The Free "B", a 1971 resto redux

[gggGary]

Ooh a CHALLENGE!

:Use a mild solvent (mineral spirits) to free them from the oil.
:back at it with the vacuum.
: piston near TDC, open exhaust valve, blast with compressed air in the plug hole. Send em down stream.
: tape on a stick.

 

[Jim]

piston near TDC, open exhaust valve, blast with compressed air in the plug hole. Send em down stream.

I've done that numerous times.... works great. A skinny tipped blow gun, open exh valve and go crazy with the air.
If it doesn't blown 'em out the exh, it should move it to a more favorable location to grab 'em with a grease tipped stick.

 

[Jan_P]

OK Thinking out loud
The other day I Used a big strong Magnet I believe salvaged from Pioneer Loudspeakers i Damaged with a Shorted HiFi
Holding against an Allen wrench and the other end gets magnetism .Picking up the plunger in neutral detent gearbox
Bale wire ?

But if not Magntetic the Tape on a stick or piece of wire and glue
If you can see it perhaps you can get it loose with a wire or Bicycle spoke or so

I would be nervous leaving it there ....some chemical and patience gets them loose

Thinking use ejector force via compressed air

 

[DogBunny]

Thanks for the suggestions. It's not as easy as you'd think.
The pieces are oriented pointing directly at the spark plug hole. If they were rotated 180 degrees (at the far side from the spark plug hole, where I'd have a straight path to it), I'm sure I would have removed them by now. As it is, you have to insert tools into the spark plug hole, and then immediately curve them straight down and outboard a little. I've been trying to scrape along the piston top/cylinder wall junction with a piece of wire, and I can't even touch/dislodge it.

The large piece I removed was done with grease on a stick.

They are spark plug threads from the aluminum cylinder head, so non-magnetic.

The reason I haven't tried compressed air is for fear of blowing all that crud on top of the piston between the piston and the cylinder wall. Or getting it all over the valves and valve seats. But since the last three posts suggest it, I'll give it a try. Going to take a break for now, and then I'll first give one last try with a piece of wire to see if I can move it to a better position.

BTW -- you'd think that necking down a shop vac to a 1/4" I.D. hose would result in unbelievable suction. You'd be wrong. The suction is surprisingly weak. Blame physics.

 

[zrx1100]

How about bending a magnetic pencil and reaching in there

 

[Jim]

The reason I haven't tried compressed air is for fear of blowing all that crud on top of the piston between the piston and the cylinder wall.

That crud is likely carbon buildup. Once it's broke loose, it'll start to crumble. Any of it that get's down 'tween the wall and the piston won't hurt anything. Soon as you run the engine it'll get burnt/blown out.

 

[DogBunny]

After giving up trying to retrieve this piece of spark plug hole thread with the various tools that I made, I dislodged it with a quick blast of air.


Resulting in this: it's now stuck to the cylinder wall. I still couldn't get to it.


I found this diagram which gave me a better idea of how the wire retrieval tool should be bent.


The "x" shows where the debris piece is. Pretty much the worst possible place.
I finally got smart and found an old, detached cylinder head, so that I could exactly model the bend needed in a wire tool to reach the debris. This worked, sort of. I discovered that my earlier tools were not even coming anywhere close to reaching that piece of thread. I had spent probably 4 hours just futilely spinning my wheels and accomplishing nothing.

So, I did finally reach that piece of metal, but I couldn't get it out. I dislodged it, but then could no longer see it anywhere using the bore scope.


Time for the nuclear option. Of the many aerosol solvents that I could spray into the cylinder, I chose this, and I'm standing by this choice. Basically, it is a thin combination of light oils and non-harsh solvents. It is specified for use inside engines and inside cylinders, and can even be used as an engine fogger.
I sprayed it through the spark plug hole and open valves, using a straight extension tube and one with a hooked end, so that I could blast all surfaces. Then I flushed with a 100 PSI blow gun. Repeated several times, using over 1/2 of the 12oz. can of Sea Foam.
It was a mess, but the results were excellent, beyond my expectations. During clean-up of the work area I found a couple of large pieces of thread. Bore scope images looked great. Even after basting with air, a protective film of oil is left behind.
If you find yourself in a similar situation, I highly recommend this. Do this first, and be done with it. I could have saved myself half a day if I had gone straight to this.

 

[gggGary]

BTW -- you'd think that necking down a shop vac to a 1/4" I.D. hose would result in unbelievable suction. You'd be wrong. The suction is surprisingly weak. Blame physics.

You can get a lot of velocity/volume through a short restriction (orifice) but try to do it through several inches of small ID hose, friction kills the velocity, and you are left with a feeble flow rate.

 

[DogBunny]

https://www.amazon.com/dp/B0CZKVWF4B?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
This is the bore scope I bought. There were a bunch of identical choices on Amazon, this was the cheapest. Has a front-facing camera and light, and a side camera and light. Takes pictures and videos. Not perfect, but an amazing tool for only $15 to my door.

I spent a couple of hours trying to get it to work. I finally came to the conclusion that my ancient phone (a very low-end phone released in 2020), was not up to the task. Bought a current phone that was on sale from my carrier, Consumer Cellular for less than $200. I finally have a decent phone that does all the things that everyone else's phone does.

