Restoring Yamaha 100cc (YB100, model:1980)

[syedmughees]

one of my favorite D.I.Y thread
nice work done
waiting for more updates

[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 :S . 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. We will look at it in great detail later on:

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]

[U]Hitting brick wall (totally deformed screws):

[/U]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 :S :S !!!!!!!!!!

[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 :S" (any good mechanic here in Lahore for this kind of stuff?)

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

[N0m1]

Best of Luck.

[MUNZALEEN]

Went to bilal ganj and bought some tools. The pressure gauge and impact screw driver are two very cool tools that I've ever owned:

Another angle of the bike:

Yet another angle:

Looks like it was a heaven for spiders:

Brother nice project but petrol of this yamaha maximum to 30km/litre
would you like to share the price of whole toolkit showing in pictre without the pressure gauge please

[racer7]

Very nic project but a little slow.

[vickytulla]

dump the tension ... and to open the screws which just brought you to halted position can be Opened easily and all you need is hammer-able (-) screw driver ... remember the screw head is soft so as you would hammer it on head screw driver will penetrate into the screw head now hammer it to Opening side (anti clock wise) don't worry that screw is getting damages because its expired already ... it will hope fully open or its head will chop away in both cases two engine blocks will be separated ...

suppose screw head has chopped away and engine is open now you want to get the left half of screw out just take it to welder he will do the magic just ask him to get it out with damaging they know what to do ..

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 :S" (any good mechanic here in Lahore for this kind of stuff?)

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

[mfdarvesh]

Hopefully this technique will work
Once I broke the head of a Bolt and lathe man do that trick, he drilled a hole in the broken bot and then put a another long bolt and then opened that broken bolt ...

dump the tension ... and to open the screws which just brought you to halted position can be Opened easily and all you need is hammer-able (-) screw driver ... remember the screw head is soft so as you would hammer it on head screw driver will penetrate into the screw head now hammer it to Opening side (anti clock wise) don't worry that screw is getting damages because its expired already ... it will hope fully open or its head will chop away in both cases two engine blocks will be separated ...

suppose screw head has chopped away and engine is open now you want to get the left half of screw out just take it to welder he will do the magic just ask him to get it out with damaging they know what to do ..

[faizandawood007]

dump the tension ... and to open the screws which just brought you to halted position can be Opened easily and all you need is hammer-able (-) screw driver ... remember the screw head is soft so as you would hammer it on head screw driver will penetrate into the screw head now hammer it to Opening side (anti clock wise) don't worry that screw is getting damages because its expired already ... it will hope fully open or its head will chop away in both cases two engine blocks will be separated ...

suppose screw head has chopped away and engine is open now you want to get the left half of screw out just take it to welder he will do the magic just ask him to get it out with damaging they know what to do ..

Yup i have tried this method before it works but u have to make sure that the screw driver has penetrated enough that i won,t slip again all u need is to make a cut in the bolt u can do it with hammer and screw driver or small drilling machine like this


it u can work with it easily with different angles and it comes with a lot of tools and can make a cut in any bolt so that screw driver can fit in easily
But try not to buy pink one