Friday, January 10, 2014

1st Little Briggs Assembly

I have opted to put #1 back together and see if it runs well with its scored cylinder.   But first I have to finish cleaning the internals and lap the valves.

From a box of parts back to an engine if all goes well.  First the crank, tappets, and cam need to go in so we can check valve clearances.  Next in go the valves and they are both at .007 so we will call it good.  Cover the entire thing to keep it clean and call it a day.

Saturday Jan 11th

Today I expect to install the piston and connecting rod but can not tighten it or the head until my torque wrench arrives on Monday.  A hose clamp lubed with petroleum jelly works as a ring compressor for this engine.

Monday Jan 13th

The rod and cap are on.  Need to dig for a 7/16" 3/8" drive socket to torque it.  Forgot to lube the rod journal so I had to do it twice.  In cool weather 30W engine oil sticks like assembly lube.

Tuesday Jan 14th

Torqued and locked the tabs on the rob bolt.

Wednesday Jan 15th

Pulled an electronic magneto off a donner 3.5HP mower.  Torqued the head using anti-seize compound which also acts as a lubricant. Torquing is somewhat different then without.  I may back them out and go over it again tomorrow.

Lapped the flywheel.

Friday Jan 17th

Cut a new gaskets for the side cover and the carburetor.  The side cover is on.  Carb goes on today.

To cut the gasket I started with an image on the web.  I scaled it as close as I could but it was a bit too small in on dimension.  A second adjustment got it just right.

Got everything together but the shroud.  I had a bit of a problem getting spark.  I swapped in the coil from Little Briggs #2 and sanded on the flywheel a bit more.   Fairly sure it was the sanding that did the trick.   Spun it up with the drill and got it to fire with a bit of gas dribbled into the carb.  But it blew the starter clutch apart.  The smoke from oil used to assemble it rolled out the exhaust.  It did not run long but I think it sounded good.  I wish I had been recording it.  Live and learn.

Tomorrow the plan is put the clutch back together, install a shroud (may borrow the one from the red briggs), and see if it will run with gas in the fuel tank.

I have 2 fewer shrouds then engines.  Since I plan to use one for parts that leaves me one shroud short.  But it would be nice to put a pull start on the generator so that leaves me two short.

Saturday January 18th

Last night it got down to 17F and I am use 30W oil in these engines.  So I brought this one inside and it spent the night next to the door in a small tub.  The expected high is 65F but the wind will be over 20MPH.

Started the day by filling the tank with gas.   Primed the carb once to get some fuel pumped into the reservoir in the tank.  It ran well but I need to put the air governor back on and rig up a throttle.  Need to search from some original like parts.

Here I need to note that this one is running with the diaphragm and spring from the red engine #??,  The diaphragm form this carb was fossilized.   The one it is now using was stiff but came back to life somewhat after ultrasonic cleaning.   If I was going to put this engine into service I would gift it with a new diaphragm and spring but this one is good enough for what I am doing.  What is that ?

Swapped the coils back.  It now has the one from the donor mower which was cleaned in the ultrasonic cleaner.   This is proof that for at least one coil this is an OK thing to do.

It was sort of funny.  I had the this engine running on the front lawn and the breather tube fell off.  When I took it back to the bench I found that the top carb bolt was out about 1/3 inch.  So I retightened it and the bottom one.   Thinking anti-sieze on the muffler and maybe a bit of lock-tie on the carb.

Pulled the magneto back off to install the governor vane and throttle linkage.  It is still missing the friction rod and linkage.    Two of these setups can be had on ebay for $5 + $2.50 SH.  Should be on order.