 

[DogBunny]

Back to the crack in the rear fender...


Applied compression to the fender to keep the crack closed, and repaired/reinforced with 10 layers of fibergalss, visible at the inside top of the picture.


The repair from the outside. Turns out this crack is in a place where it will be way more visible than I initially thought.


My solution. Honestly, not all that bad-looking, and hardly noticeable from a few feet away. Will be interesting to see how it holds up in the Texas sun. I could have gone crazy and tried to level the crack with body filler before applying the tape, but I thought the amount of improvement would not justify the time spent.


https://www.oreillyauto.com/detail/...-5-foot-chrome-brite-striping-tape/trm5/t1818
An interesting product. Looks exactly like chrome. According to AI it's actually aluminum foil. Completely non-stretchable, so it will not conform to compound/complex curves.

 

[Jim]

Be interesting to see how it holds up.

 

[gggGary]

$5 on 300 miles....

 

[DogBunny]

Be interesting to see how it holds up.

I assume you mean the tape, and not the fiberglass. I feel like the fiberglass is stronger than the fender.

$5 on 300 miles....

I'll take that bet.


Here it is in place, bottom center, behind the hoop.

 

[Wagner73]

I assume you mean the tape, and not the fiberglass. I feel like the fiberglass is stronger than the fender.

I'll take that bet.

View attachment 372810
Here it is in place, bottom center, behind the hoop.

Not bad at all!!

 

[GLJ]

Did you drill a hole at the end of the crack?

 

[DogBunny]

Did you drill a hole at the end of the crack?

Yes, you can see it in the 3rd pic in post #50. It is filled in with fiberglass from the back side.

 

[Mailman]

Good looking repair!
I’ll bet that fiberglass will hold up well. On my old BMW, both fenders were solid fiberglass. The only downside to fiberglass was that they don’t dent, they break if they get hit.

 

[DogBunny]

More rear fender damage. The large hole on the left is for the seat stay (the "grab hoop"). They are always wallowed out.
The small hole on the right with the cracks is the upper taillight mount hole.
(The hole in the middle is for the taillight wiring harness.)


Made a repair for the seat stay inspired by this post from Gary:
https://www.xs650.com/threads/home-market-tx650-going-to-soir.66443/page-4#post-844552
Only I don't weld, and I was in the middle of glass work, so this will be a fiberglass repair.
Found the perfect flanged collar, just needed to be shortened.


Flanged collar in place.
Also, using a fender washer to repair the cracked taillight mount hole.


Repaired, I just need to drill the fiberglass out of the holes.
The brown color under the glass is putty that I made by adding flocking to resin, in order to level the surfaces so the glass mat would lay flat.
There are about 10 layers of alternating-orientation glass mat.
BTW, you will note the large fiberglassed areas above and below. The one below is my previously described large crack repair. The one above is a preemptive repair -- it looked like a similar crack on that side was imminent.


The fender stay appears to have been re-chromed, but no one ever bothered to chase the threads on the mounting post afterwards. Instead, they just jammed an SAE nut on.
A great many parts on this bike have been re-chromed, and it's held up very well.
Sort-of-rant: the whole rear fender and seat stay scheme is by far the weakest design point of the early bikes, in my opinion. That single M6 stud in the pic supports most of the fender, and all of the taillight assembly, which is cantilevered out from that stud. The mounting system on the other (front) end of the rear fender is janky and somewhat ridiculous.
It's no wonder that those stay mount holes in the fender are always damaged, and that the fender often has cracks.


Chased the stud threads.
Because of the build-up from the flanged collar that I glassed into the fender, I now need a slightly longer post and stud. Accomplished both at once by taking an M6 coupling nut (left), and grinding a section of the points off (middle).


Here's what it looks like in action.


Left: collection of damaged dampers that slide over that post, and one in the foreground that is still usable.
Middle: gauge mount damper assemblies from 1976-1983 XS650s. One of these dampers usually works pretty well on a slightly worn-out 1970-1973 fender and fender stay set-up.
Right: but neither would work for me. I built-up a damper using a piece of tubing and two inner tube rubber washers.


Here's the final part set. The length of the coupling nut has been trimmed down. Compare to the parts diagram, and the only thing that's missing is the lock washer, part # 19. It's diameter was too great to fit inside the damper tube. I used Loctite instead.

I am very satisfied. The fender is very securely mounted, yet still has vibration dampening.

 

[Its been a long time]

Very interesting. Clearly, the Yamaha engineers were still learning how to build a 650cc four stroke parallel twin motorcycle at this stage in history. Previously, the largest motorcycle they had built was a 350cc two stroke. The engineering challenges are worlds apart, and it shows?

 

[DogBunny]

Very interesting. Clearly, the Yamaha engineers were still learning how to build a 650cc four stroke parallel twin motorcycle at this stage in history. Previously, the largest motorcycle they had built was a 350cc two stroke. The engineering challenges are worlds apart, and it shows?

Honestly, it's a crazy scheme. The R5 (350cc precurser to the RD350), which also debuted in 1970, has a rear fender that makes sense. I don't think there is any other motorcycle in the world, any brand, any year, that has an as-poorly designed rear fender mounting as the 70-73 650s.