400 restoration project

[Barrie2777]

The lacquer thinner dissolves the old oil then I polish with fine steel wool. I prefer the patina of the old aluminum on my restorations.

[Barrie2777]

The cranks were done so so engine rebuild has started. The magneto bearing is put on the crank then that assembly is assembled to the motor half. Next the PTO bearing is put on the crankshaft. I use a gasket sealer on both sides of the crankcase gasket then assemble the two halves of the engine base. To put the bearings on the crankcase, I used a heat gun to heat the bearing up. When it is uncomfortable to hold, it has probably expanded enough to slide in place. Both these bearing dropped in tight to its shoulder. The same heat gun was used to heat up the engine halves and again heated until uncomfortable to hold with bare hands. Both bearing slipped on without effort. Align the halves and tighten the bolts 80% then in an hour tighten them all the way.

[Barrie2777]

with the two halves of the motor bolted together, the piston is assembled to the connecting rod. The arrow on the top of the piston should point to the exhaust port. This piston is one over sized due to the scratches on the cylinder wall that had to be machined out.

[Barrie2777]

The seals are tapped in gently. I oil the bearings, seals and rings before installation. It makes them slip into place easier and gives them that lubrication needed when the engine is first started.

[Barrie2777]

The new head is installed and tightened down with 18 ft-lbs of torque on the head bolts. I call this my NOS 252 with one size over piston. I am actually excited to see this run and how much power a new engine has.

[Barrie2777]

This photo is the same as I posted on page 4 indicating it is what you should see when the flywheel comes off HOWEVER it is not correct for a hus-ski motor rotation. All the parts are there, just not in the right spots. To confuse things, a JLO for a HUS-SKI should have the L252R indication on the engine tag. The "R" indicates right hand rotation when viewed from the PTO side but when you work on the stator plate and set the woodruff key in the good slot you are setting for a "L" rotation from the flywheel side. Set the woodruff key in the "L" position. The photo shows the woodruff key in the "R" position

[Barrie2777]

If that was confusing ...it gets better....put the flywheel in the opposite position...the "R" position.

[Barrie2777]

This is the tool I used to determine the BTDC setting for the position of the stator plate. The sparkplug should fire when the piston is 3mm BTDC. When this tool is screwed into the plug threads, its spring loaded plunger rests against the piston crown. The opposite end protrudes from the tool and is calibrated in mm. Turn the crank until the piston reaches TDC, then turn it backwards while watching the protruding gauge markings. Stop when you have moved the piston 3mm down or in other words 3mm BTDC. Since the spark occurs when the points open, it is here that the cam follower should be starting to ride up on the cam lobe. Rotate the stator plate until this starts to happen. A multimeter with audio is good to verify this. To check with a multimeter, remove the two wires connected to the points. Touch one tester lead to the screw the wires came off and the other lead to the other side of the points. By gently rotating the stator plate, you can easily hear when the points open +because the sound stops.

[Barrie2777]

Before you screw on the carb block, install the carb then find it won't draw gas you must ensure that the vacuum inlet hole is open and unobstructed to the base of the engine.( see the tip of the pointer in the photo) It is vacuum through this small hole that operates the diaphragm in the carb. This cylinder was from a motor which had seen some H2O which may have been the cause for this hole being blocked. I had to drill it out to clear the obstruction.

[Barrie2777]

This something I usually leave to a pro but ..hey, why not? The fist thing is to unsolder the two wires attached to the condenser. The three soldering guns I had would not melt the old solder so I went out to the shed to get the antique soldering rod which has been on the same beam for at least 60 years. I plugged it in and blew the breaker.. the wires in the plug were bare and touching. After putting on a new plug, it heated up and melted the solder. The old condenser is pushed out from the bottom of the stator plate. Due to the swedging which was holding it tight, the new condencer will not slide in. File off the old swedging so that the new condenser slips in, then with a punch pinch the condenser in place and resolder the wires to the top.