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Posted

As well as being my daily transport this is also a running project! It has its ups and downs...

When its behaving itself it looks something like this:

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But following a spectacular main bearing failure I'm now in the process of rebuilding the 2A8 engine...

Took a few minutes to remove the engine from the bike and get it on the bench.

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Does anyone know where I can source the correct right hand main bearing with the groove in it for the retaining clip??? 6304NX2 I seem to recall...

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  • Moderator
Posted

Google Ty trials.

You will get every single part you need from them.

Rebuilt mine twice with parts from them and have no complaints on price or service.

  • Like 1
Posted

Any decent bearing supplier should have/get you one

I've already got my local bearing supplier on this and they're looking into it for me, thought I'd ask anyway. :)

Google Ty trials.

You will get every single part you need from them.

Rebuilt mine twice with parts from them and have no complaints on price or service.

Just looked them up, found a few parts I require that I haven't found anywhere else! Cheers!

Right then, after dissassembly... the left hand main bearing does not want to part from the crankshaft. Took it to my friendly engineering shop and got them to remove it.

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Water keeps getting into my gearbox and I think I've finally found out how! Note, gearbox oil should not be this colour!!! O_o

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Found how its getting in me thinks... Its going to be a pain to remove, look at those corroded heads!

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And check this out... crankshaft oil seal not sitting correctly. Oh dear...

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Posted

Eck. Ive done this in 2014. Pushed impact driver with BRAND NEW BIT Into heads. Worked ok for me.

S.

  • Like 1
Posted

Good bit of work going on here, since when did yams start using NX bearings [ grooved] Kawasaki had them on gear shafts. on horizontal split casings. cant see how they"d work on vertical split engines,, :eusa_think:

Posted

Eck. Ive done this in 2014. Pushed impact driver with BRAND NEW BIT Into heads. Worked ok for me.

S.

That'll work for the two heads that are still intact. One of them is almost non existent! Eeek!

Good bit of work going on here, since when did yams start using NX bearings [ grooved] Kawasaki had them on gear shafts. on horizontal split casings. cant see how they"d work on vertical split engines,, :eusa_think:

Who knows! - I'm not Yamaha! ;)

Ta da, picture:

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Posted

I built my H2 a few times , the grooved bearings had a half clip, it was to stop lateral movement, [ so I was told] that another reason you get missed gears,[false neutrals] if theres wear [ even 1 or 2 mm] on bearings the shafts move away from each other enuff to miss gear selection, couple this together with worn selectors and its rebuild box time,

Anyway the mains were normal bearings held from spinning in the cases by a smear of locktight,,

Posted

The new right hand main bearing I was supplied (supplied 6304 not 6304NX2) does not have a groove. I rang up the supplier about said missing groove and after some research they said that all bearings they could/would supply would not have this groove and that I would have to find it elsewhere. Oh well!

  • Moderator
Posted

I've just been on the phone, if you send your old bearing to bridge engineering in Stalybridge they will see if it's the same a 6304NR they arent sure what the prefix NX is

  • Moderator
Posted

Thought only the output shaft bearing had a ring.

Mine dont have one.

  • Moderator
Posted

I can see where the confusion lies, you led us to thinking you ere referring to a crank bearing because you called it a 'main bearing' it's the gearbox output shaft bearing isn't it.

Posted

Yes you are correct! My mistake!!! :madflame:

Just checked the engine casing. Guess which bearing is still sat in the engine case and guess which bearing I removed (and for some reason) assumed I removed the right hand main bearing.

D'oh!!!

Don't I look like a right plank now. :crazy: :crazy: :crazy:

We learn from our mistakes though, don't we?!

  • Moderator
Posted

Shows we know our Dt mx's as well.

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