Author Topic: 1978 YZ80E Rebuild  (Read 11040 times)

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Offline 80-85 husky

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Re: 1978 YZ80E Rebuild
« Reply #15 on: January 05, 2019, 09:55:06 am »
good to see the fire is still burning... ;)

Offline huskibul

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Re: 1978 YZ80E Rebuild
« Reply #16 on: January 05, 2019, 10:23:28 am »
Great work as usual alex ! and your spot/on with decal placement nothing looks worse on resto's than stuffed up tank badges -pox ! haha makes you wonder about rest of the bike  ????

Offline alexbrown64

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Re: 1978 YZ80E Rebuild
« Reply #17 on: January 06, 2019, 11:46:38 pm »
Thanks guys...

Well, i couldn't just leave it again in the shed without trying to ride her.
The clutch is activated on the left side by a worm drive arrangement and a rod that goes through to the clutch side.  Some may remember that whenever the chain was dropped, it would bend the rod and you would have no clutch.

Anyway, i found all the bits in boxes and got all that side of it working.. but the clutch plates themselves were seized together.  So, drop the oil, rip the cover off, pull the clutch and clean and soak it all.
Got the clutch all working well... Next stop, find chain, front sprocket, nuts etc.. rebuild a chain tensioner and prepare the bike for launch.

It was getting dark, the kids were getting hungry and i had tools flying around the workshop... this was a mission..

There are no brakes fitted and no footpegs.  I just wanted to see if the tranny, clutch and motor would work.  I fired her up, pulled the clutch in, selected first and took off up the street.  The 78 had a 5 speed box, so in my boardies and Crocs i get her up into 5th on my street as darkness descended.
Never thought i would see this thing running.  But the old Yammies are indistructable, and this one has a smooth gearbox and clutch.  Motor run OK too.

I put her back in the shed with a grin on my face.  This one is now ready to start a full rebuild.



Cheers,


Offline alexbrown64

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Re: 1978 YZ80E Rebuild
« Reply #18 on: March 18, 2019, 06:14:58 pm »
Its been a while, but i have been very busy. Still have all my VMX bikes, but i also now have a 2019 YZ125 and the boy has a 2014 YZ85.. so we go out riding as much as possible and they are both great bikes in their own right.

The E has not been on the backburner.  Ive been tinkering and cursing for quite some time now.  If there was ever a bike that was completely fukced, its this one.  I don't think there is a nut or bolt that's missing, bent, stripped or wrong.
The bike needed a rebore.  Its now 3rd over with a Yamaha nos piston and ring set. I had to get a new nos cylinder head.
The footpeg perch needed replacing, so i found a nos one in Sweden. The brake pads were toast, so for now i pinched the ones from my 80F project.

Believe it or not, there is about 1k in parts in this old banger as it sits in the pics below. Took the pics today.  I have her up to a stage where you could take her out for a ride.  Clutch, brakes, gears, etc.. are all OK.  Forks are shot, but bounce up and down.  I found a 78 YZ80 replacement kickstart and a few other nickers nackers to get her running correctly.  I had to replace the swingarm, as someone had modified the old one to make it sit taller.  The mudguards are original and in OK condition.  I have had to heat them a lot to reshape the twists out of them.

The tank had gone rusty again, so a major clean out with acid, then rinse and neutralize.  Then a coat of oil internally.

I now have a massive inventory of new old stock spare parts for this old girl.  Its a few years off and will be a very slow process getting her back to new condition. If anyone has an original front number plate, then give me a shout...





I also got hold of the original Yamaha YZ80E tech report for the frame and suspension mod due to cracked frames.
I have the kit and have also found a nos stiffer shock spring.  Will be following the report as part of the project.





Cheers,