poor starting

[noddy 407]

well ...back in the garage with this castelgarden mower...new cables...new blade boss..as the old on had lost its locating dowels for the blade....new belt...but its a poor starter and takes a determined pull to start...had the carb off ..but will check that again..runs great once given a sniff of brake cleaner...or is it a bit too cold at the moment...are the tappets worth doing..what sort of compresion should I be looking for...im strting to like this mower..   what do you think..?

[Mick]

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. 

[noddy 407]

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

[Mick]

Nearly all engines have a automatic compression release, but that would work on the exhaust valve. If you have no tappet clearance on the inlet valve that will be the issue.  You're going to have to remove the valve and grind a tiny amount off the end of the valve stem until the correct clearance is achieved.  That said, if the valve face is badly worn that will need refacing or replacing, and then grinding back in.

[noddy 407]

  well ..sprayed the exhaust valve with oven cleaner after opening as wide as i could ,,and all seems better...it starts now..albeit on choke but i have no rev increase on the control...it does surge badly..so the carb came of for a clean and the 2 jets were cleaned with carb cleaner..like a tube and a main jet..cant see any others..but it looks very clean in there...sugestions?

[noddy 407]

well ..sprayed the exhaust valve with oven cleaner after opening as wide as i could ,,and all seems better...it starts now..albeit on choke but i have no rev increase on the control...it does surge badly..so the carb came of for a clean and the 2 jets were cleaned with carb cleaner..like a tube and a main jet..cant see any others..but it looks very clean in there.but still surges..sugestions?

[Mick]

Sounds like the fuel system still has issues, but I'd check that the seal between carb and inlet tube is good, and also make sure the inlet tube is sealed and tight against the engine block. 

From memory, some of these had a very light damper spring on the throttle shaft of the carb, this helps with hunting. Also have the revs set too high will cause them to hunt but you said it doesn't increase on the throttle so doubt it's that.

[noddy 407]

   done...the air filter case was not sealing on the carb face..needed a slight bend on the bracket that comes off the head bolts..starts first pull...at last...now to set up the correct revs and wait for some grass.....   many thanks for all yout help..cheers