Morning....well back in the shed with a non starting castlegarden /sv40 engine....will start with a sniff of 'easy start'..but you have to yank it like your life depended on it starting..dont like doing that....so..back to basics...new fuel ok..carb clean..new plug..sparks well..coil gap ok...valve cover off.head off..bore ok decoke...all looks ot be working in the right order...ie valves closed on compresion..(tdc)..compresion check....using electric drill on pull start location..after 30 seconds...25psi..does this engine have a low compresion start up also..cnt find a gap on the inlet valve tappet  but a gap on exh...what am i missing?..ps i dont have a leak down tester...sadly

Inside The Factory

Paddy McGuinness, Cherry Healey and the BBC team visit the Hayter factory in Hertfordshire home to the legendary Hayter Harrier lawnmower.

I found it quite interesting especially as I've been there a couple of times over the years, it's changed quite a bit from when I was there last.

Missed it? Watch now on BBC iPlayer. https://www.bbc.co.uk/iplayer/episode/m002qwyl/inside-the-factory-series-10-lawnmowers

Hi greenkeeper, and welcome to TGMForum.

Unfortunately I know very little about John Deere machines. I've probably only worked on a handful of walk behind JD machines over the years. Hopefully someone will read your post and chip in with some advice.

hi considering buying my first ride on lawn mower.
its a john deere lr 135, bit age about it. looks tidy
anybody had any experience of them ?
thanks

Was it the owners manual for that machine you were looking at at? The manual I have here gave the figures above.

When they said 0.12 and 0.15 I suspect they were talking metric not thou

0.12 = 4.7244 thou
0.15 = 5.9055 thou

Just get the piston at TDC on the compression stroke or just past, and set the to 4 and 6 thou it should be fine. 

Quote from: Mick on January 12, 2026, 07:58:29 PMHi Mike

Model: DG450 Valve clearance (cold)

IN:0.06+0.02mm
EX:0.08+0.02mm

Hiya mick I did ask cobra before I decided to create a topic they just got back saying "The correct settings for the intake and exhaust is 6mm back from top dead center on top dead center where the valves do not move with a 5 thou gap on both valves" and manual says 0.12 - 0.15 so I'm a bit confused.

Thanks mick

Hi Mike

Model: DG450 Valve clearance (cold)

IN:0.06+-0.02mm
EX:0.08+-0.02mm

Hi all does anyone know what the DG450 valves clearances are please. Thanks

The biggest problem I see with these on a regular basis is the throttle cable needs pulling back a bit so it pulls the choke on fully.  Sometimes they don't quite close fully which gives the issue you're having.

Just undo the cable clamp at the bottom and move the cable back about 1/4" and see if it helps.