Skip to main content
Collection, Preservation and Display of Old Lawn Mowers

MK3 Anzani Villiers 150cc Lightweight; no torque

Enter a word or two to search the forum section and click the Search Forum button.

Villiers 150cc Lightweight Engine in a MK3  Anzani Lawnrider   

Finally I have got the engine running after a carb clean and ignition timing reset.  The engine will run but it has no torque, it will just power the lawnrider  on a hard surface, but not on grass. 

My questions;

Can anyone suggest what to look at next? my guess is a compression test and probable head off to decarbon and check valve seating. Can anyone suggest anything else before I remove the engine (Yet again!). 

What would be a good compression test reading ? the Anzani/VIlliers manual does not state a compression ratio 

Has anyone used the chemical decarbon liquids that pour in the plug hole with possitive results?  

Thank you!

Martin

Forums

wristpin Fri, 31/05/2024

Decarbon liquid is what we used to call Snake Oil - waste of time !
Head off , clean and reface the valves, skim the seats , lap in and set the clearances.

MartinH Thu, 06/06/2024

Anzani Cylinder head boltsAnzani Villiers 150cc engine. The cylinder head has 4 steel bolts and 4 phospher bronze bolts. What are the correct locations for the phospher bronze bolts? Attached photo shows locations before removal, but I'm not sure this was correct. Also photos of other similar engines suggest different lications. Can anyone advise please? 

sparkymike Sat, 08/06/2024

Perhaps the bronze bolts were supplied by manufacturer as a replacement when steel bolts rusted into the cylinder head  ?         Obviously they must have been more expensive than the steel ones.Is cylinder head steel or alloy ? Just a thought.

Mike.

MartinH Sat, 08/06/2024

Re 4 Bronze bolts, the head and body are both alluminium. The parts manual shows  two different  part numbers each for a set of 4 bolts, one set for the cylinder head, another set that clamp a cowl on the head, these also go through the cylinder head clamping it to cylinder. If one set is bronze and  the other steel then it means the bolt types are alternating around the head, which just seams odd considering the different bolt metalic properties. I can understand if the bronze bolts are used round the inlet and outlet valves as these would be the hotter side of the cylinder head, but this is not relected in the two different sets of partnumbers  I may be giving this undue procrastination (!) but it would  be nice understand the manufactures design.

wristpin Sat, 08/06/2024

The bronze bolts are referred to by Villiers as Barronia bolts and were original fitment.