1979 IT400 rebuild - Two steps forward, one step back

[GaryInVA]

After we go the cylinder off the engine, we pulled the engine from the frame. My son spent a lot of time cleaning up the frame after the engine came out.



Engine ready for the bench. I had my son make an engine box so we could start breaking into the engine. My son was so excited to see the inner workings.



Here's the engine box he built along with the engine with the left case taken off. The crank did not spin at all. Looking down into the lower end you see all kinds of corrosion. The cases would have to be split.



After pulling the flywheel I was really surprised at how spotless the ignition was.



Knowing that we had to split the cases, we flipped it over and pulled the cover off the clutch side. My son's eyes were as big as saucers seeing the inside the cases.

 

[Sparkyduc]

After we go the cylinder off the engine, we pulled the engine from the frame. My son spent a lot of time cleaning up the frame after the engine came out.

View attachment 344181

Engine ready for the bench. I had my son make an engine box so we could start breaking into the engine. My son was so excited to see the inner workings.

View attachment 344182

Here's the engine box he built along with the engine with the left case taken off. The crank did not spin at all. Looking down into the lower end you see all kinds of corrosion. The cases would have to be split.

View attachment 344183

After pulling the flywheel I was really surprised at how spotless the ignition was.

View attachment 344184

Knowing that we had to split the cases, we flipped it over and pulled the cover off the clutch side. My son's eyes were as big as saucers seeing the inside the cases.

View attachment 344185

I built a lot of stand like that out of 2x4 but I put a couple of 2x4s on the bottom laying down,one on either side which holds the stand off the workbench an inch and a half so that if something falls out of the motor you can fish it out and you don’t have to lift the motor off the stand to get it out

 

[atom4488]

Great to see your son engaged. Working on a bike (or anything else with Dad, for that matter) beats the hell out of what most kids his age spend their time doing. Mine did the same until they became mechanically independent by 16 or so.

 

[GaryInVA]

Still digging around on my phone finding pictures.

We split the cases and here is a mixture of 26 year old corrosion and all the oil I used to get the piston unstuck. Here's a pic of my son looking at the innards of a two stroke motor that isn't right.



The main bearings only turned if you really cranked on the flywheel. We figured it's going to need new main bearings and have the crank rebuilt. The inner surface on the small end of the rod was corroded and flaking off.



Here's a close up of the crank gunk.

 

[Its been a long time]

Still digging around on my phone finding pictures.

We split the cases and here is a mixture of 26 year old corrosion and all the oil I used to get the piston unstuck. Here's a pic of my son looking at the innards of a two stroke motor that isn't right.

View attachment 344485

The main bearings only turned if you really cranked on the flywheel. We figured it's going to need new main bearings and have the crank rebuilt. The inner surface on the small end of the rod was corroded and flaking off.

View attachment 344486

Here's a close up of the crank gunk.

View attachment 344487

What a great project for a youngster. Both my kids weren't interested unless it involved clicking a mouse or using a game controller.

 

[atom4488]

Still digging around on my phone finding pictures.

We split the cases and here is a mixture of 26 year old corrosion and all the oil I used to get the piston unstuck. Here's a pic of my son looking at the innards of a two stroke motor that isn't right.

View attachment 344485

The main bearings only turned if you really cranked on the flywheel. We figured it's going to need new main bearings and have the crank rebuilt. The inner surface on the small end of the rod was corroded and flaking off.

View attachment 344486

Here's a close up of the crank gunk.

View attachment 344487

Good thing that its the crank/crankcase that saw water contamination. The crankcase and its contents are more imminently rebuildable than a corroded gearbox, IMO.

 

[Charles13]

This is an awesome project! Only good will come from this