Webb 24

A bit hard to tell from here, but my first thoughts are, is something binding ? Cylinder set too hard on or the rear roller drive bearings seizing up ?

Both the above plus the arms that carry the tensioner pulley can partially seize and not allow it to tension fully. If you look at the spacer tube between the arms where they pivot there  is a lube hole that gets neglected.  If you put a finger  on the pivot bolt head and operate the clutch and feel the bolt trying to rotate, its seized!

Thanks Hortimech but no, all free as normal and nothing different from machines i have had in the past.

Thanks Wristpin

All tension parts free and lubricated - arms move freely and northing seized or stiff.  New belts same as old belts. Spring seems good and have tried a couple of different ones. It's quite strong and hard to pull clutch lever against the tension but not necessarily the correct one.  Will try to source an original or compatible one to make sure.

The only thing left to suggest is to make sure that there’s a little slack in the clutch cable when in drive.

Please post an nice straight on image of the belts and pulleys with the drive engaged.

The original belts were, I believe, a matched pair of Dawson Speedona fabric covered A38.5 part number W28420

Sorry for slow response, have been away for a couple of days.  Photo attached in drive mode. 

 OK, through the wonders of being able to enlarge your image on the iPad it is revealed that the belt keeper to the left of the top pulley is incorrectly positioned . It should be rotated anti-clockwise to approximately the 2 o’clock position so that with the belts engaged - under tension , they are not touching it .  With the belts out of drive they will then touch it and it will aid them to spring off the top pulley to give a clean declutch.

I know that from the shape of the keeper  this sounds somewhat counterintuitive  but as strange as it may seem it is correct.  Back in the day we used to see many 24s exhibiting this error.

I do have, and have posted details in the past , of the Webb instructions confirming the correct set up.

EDIT. I should add that if anyone is in possession of the pink covered Owners Handbook entitled 24" Motor Mower Model No. 271 the illustration on page 8 shows the WRONG position for the keeper!

May also be wrong in later handbooks.

Thank you Wristpin, i will try that tomorrow.  Do you think that will improve the drive, though and grip from the drive pulley, which is currently slipping, being the problem.  Maybe as you say, it's counter intuitive.  Thanks again anyway and will let you know.

If you’ve not already reduced those belts’ ability to perform properly by effectively running with a brake on them , you should see an improvement . However if if they are now half s*****d , perhaps not. Throw them away and start again , but remember that the new ones will stretch and need to be kept in adjustment.

When you’ve set that keeper to be just clear of the tensioned belts make sure that you still have a bit of slack in the clutch cable. Removing the pressure of the keeper will allow the spring tensioned jockey pulleys to take up the slack in the belts  and in doing so they will “use” cable adjustment.

Also, you do need to use a matched pair of good quality belts. Two individual belts , even though marked with the same size , are not as good.

Just in passing, it appears that you have not got the oiler access hole on the outside jockey wheel washer positioned so that you can access the oiler on the pulley spindle bush to give it the occasional drop of oil. Also, don’t forget that oiler on the spacer between the jockey support arms.

I had a 24 that started life with a Villiers 150cc Lightweight that the owner had run out of oil and fitted a 4HP Tecumseh. I replace that with a Briggs  5HP which made it into the machine that it always should have been.  It used to do a quarter of an acre a week and a belt set would last one and a half seasons; unlike some of my customers who would get through a couple of sets a season!

It's been a long time since I changed the angle of the belt guide/retainer and I have only just tried it.  Unbelievably it works and there seems to be a much better grip on the pulleys.  Thank you.

I have another query on a Webb 24 nd will start another thread.