PROJECT 900

I think you'll be sufficiently ahead of the game if you retrieve the dropped parts and facilitate the repair through where you made the cut to weld it up and be done with it.

You are amazing.
I hope you get it backk together and it Starts right up and don't leak.

 

I would suggest a removable / screw on cover as opposed to welding the top back on - you might have some contaminants fall into the case during the welding process that could be terminal for the motor.

Plus, welding oil contaminated metals is not a very good idea (ask a commercial welder 8O )

All up - it's a pretty clever mod if it works :wink:

 

if you ever need to do the valves

 

Polock, put my bike back together right now. :evil:
Found the reason for the slipping starter clutch, cracked outer race.
FYI. symptoms were: s clutch slipping out when engine cold, once it had been running, no problem, the extra stress of a cold mill just forced the crack in the outer race open not allowing the rollers to grip.

 

Had one that cracked like that on a CB1100F I had. Was told it was from a back fire while trying to start it as the timing was off.
Fortunately, it was located just under the LH side cover .

 

All looks awfully familiar... Just as I said earlier Yamaha use this same design on a lot of models from this era and the material is just not up to the task.

 

Looks like it came out of a Virago. (The big V-twin kicked back a lot harder and more often.)

Apologies, Wiz, I did't realize it was an incision, thought you just took a big hammer to it. Should never have doubted you.

I would take the piece you cut out, get a few strategic tabs welded onto it and screw-mount it. You could add tabs under one side, and a couple on the outside of the other side, and screw the outside tabs down. Smear Yamabond into the crack and call it a day.

Much easier to weld tabs to the piece in your hand than try to weld on the motor.

 

I'll rain on the parade.
Devils advocate.
What have you?
I bet if you don't weld it, ... It will leak.

The Piece you excised from the bottom of the Case DOES NOT fit the space where it was excised from any longer.
It's .00245 Inches too small.

What is it they used to day about Machining a Part after you have measured ... someone else has measured ... and the Foreman measured ... with all three measurements being the same before you make the pass on the stock making the cut, ... because if you must make a Piece that will fit.

A miss is as good as a Mile.
The Piece you want to put back into where you took it from is two and a half miles too small.

It Does NOT fit by the WIDTH of the Cut-off Tool used to make the cut.
What the width of a Dremel Cut-off Wafer? 20~30/1000ths.???

 

This is how it will be done, I need to form 2 mating surfaces to have any chance of a bolt on 'cap' not leaking, the cut aperture will form one face & that face will be covered with tape, the 'cap' bolted in place with set screws & internal plates, then the gap will be filled with 'Q' bond (which sets immediately and hard enough to drill & tap, if required, but that's not it's role in this instance) the 'cap' can then be unbolted & dressed up, the tape removed & replaced with an RTV gasket. That's the plan..........

 

I agree Rick, and also the torque stresses of the transmission case ride up to that area.
Imagine the stresses of pulling a wheelie, and a huge hunk of the tranny case is just goobered in there, (and no offense to Wiz's incredible talents).
Remember, the oil pan is also open.

That "Ally solder" is supposed to be stronger than the regular metal, and flows in at 600* to not ruin everything with heat. (270C??)

 

I don't think so. I went back and looked at where he cut it, and it looks like any stressed areas are on either side of the new aperture. As long as it doesn't leak it should be fine.

I strongly suspect Wiz is not a wheelie kinda guy.

 

Time, pulling a wheelie puts stress on the transmission & final drive, after start up the generator shaft is just spinning..........

 

I hope so Mr Fitz, but did you take into consideration that it's shaft drive, and the torque of the driveshaft has to go somewhere??

Maybe we should consult Schooter, the engineer??

OK, I'm officially and respectfully not liking this. No glue.

 

Wiz, I would give you a spare engine case, if you were only closer.

 

Thanks for the thought, Time, but don't stress, havn't you seen those working engines at the science museum with great chunks of the casing cut away so little Schooters can see the works?

 

I think you are abandoning "Pragmatic Engineering" for the sake of a Vanity-inspired endeavor.
Take a look at the Project with the sensibility of Fail-Safe Engineering.
You won the Grand Prize. Pick anything off the Top Shelf.
You deserve to have this Technique named after you like the great life-saving techniques named after Doctors who experimented and now have operations named after them.

Weld it closed and take a bow!
Submarines don't need screen doors.

Your intellectual development of this Repair Technique does not require further development beyond removing that portion of the Case, gaining access to the worn-out or broken parts, facilitating the repair >>> SAVING 30 HOURS OF LABOR <<< and replacing the portion removed by carefully welding the piece back in place.

It don't git no bedder then nat!
It don't get no better than that!

Furthering the process "Because you can" only serves to advance the whole thing beyond the Point of Diminishing Returns.

Button that job up and take credit for doing it right; because the next guy in line is going to weld it and poke fun at you for wasting a lot of time getting the project finished by making the Piece removable only to have it leak.

 

Off topic a bit, here's a sleeve valve motor from the 40's. The piston slides in a moving sleeve, which slides in YET ANOTHER moving sleeve, which slides in the bore. The 2 sleeves have ports which align to allow the intake and exhaust events. The sleeves slide at half the piston rate. There are no poppet valves or cams.

The preservation society didn't have the heart to cut up a relic, so they totally replicated this working model on display at Hershey PA. The gold connecting rods move the sleeves.

 

Thanks Schooter, that was from me.

 

My idea for taming the springs & rollers while they get installed, pour hot wax in there & put in the 'fridge, when all the parts are in place, warm up the hub unit, with an ally' foil shoot under to catch the melted wax.

 

I've just read this through, start to finish, (quiet day at work!). Lovely job there Mr Wiz. I am inspired.

Felt like a blind man at a strip show till Page 26 though!
PS What do they sing out at Saudi Arabian strip joints ?
"Show us yer face"

Love this site and have learnt a whole lot since finding it. Like the definition of "annealed" for instance. As an analogy it's kind of like going to the pub (softening up) after going 28 days without alchohol, (hardening up while at work). Quenching IS necessary.