YB100 Restore : 1980 model (100cc) :)

[Airhead]

it will clean oil/grease well, wear gloves and goggles of course. It is not as volatile as petrol

[slice]

If your looking to get the aluminium parts spotless then there is no alternative but elbow grease I'm afraid you will have to clean them as best you can with paraffin and then use various grades of wet and dry to complete the job, you can send them out for cleaning by an expert in linishing (ali polishing) but that is usually quite expensive as it's labour intensive, not sure you want to do this your self as the aluminium dust is supposed to be toxic. Have a look round where you live and see if anyone does this sort of thing locally.

[fakhir]

Week 3 updates (19-May-2013)

Hi guys, hope all of you are doing great. This time I wasted entire weekend trying to open up totally deformed screws with little or no success. Attached pictures show the progress. Since I don't have much material this week, i've taken quite a few useless closeups and macros LOL . Enjoy !!!

[fakhir]

Trying to remove the piston from the connecting rod:



First you need to remove both of the circlips retaining the gudgeon pin, also known as wrist pin or piston pin:



I used a nose plier to remove these circlips. Please note that these circlpis MUST NEVER be reused:



Closeup:



nose plier closeup:

[fakhir]

But unfortunately the wrist pin is stuck inside the piston and is not coming out no matter how hard I try. I even used force (which I shouldn't have) and I think I made a tiny scratch on the piston as well . Well, i'll probably replace it if the condition is too bad.

[fakhir]

Alright, FINALLY got the flywheel off. I must say it is a very powerful magnet: (As you can also see the piston wrist pin is stuck)



Flywheel closeup:



A little more zoom:

[fakhir]

Flywheel from another angle. Now the magnet puller is totally stuck in the wheel LOL:



Little zoom:



Further zoom:





Rusted surface on the wheel itself:

[fakhir]

Closer look at the flywheel magnets. There are a few signs of wear and tear but I don't know whether I should replace the flywheel or not.



Closeup:



There is rust on the wheel components but not as bad as rest of the bike. Still clearing this will prove to be a nightmare:



The flywheel outer case also looks pretty beaten up. I wonder if would be able to reuse it:



Zooming in. Rust but not too serious:



Bit more zoom:

[fakhir]

Now let's concentrate on the generator assembly:



Another angle:



Yet another angle:



Zooming in on the generator a little bit:



Coil closeup:



More zoom:

[fakhir]

Point system:



Some of the screws are in excellent condition:



Some screws are in a horrible condition, thank you Mr. mechanic:

[fakhir]

Got drifted away LOL. Wooden plank closeup: (This is oak wood i guess)



Closeup:




Okay, enough of the wooden plank closeups... Moving on...

[fakhir]

Hitting brick wall (totally deformed screws):

Ok so i've hit the brick wall. There are a few screws which are horribly deformed to such an extent that there is no way I might get them out without any physical damage to the casing:

I first tried impact screw driver. But the screws were totally jammed, rust won this time. Since screws were already deformed and soft, impact screw driver probably damaged them a bit further:

[fakhir]

Then I applied WD-40 and left it there for around 7-8 hours. Then I used impact driver again, some of the screws came off with a bit of working around. But few screws got soft and further deformed due to the high torque impact driver. I also hammered the area surrounding the screws but failed to open them up (using a hard wood of course. DO NOT use metallic hammer on the case directly)



Closeup:

[fakhir]

Some more damaged nightmare. Way too much rust and deformed screws, nuts and bolts. I mean:

Give me a break. This is my first ever project !!!!!!!!!!

[fakhir]

Concluding Week 3

Ok people, this is it for the week. At this point I am totally stuck, I don't know how to get those screws off. Following are some strategies I had in mind:

1) Heat areas surrounding the jammed screws using some kind of propane torch.

2) After that apply loads of WD-40 in the expanded areas and leave it there for a day or two.

3) Use a proper sized '-' or minus bit on the impact screw driver instead of '+' bit, drill a little bit '-' grooves and try minus impact driver again on the deformed screws.

4) I am not sure about using the hammer and chisel technique but that is also one option, I mean what ever that gets the screws off of the engine.

5) If still I can't get these open, I might have to borrow a drill from somewhere and try to drill out the deformed heads. That will hopefully detach the two engine blocks. In this case, will the front engine block come off easily while leaving screw shafts inside the other engine block? More work will have to be done to get the shafts out.

6) I REALLY hate to say this, but last option: "Take the engine to the mechanic "

Question:
If I apply option 5 (drilling the screws), what would be the worst case? Will I have to buy a new yamaha engine? If heads are drilled, I assumed that the shafts will still be in the casings, is it possible just to replace one of the case (other case should come right off as soon as screw heads are gone)?

Edit: I forgot to mention that the piston wrist pin is also stuck!

Thanks a lot for viewing. See you next week with more pictures and updates

[slice]

If your having real trouble getting the old screws out then one way is to drill the top of the screw off and just leave the shaft sticking out, then when you get it apart you can get a grip on the screw shaft and turn it out which a pair of stilsons or mole grips. As your not going to use them again it will not matter if you bugger them completely. DON'T use heat on old ali casings as they will warp or worse still fracture into pieces, just use enough force to turn the screw without putting to much pressure on the screw thread, believe it or not sometimes it's better to tighten slightly before you loosen the screw, soak in wd40 or penetrating oil for a few hours before you try to take them out. Good luck mate.

PS just clean up the magnets, wipe the rust off, they don't touch anything and they don't wear out like a mechanical item.

[fakhir]

If your having real trouble getting the old screws out then one way is to drill the top of the screw off and just leave the shaft sticking out, then when you get it apart you can get a grip on the screw shaft and turn it out which a pair of stilsons or mole grips. As your not going to use them again it will not matter if you bugger them completely. DON'T use heat on old ali casings as they will warp or worse still fracture into pieces, just use enough force to turn the screw without putting to much pressure on the screw thread, believe it or not sometimes it's better to tighten slightly before you loosen the screw, soak in wd40 or penetrating oil for a few hours before you try to take them out. Good luck mate.

PS just clean up the magnets, wipe the rust off, they don't touch anything and they don't wear out like a mechanical item.

In case if I drill the screw heads off, will the engine block come off easily? I mean the shaft threads pass through block 1 and then into the second block. If head is gone, how am I doing to separate the engine blocks? The shaft threads are locking BOTH the engine casings/blocks right ?

[Airhead]

the shafts are not locking the engine cases together, It's the srew heads that are doing that...6mm drill, just drill the heads off like my 'slice' says

[fakhir]

the shafts are not locking the engine cases together, It's the srew heads that are doing that...6mm drill, just drill the heads off like my 'slice' says

Thanks, I will try it out.

One more thing: How do I get the piston pin (wrist pin) out? I've already removed both of the circlips that hold the pin. But it is really stuck in there, I even tried to hammer it out softly (potentially ruining the piston LOL ).

[slice]

You probably need a puller to get it off the con rod if it will not just slide out, it MIGHT be possible to heat it and then give it a whack with a drift but there is always the potential to damage something else along the way if you do that unless you are really careful, as your splitting the engine anyway why not wait till you have it apart and then take it off of the crankshaft and deal with it in a vice rather than trying to sod about with it attached to the engine? That seems to be the best idea I can come up with for the moment maybe others will have a better idea. Just a thought why not just junk the con rod & piston altogether and fit new when you have it all in bits? Good luck Fakhir.