the back gear drive shaft

[mudboots]

As I had a knock in my mk1 motor and with a broken wrist which is mending I have pulled my motor apart and have found out why I had no 6th gear it has spun on the shaft and worn it down so my back gear drive shaft is F....d I have the gear box for a mk2 back in Australia and am getting a mate to send me the back shaft gears and all. I have had a look at gearing in FAQ but am unsure if I can just replace my shaft just the back one ? Thanks for any help on that.
+ my crank rod has about 2+ mm play if you move it side to side hanging on to the small end and I think maybe just a tinny bit of play on the bottom big end bearing and for sure the top end baring is sloppy as poo whether a new baring will fix that or is it time for a new crank rod and god knows its not going to be a easy thing to get done here in Thailand.
thanks for any info because if I need the front gear shaft as well to make the back mk2 one work I need to know fast before my mate sends the back one.

[gregorious77]

side to side on the rod is OK up and down is not.

[mudboots]

Sorry what do you mean by up and down ? from what I could work out from FAQ its the front gear shaft to the clutch that is smaller the back drive shaft ?

[knackeredMk1]

Up and down means if you can feel any movement at 90 degrees to the crank. Best done pulling on the con rod when you have taken the top end off and the crank is still in the cases.

Going to do a piece about the clutch shafts but need to wait until I can get my thoughts together and better explain ............. See 2nd last post if you are in a hurry for part explanation - viewtopic.php?f=14&t=3484&start=80

[mudboots]

Thanks for that Knackerded Let me put it this way if I was to leave the clutch shaft as it is and just put in the mk2 back drive shaft gears and all would it fit ?
And as the crank up and down its hard to tell if any but it sort of sounds like the baring might be on its way out.

[mudboots]

Okay just re reading what you have said I do not think the shaft gears will fit and there's no way to get the work done here to make them work so it looks like I will have to buy another mk1 motor for parts or just part my bike out and buy another bike and its not easy buying a good bike here in Thailand.

[Hallsy]

I have a mk1 engine that I have stripped for parts, gearbox looks to be in good condition, but shipping to Thailand would likely be too expensive to make it worthwhile?

[knackeredMk1]

Hallsy's gear set provides you the easiest and quickest option.

[mudboots]

I have a mk1 engine that I have stripped for parts, gearbox looks to be in good condition, but shipping to Thailand would likely be too expensive to make it worthwhile?

Yes that would be wonderful thanks Hallsy The back drive shaft with all it's gear please.
What ever price you feel is right and the cost of posting airmail if that's okay with you if it is I will give you my email or phone number for I can give you the address and you can give me the best way to get the money to you I do have paypal but not sure how to do person to person with it or a bank transfer what ever you like Hallsy.

Cheers Brad.

[Hallsy]

Hi Brad - I will PM you, if you definitely want them I will take them off of ebay.

[mudboots]

How stupid am I I already have a mk2 back gear shaft in or out at this point so it do's fit so now I am confused?
So thanks Hallsy I might get my mate to ship over my other back shaft from the mk2 and see how things fit together first before buying yet more parts. thank you very much for the offer and if things do not work out and it looks like I need to go back to a mk1 back shaft and you still have the parts I will then get them off you,
Cheers brad

[knackeredMk1]

OK full explanation now needed -

I fitted a Mk2/3 drive shaft to my Mk1. The clutch shaft from a Mk2/3 will not fit as this uses a different bearing size from the Mk1. I had to swap some gears around and ended up with some Mk1 gears and some MK3 gears as can be seen elsewhere on the site. I also had to 0.5mm off one of the diameters on the drive shaft and take 1mm (as I remember) off the thickness of the gear from the clutch shaft that was the closest to the clutch. I might also have changed the primary drive gear. In other words it is quite a hassle and took several goes at putting the engine back together to get it working correctly. Easiest thing to do would be to take it back to the original Mk1 gears and shafts. The loss of your 6th gear maybe something to do with an incompatibility of your setup.

[mudboots]

You well are probably right knackered would I have to get a new front sprocket ? it sort of looks like the big washer that holds the front sprocket on a mk1 fits in to it some how for that mater can you even still get them ?
Its just I am trying to keep costs down I have retired now .

[knackeredMk1]

The sprockets are the same. You need a bolt and a dished washer to hold it on but these are still available from Honda. Put some Loctite on the bolt thread as they can come loose. Other way is to machine the spline so that the sprocket holder on the other Mks will fit. Doesn't need to be that accurate as it is basically a slot.