Tinkicker- Thank you for going back and documenting the "trials and tribulations" of your DT175MX journey...  many of us can relate...  and I enjoy your writing style. 

Cylinder sent away for rebore and required gaskets, seals and crank bearings on order, along with the proper JIS screws to rid the bike of the cheap ebay hardware cap head screws he had used.
I spent £100s on genuine yamaha screws, nuts, bolts and small parts over the rehash of this "restoration". A necessary evil if one's goal is to make it as it left the factory.

It was time to pull the rear damper. Another teeth clencher.

To remove the rear damper, one has to remove the swingarm. No big deal, maybe 10 minutes work. Remove wheel, pull the swing arm pivot bolt and pull the lower damper pin.
At least I was not about to be struggling with a seized in pivot bolt. I had come across two badly neglected TY175s in my previous life as a motorcycle techie with seized solid pivot bolts. Took hours with an acetylene torch to get them out.

So with light heart, work commenced. Chain split, wheel out, pivot bolt loose and moving we turn our attention to the damper pin. Sidecutters in hand I prepared to do battle with the split pin.

What the hell....

There was no split pin securing the damper pin in place.

This is stuff that can get someone killed. The pin would have worked its way out in very short order and collapsed the suspension.

I pulled the pin and the remnant was still in the hole. Obviously the split pin had been very stubborn and he had drifted the damper pin out with a drift to shear off the split pin ears.
No problem, I have resorted to that many times in the past, but then I always drill the remnant out of the hole in preparation for a new pin.

Either he forgot to fit a new pin or he found he could not fit a new one because he failed to drill the old one and left it. I hope it is the former.

Either way I resolved that the bike needed to come down right down. I no longer had any faith whatsoever in this " motor industry professionals" workmanship.


Swingarm and damper pulled, I turned my attention to the swingarm pivot inner and outer bushes. Oh my word...

He had not removed the bushes, that was obvious because the were seized solid onto the inner tube bush. The entire slip plane of the pivot was between the outer of the bushes themselves and the swingarm itself. They were loose in the swingarm bush locations.
Not only that, but the bush side thrust flanges were cracked with parts of them missing. Another dangerous fault.

If any of my motorcycle techies in a previous life had shown such gross neglect, I would have shown them the door immediately for gross misconduct.

The pile of bits is growing as like peeling an onion, every level removed reveals more feckwittery underneath.


Bushes seized solid onto inner tube and rotating on swingarm itself and with sideflanges cracked and parts of them missing. In what level of hell would they ever be considered roadworthy?
Lower damper pin still blocked by old split pin. Not a dab of grease used in the reassembly.

You are losing it.

Helpful.  Thanks for your input Cliff. 
​​​​

Seized swing arm spindles, on a TY175, can be removed using a 1mm cutting disc in less than 10 minutes.

Just cut through each end of the spindle, push out the spindle and sleeve It's rusted into, and replace with new parts.

I make stainless spindles for them, which helps lessen the chances of problems in future.

That method will work on pretty much any bike, with a seized spindle, and if it's not possible to get a cutting disc in, an air hacksaw works very well.

The replacement swingarm outer bushes, inner tube bush, cap seals and cap seals for the the damper pin arrived in the post along with a bag of genuine hardware from CMSNL; and I was able to start putting the back end back together.  Next day the replacement shock arrived.
​​​​​​Swapped the cap shims over into the new cap seals and started to put it back together without incident and with two more parts than before... A washer and split pin.  Maybe four.......
Can I call moly grease and copperslip a part?

Looking much better, the rear shock looked pretty much as new, although I would guess it was the later 1980 model. Double checked the part numbers and the 78/79 style shock part number was superceded by the 1980 style.  So all good.


Far safer rear end. At this point I am trying not to see the wiring.

Check the shock bump stop rubber. Most have disintegrated by now, and if you use the bike without one, the shock will be damaged.

Is it me, or do you enjoy stating the bleedin obvious after the fact?

I have a new forum name for you - Needle.  

Its very easy to miss destroyed neoprene foam bump stop rubbers. They often appear to be perfect, and crumble as soon as shock is fully compressed. I found that out on a TY Mono I have.

Never seen a road bike ignition with high and low speed source coils, and if your running problems occur over a certain RPM, may well have to do with that?

Try calling Steve at Bradford Ignition Services, and outlining your problems.

So swingarm refitted and all the new brightwork fitted.  All the snail cams, levers ect had just been painted previously.  
Those Cheapo VRubber tyres will have to go, completely wrong tread pattern.  Absolutely hate them.  Have crossed paths with those before, horrible to mount, stupid tight beads, hard compound and six ply makes them real finger trappers.

Kenda do some in the correct size and pattern, a far better tyre.
(I still have those VRubs lurking in the shed somewhere.  If you want a pair of free, 1 mile old tyres, just jump in the car to collect and they are yours).



Other side.  That brake rod offends me, it has been painted black and new ones unavailable ( at time photo was taken).  The correct finish should be BZP.
The wheel spacer was also unavailable, but after months of inputting the part number into ebay daily, one came up NOS.
Competition was fierce, but I ended getting it for £20 and a few pennies.
The old one had been painted silver and was very very badly pitted.