Special radius bearings like the one Yamaha used have been available from sources other than Yamaha. I've purchased them from a bearing supply house near where I used to live.  It was a standard stocked product in their warehouse at least several years ago.  The counter guy told me they were common in power transmission products like transmissions and gearboxes.  I remember them as "2RS" versions from the bearing supply but the seals pop right out.  

In fact, sometimes Yamaha has "superseded" the correct bearing with a standard incorrect one. 

Its not a problem. I will just ask the lads in the machine shop to grind a new fillet on the new bearing to match the old bearing if required.
Believe original is 3mm and standard is 2mm.  Jason, the shop foreman has such a keen eye and steady hand, he probably will not even bother setting up the grinding machine.  I have seen him do it before by hand on the big pedestal grinder.
It will cost me a packet of jaffa cakes.

Rod kit arrived and I will press the crank back together on monday. It came with a new small end bearing, so I do not have to open the new genuine one. It is the correct, wide shouldered one for the 175.

Piston arrived and is identical in every respect to the old one.

The corrosion pitting on the left shaft has been sealed with loctite shaft repair goop and sanded down to a polished surface. It is no good for running seal lips over, but will ensure the new seal does not get torn on any sharp edges on refitting. The inner lip is well clear of any pitting, which was confined to around the dust seal area.

I ordered the last remaining ballrace in the transmission. 6303z. Felt fine, but for the sake of a fiver, I will replace it. I know that the two needle rollers are in perfect condition and have never corroded as I can see the running surfaces clearly.

So things should start happening next week.

Crank rebuilt and trued without incident.  Well apart from the last millimeter or so when the pin creaked and jumped.
Luckily I already had my feeler gauge in place so it stopped it jumping too far.

It got a sodding good grip on it though.  A moment of consternation when I thought it was stuck solid.  A good clout with the copper freed it though.

Crank trued up easier than I ever had before. Initial set up with square brought 0.05mm.  A tap with a wedge between the flywheels brought it down to 0.01mm.  About time it cut me a bit of slack.

0.01mm runout.  Well within factory tolerance and at the limit of the gauge resolution.  Happy with that.


Other end.  Width turned out to be 55.94mm.  Close enough to 56mm for me.  Esp considering it was a bit chilly in there this morning.

Quick heads up on output bearing.  Comparing 6304 NR and original bearing together, the 6304NR CAN NOT be made to fit.

6304NR has a filleted inner bore.  6304NXT has a straight shouldered inner bore.  Otherwise identical.

Whatever butts against it is around 25mm dia judging by witness marks and outer edge of NR fillet is 24mm.  Too close for comfort.

Genuine bearing ordered.  

Couple of hours to spare this morning.  Cracked on building the bottom end.
Left case heated to 100C and crank dropped in.  Transmission dropped in next, giving that expensive special output bearing one last glare before left case fitted. 
Even tried the stores manager who orders 100s of bearings a week to see if he had seen a bearing with the same number.  Nope. Out with the bearing books and nothing.   Arm and a leg time..

Cases screwed together, tried the gears and I have a box containing six gears that snick in and out.

Fitted new piston with new small end, new circlips but original rings and pin.  A word of caution when cleaning out a bottom end after a holy piston event.  Even the piston pin had debris down inside its bore.

Bottom end complete.  I will fit the top end tomorrow and leave the outer cases until after the motor is in the frame.

Still need to strip carb, subject it and the intake parts to a warm bath in my ultrasound machine.  Rebuild with genuine std main jet and throw the damnable spurious ebay special one as far as I can over the garden wall into the field behind the house.

Bottom end built.


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Impresive stuff ya doing there Tinkicker & keeping us informed.
Keep up the good work.

A couple of hours spare this morning so I thought to build the top end of the motor and stick the carb top parts in my new ultrasonic.
Did the bottom end of the carb yesterday and also rebuilt that this morning.
My old machine was little more than a jewelry cleaner that I used for cleaning watch movement parts.  Carbs were left partially uncovered and needed turning regularly.
New one has plenty enough capacity to dunk carbs easily, even though it is only 3 litre.  It, being the more powerful pro model also has 4x the power of the old one.

Waiting for the machine to reach its set temp.  While waiting I built the top end and carb body.  I was not going to do the cap, but I just wanted to have another play with the machine before tossing out the cleaning fluid.



The offending item.  That ebay special jet cost a fiver.  The genuine one from Fowlers cost fifteen quid.  I thought a 130 jet was a 130 jet, was a 130 jet and gave it little thought.  A tenner saved is a lot.
That tenner saving cost me well over a hundred quid to put right the damage that jet caused.
If you take anything from this thread, it is do not skimp on carb jets.  It may well bite you on the ass.


Also got the engine in the frame and the right side of the motor built up.  She has strong compression at the kickstart.  A bit more insurance..that plug is a B9ES. I went for a step cooler since the bike will be ridden pretty much wide open most of the time.  Rural roads, little traffic and 60mph limits round these parts.  I read somewhere that the B8ES is borderline  hot for open highway use.


Sprocket and chain refitted on left side.  Needs carb, left case, exhaust, wiring, tank and seat refitting and she is repaired.
Stomach is growling so I need lunch.  May or may not do a bit more this afternoon.
Also need to remember to bring home the neutral switch from work.  I took it out when warming the cases to drop the new transmission bearings in....and forgot it.






 

TK looking good. I like your ultrasonic cleaner!

Lets hope it is happy now.  Apart from the powdercoat on the frame, I cannot think of anything that has not been attended to since I bought it.  It has not let me get away with anything at all.

It is by any measure, pretty much a brand new bike.  

Your bikes remind me of the cars I see on Barrett-Jackson and Mecum auctions. So clean in every way.