Masport 550ST Series 19. How to tighten drive belt

[Chuzupop]

I cannot see any slot on the side.

These are the numbers I can find on the chassis:-

582062

Part number 579629

Series 19 550SP

Motor. 190

2850

Self Propelled 573298

If any of this helps.

 

[Chuzupop]

This is the right hand side from front

 

[bertsmobile1]

None of those numbers do me any good on the Masport dealers portal
So back to square 1
is it a single ( fixed speed ) or a variable speed transmission
Roughly how old is it ?

The adjusting slot is on the GEARBOX mount either under the mower or behind the left wheel.
Otherwise there is some adjustment on the cable which moves to box to tighten the belt.

 

[Chuzupop]

Hi it is fixed speed. I would say ten years maybe but was never used. I simply cannot find any means of adjusting the belt.

 

[bertsmobile1]

Take the spark plug out and stand the mower up on its front wheels so you can see the entire transmission.
There has to be something there to prevent the transmission rotating when you engage the drive otherwise the transmission will cant forward enough to throw the belt off .
According to what I can find it is either an anchor plate on the left side of the gearbox which has a slot in it to adjust the the position of the gearbox and thus the tension in the belt.
Another system is a stud that passes through the bearing retainer and sits in a slot
The third is the bearing retainers themselves being able to pivot on a mounting bolt.
To get at the last two you have to remove the left wheel because you can not see them while the backing plate is in position.
I have gone back through all of the available material from 2000 till now and the above are the only systems Masport used on domestic mowers

Commercials have a single tension pulley which is mounted in a slot through the top of the mower or a set of double pulleys making a tension clutch .

The variable speed transmissions use the actual cable as the anchor for the transmission because the cable rotates the entire transmission in order to vary the tension in the belt and thus change the speed.
Commercial vari speeds used a variable pitch pulley

 

[Chuzupop]

Thank you. I will look again. Thank you so much for your help. Sarah ?