This question, isnt just about swapping engines, but about swapping an engine that drives a rear cylinder (by cylinder, I mean roller) with and engine that drives normal wheels. 

I have a Hayter mower with a rear cylinder drive.  The engine is a Tecumseh BVS 153 ES.  The rear cylinder is connected to the motor via pulley that protrudes horizontally from the side of the engine which drives a belt that is connected to the side of the cylinder.  This is different from a wheeled mower where a pulley on the vertical blade axle drives a belt that is connected to a pulley on the gears box on the rear axle.

I have a spare motor with the latter arrangement. 

QUESTION = Are they nterchangeable.

Thanks all for sharing any thoughts.

Works perfectly - but see the the other post which describes the problems I am having finding a replacement for the Dellorto FCH20 13A carburetta.

It turns out the one i bought is too tall.  It doesnt allow for the top plate to be screwed down properly.

https://www.ebay.co.uk/itm/156182863955   - this is the too tall one. 

Back to drawing board. 

Every day is a learning day - I had to looked up the meaning of UNC - so here I am a wiser man.  I also found a UK supplier of what I think is the same screw - will let you know when it arrives.

Hi everyone,  I am looking for a part for a Tecumseh that I am working on.  It is the screw that connects the pipe for the carburettor into the body of the machine.  From what I can google, it is part number 650451.  But I can only find it on a US based site and they do not ship to the UK.

Does anyone know where I might find one. 

Some photos whow the type of screw i am looking to find. 

Thanks all. 

A bit of futher information. 

If I have read the lable properly (its a bit scratched) the engine model number is "BVSR 153  ES E – 41011C S9081C".

And the markings on the carburetta is "FHC020 13A" - I just cant find that on google. 

Thanks all.

Hi everyone.  New to this forum and delighted to be in the comapny of great small engine enthusiasts who are so generous with their expertise. 

I have a Hayter lawnmower with a Tecumseh BVS 153 engine on it.  It is old and has not worked for a long time - but the deck is in great condition.  When I spray of bit of juice into the spark plug chamber, it fires up and sounds quite healthy.    But the carby is in a dreadful state and I need to replace it.

The carburetta is has markings on it "Dellorto FHC20 13A".  It doesnt have a primer bulb on it.  I have googled and cannot find anything that look like it.  Most Tecumseh Carbursttas that I see do have primer bulbs.

Will it be ok to simply replace a non-primer carby with a new original Tecumseh carby with a primer bulb -is it a straight forward swap?