How to measure and fit a drive belt

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How to measure and fit a motor belt

belt12 The picture on the left shows the parts of the sewing machine mentioned in this tutorial.

You will need the following;
Screwdrivers, or spanners to fit the bolts holding the motor and bracket.
A length of string or cord - at least 45cm or 18 inches long.
A marker pen
A ruler or tape measure

If you already have a new drive belt for your machine, go to Step3.


Start by fitting the motor and bracket

The motor can be moved up and down by loosening the bolt holding the motor bracket to the machine.

The motor can be moved in or out by loosening the bolt holding the motor bracket to the motor so there is space between the motor and light, and the side of the machine.

Some motor brackets do not have this adjustment.
To measure for a new belt, put the motor about half way up it's travel, and move it in towards the body of the machine, leave 3-5mm of space.
belt6 Look from above to make sure there is clearance between the motor and light, and the body of the machine.


Take a length of cord, and put it round the motor pulley and the belt groove on the back of the handwheel.
Pull the cord tight, and hold it between thumb and forefinger, then mark across both ends of the cord with a marker pen.

Measure the length between the two marks with a ruler.

To see if we have a belt for your machine;
Click Motor Belts in stock

Step3 Fitting the belt

When you have the right belt for your machine, undo the bolt holding the motor and bracket, slide it up as far as possible and tighten it enough to hold the motor in place.

Put the belt over the handwheel and ensure that the belt is in the pulley at the back of the wheel.
Pull the belt over the motor pulley, it should be a loose fit.
Undo the motor bracket bolt and slide the motor and bracket down then tighten the bolt and check that the belt can be deflected about 1cm with your finger.
Adjust the motor and bracket up or down until it has the right amount of slack.
You may need to do this a few times to get it right.


Look at the belt from above to make sure that the two pulleys line up. If they don't, the motor pulley can be moved along its shaft.
The pulley is locked on to its shaft with one or two grub screws, undo them, and move the pulley along the shaft until it is in line with the pulley on the handwheel.
When the pulleys line up, tighten the grub screw, or screws up.
After doing this, check the belt tension and adjust if needed.


The motor should be ready to try, first try it with the clutch undone, so only the handwheel moves.
Do up the clutch, ensure that there is no thread in the machine, and raise the presser foot, then try running the machine.
My address is:-
Helen Howes
Helen Howes Sewing Machines
4, The Raveningham Centre, Beccles Road, Raveningham, Norfolk, NR14 6NU. United Kingdom
01508 548137
From outside the UK dial:- 0044 1508 548137
07914 676182
I'm open 11 till 5 every day except Tuesdays and Wednesdays