pycoed
Member
- Location
- Pontarddulais, UK
My son dropped off his Mountfield lawnmower with a B&S Sprint engine - the one with a plastic carb on top of the tank - which wouldn't run despite the administrations of himself & a neighbour.
I remembered having bodged up the diaphragm with some elec tape a couple of years back, telling him to buy & fit a new one...
So of course when I found the red tape showing under the carb, cursing the son & heir, I just ordered a new gasket & diaphragm, so began the saga:-
1 Carb diaphragm was knackered - renewed with new gasket
2 Carb O ring seal to inlet manifold was iffy - renewed
3 Carb "bowl" was dirty - in top of tank - cleaned out
4 Dismantled carb & cleaned all jets - a masterpiece of value engineering actually
5 Checked coil - was slightly rubbing on flywheel - reposition & set clearance
6 Check plug for spark - fine
6 Still wouldn't effing start
7 Have a good think - plug was soaking wet...
8 Look for different plug - only one found that would fit was an old Kohler 8hp plug.
9 Check Kohler plug for spark - OK.
10 Fit Kohler plug
11 It starts!!!
12 Cut grass -OK but it won't shut off, so pull plug lead to shut down
13 Fix cable shut off so dead man's handle works.
14 Cut some more grass - all fine & shuts down properly.
15 Write out bill to send to son
Now, I've messed about with engines of many sizes since about 1964 & never have I found the issue to be the plug(s). Everyone always says - "Oh! Change the plugs first" but I repeat I have never had a faulty plug. Caps, leads, distributors, coils , points, CDI units, sensors? yes by the bucketload, but this is the first time in 56 years I have personally found the plug to be the issue. I even have a Danarm brushcutter bought new in 1979 with a Kawasaki 35 ish cc engine that is still on the original plug. Ditto Wheelhorse tractors from 1970's. That'll learn him for putting a Briggs & Scrap'em genuine plug in it
I remembered having bodged up the diaphragm with some elec tape a couple of years back, telling him to buy & fit a new one...
So of course when I found the red tape showing under the carb, cursing the son & heir, I just ordered a new gasket & diaphragm, so began the saga:-
1 Carb diaphragm was knackered - renewed with new gasket
2 Carb O ring seal to inlet manifold was iffy - renewed
3 Carb "bowl" was dirty - in top of tank - cleaned out
4 Dismantled carb & cleaned all jets - a masterpiece of value engineering actually
5 Checked coil - was slightly rubbing on flywheel - reposition & set clearance
6 Check plug for spark - fine
6 Still wouldn't effing start
7 Have a good think - plug was soaking wet...
8 Look for different plug - only one found that would fit was an old Kohler 8hp plug.
9 Check Kohler plug for spark - OK.
10 Fit Kohler plug
11 It starts!!!
12 Cut grass -OK but it won't shut off, so pull plug lead to shut down
13 Fix cable shut off so dead man's handle works.
14 Cut some more grass - all fine & shuts down properly.
15 Write out bill to send to son
Now, I've messed about with engines of many sizes since about 1964 & never have I found the issue to be the plug(s). Everyone always says - "Oh! Change the plugs first" but I repeat I have never had a faulty plug. Caps, leads, distributors, coils , points, CDI units, sensors? yes by the bucketload, but this is the first time in 56 years I have personally found the plug to be the issue. I even have a Danarm brushcutter bought new in 1979 with a Kawasaki 35 ish cc engine that is still on the original plug. Ditto Wheelhorse tractors from 1970's. That'll learn him for putting a Briggs & Scrap'em genuine plug in it
