Engine tear down

Yesterday, I finally got the piston loose from the engine. I just decided to get out a hacksaw and cut the connecting rod in half. After that, one good whack on the sliced half of the rod connected to the piston got it un-seized. From what I can tell, the piston will be fine. But I will need new rings and a new connecting rod. The cylinder will be fine after a good cleaning.

After freeing the piston, I could finally finish splitting the engine case. I took a heat gun to the main bearing for a few seconds then lightly tapped the seem of the engine case with a rubber mallet and it started to slowly come apart. Then I realized the gear selector needed to come off. You may have noticed in my previous engine pictures, there was some sort of cement all over the gear selector. I guess the previous owner decided it was a good idea to do that instead of replace a gasket. Luckily, it all came off with a chisel and light hammer

taps. But the gear selector is so rusty that I might as well replace the whole thing.

I still don't have the tool to remove the clutch, so I got it as disassembled as I could and then just did a lot of cleaning with paint thinner and a wire brush and rags. You would really be surprised what a little bit of elbow grease can do to these old engines. You can really bring them back to looking just like new. And it really isn't hard work, in fact it's pretty relaxing. If you are doing a restoration, do yourself a favor and opt to rebuild your own engine instead of buying a new one or having some one else do the work. It is so rewarding to see how everything works and bring all the luster back into the heart of your scooter. When I split the case, there was rust, grime, sludge, and dirt everywhere (see pictures). I'm not done yet, I'll post pictures in the next few days of how clean it all is when it's ready to be put back together.

I can't get to the clutch assembly yet, so I can't tell if anything in there needs to be replaced. As far as I can tell, everything is alright. The bearings are even in pretty good shape. But I would still like to replace them. Does anybody have any tips for getting those suckers off? I can't get to the clutch side one yet, but I am having trouble with the crank side one.

That's all for now, be on the lookout for some clean engine photos in the next few days.

Ciao.

How to clean your engine cases

I recently read that some folks like to use "oven cleaner" to clean up their engine cases. Warning! It's a bad idea!!

Also, don't polish your engine cases. Hard to keep clean. Not original either. Just clean them up or bead blast them, which is what I did.

I have had this discussion before with my mentors and just emailed them to confirm that I was right.

Here's what Tom G. said:

Bad idea.

Cases are aluminum, and most oven cleaners are
lye-based (caustic soda).  Lye reacts with aluminum.
Frankly, I don't know if it weakens it or not
(probably not upon temporary surface contact), but it
does leave dark stains on it.  Ugly.

Scrape as much as you can with a plastic, wood, or
even metal scraper, and then wash the residue off with
solvents.  Not necessarily paint thinner either, but
ok to use it if you like.  Gasoline is cheap (but
explosive!), and there are proprietary parts washing
solvents out there which are less combustible, and
have additives to deter evaporation.

Here's what Christopher M. said:

I agree with Tom. If you buy parts washer fluid at an auto parts store,
avoid the Purple Power stuff. It creates some sort of effluoresence on
aluminum. Not sure if it eats metal, but it gets ugly. Easy to brush off,
though. I like the paint thinner that is listed as reduced odor. It still
stinks, but not as much as the regular stuff.