hi Grumpy, that's just the thing....the Model 590 doesn't have a lever on the opposite side.....how does it engage the drive?

Deejay, I was wondering if it had the Bowden cable termination on the other side, rather than the long hand lever that the 430 has. In other words, a bell crank, but a short one.

not a comment or any help but i to have a diplomat thats model 430 a runner i was wondering do the chain drive models have a constant speed mine tends to bolt its hard to keep an average speed with the clutch lever is this due to riding the clutch or the belt heating up with the lever all the way out it tends to make me run behind not literally of course know what i mean a slight jog obviously it should have a steady walk not a run is this why there not that popular also the catcher has a tendancy to fall of the engine however a briggs 3 hp runs like a swiss clock even after yrs of dormancy it also says on the instruction manual its an edge trimmer any one used it as an edge trimmer it definately looks dangerous no covers maybe never happened the part no for the trimmer is434394

Hi impala, and a warm welcome to the forum. It's great to have another Scott Bonnar owner on board.
In order for us to answer correctly...we need you to post some pics of the machine from different angles and especially the troublesome areas...
Once again, impala, to the OutdoorKing forum.

A bit late to reply but I couldn't help myself, I just mowed my lawn today with my SB430 and it is hard to drive slow which is a proper pain in buttocks when your in a small area. A new belt and low rpm would be good I think. My belt slips making it slow to take off when the revs are up.
As for the catcher falling off there's a spring clip that seems a little weak and my catcher has fallen off a couple times because of it. A stronger spring should solve that.