Passport C70 - Water Damage

[milesoffun]

Thanks for the add!

I have a what was a "cherry" C70 before hurricane Sally pushed water under my house! Water got up about 12+-", I thought the piston was stuck but after taking the head/cylinder off, it is free.

I then took the left hand cover (flywheel) off and found rust on the electric starter chain and flywheel sprocket (since is leans to that side on the kickstand). I've got it to move by hand but at a certain point it stops - I can force it past that spot but the manual kick start slips and will not move the flywheel at all.

I was trying to avoid splitting the case. It's sitting with a combination of acetone and ATF fluid but it does not seem to be helping. Any ideas what might be holding it up and possible things to try? And if I have to open the case, any advice?

Thanks!

 

[-Nate]

Remove the spark plug and see if it's rusty / corroded .

KROIL is the stuff to use to get it unstuck, in 55 + years of wrenching nothing else ever came close .

Best of luck and keep us posted .

Because there's rust inside the engine it really needs a complete teardown and overhaul _BUT_ in my many decades of Farm and junkyard works I have discovered you can often save an engine like this by installing a rare earth magnet and cleaning it often as you get it running and do multiple hot oil changes .

There's a centrifugal oil filter in the center of the AutoClutch, open and clean it well .

 

[HydeParkBill]

I don't think my family's 1971 CT70 has been started for at least 25 years. It was always garaged. I'm starting to refurbish it and pulled out the plug and it is completely rusted. Why would that happen? I guess it's a complete engine disassembly, vapor honing, carb rebuild, etc.? More than I anticipated!

Thanks,
Bill

 

[-Nate]

Often when the engine stops it does so with a valve open and this allows fir to enter the cylinder .

If you're near the ocean or anywhere there's fog or rain, this means even inside a dry shed/garage/barn it can stick .

Good luck with it, there are pretty simple if precise engines and respond well to any sort of care .

Please keep us posted .

 

[milesoffun]

Thanks Nate - I appreciate the suggestion on Kroil. Not sure what I did, but she is free! I did remove the clutch cover and things in there looked to be in good condition, with no rust. And I can peak in the crankcase from cylinder base, it all looks good with no rust. The most rust seems to be on the left side - when I took the left side cover off, there was rust around the alternator in the cover - since this bike only has a kick stand on the left side, it looks like water sat in the there as it was leaning on the stand. But I think the alternator parts can clean up with a bit of work. And I'm not sure that would have caused the "rub" noise at a particular point because I had that cover off for days before she started turning freely. Maybe I finally sprayed with oil in an area that helped - I'll keep looking. I'm waiting on a carb and gaskets at this point, but she is pretty darn smooth at this point! Again, thanks - I will let you know what happens when I put it back together! Sally was a real bummer for me - I had the C70 along with a 68 CT90 K0, a 71 SL125, and a 2003 xr50, as well as 2 GL1100's - all were stuck. But as of today, I have all four of the small bikes freed up!!! Not running yet - but I'm a heck of a lot closer!

 

[-Nate]

Take your time and DO NOT touch the alternator wires with anything but a toothbrush .

The alternator rotor is easy to remove then it can be cleaned of rust with #0000 steel wool, you'll need lots of clean paper towels to get all the rust SWARF off, work gently and carefully .

Squirt some ATF or thin machine oil ebtween the valve springs to wet/lube the valve stems before you rotate the motor much .