Last of the Twinshocks '78 DT175

[davecumbria]

Some of you may have seen this restoration blog on a couple of forums thought I'd let the rest of you Yamaha Nuts have a look

Here are pics of the bike as bought, it had stood in a barn since 1992 has 2 owners (brothers) so it's been in the same family since new

1) How the bike was found

2) Rare seat intact!!

3) The bike back home

4) Father Ted Number Plate!

5) Original mileage

The bike was stripped down carefully and salvageable parts identified and sorted for rechroming. The Fuel tank held about a gallon of fuel from the bikes last use, Four Star fuel does not smell nice after fermentation for sixteen years the tank was cleaned and sent down to Custom Painter along with the mudguards and an NOS oil Tank I picked up at Stafford for £20!

6) Chroming sorted out

7)Wheel Rims and Bars

I got some quotes for recroming the rims and Bars, the rims were quoted at £120 each and the bars £50, so in the end I managed to get some new rims for £160 and some Bars for £42 delivered so I've kept them for future use.

At this point I must mention that The Ripper off the forum was unable to do the Chroming due to unfortunate circumstances, so hopefully if these change I'll get him to rechrome the originals

8)The Frame!

As you can see in the original pics the frame was pretty rusty, normally I powdercoat my frames, but I wasn't happy with the results, as they get blasted and powdercoated without any preperation of the frame, so any blemishes are visible in the powdercoat surface. Now I'd done a job for a local bodyshop and asked if they would paint it for me, (a bit too heavy and too far for Custom Painter). It was dropped off this morning, (Christmas Eve)and I'm very pleased with the results!

A massive amount of cleaning is going on at the moment but I'm hoping to get on with reassembly over the Christmas Break........will keep you posted!

So Boxing Day turned out to be a good one for working on the bike, no call outs, no phone in the office ringing (it will start tomorrow!)

Zinc Plating should have been away before Xmas, but the lad who normally does it for me has been off work, but it means that those annoying little bits you forget to put in are now there and waiting to go

9) Tin of bits waiting to be Zinc Plated

Managed to get the Engine Stripped down to check it out, I'd got new Oil Seals but totally forgot to order the bearings, the barrel is still on its original bore, but the rings look a bit thin and there is evidence of "blow past" The bottom of the crank is a bit brown, but I think that old petrol still in the crankcase will have gunged a lot of it up

10) Engine on the bench

To keep the screws in the right position so you don't get the lengths mixed up this is a simple method of keeping them right

11) Crankcase screw template

A Pic of the original piston, I'm hoping that a glazebuster on the barrel and a new piston and rings will mean that a rebore wont be necessary

12) Original Piston

When I took the clutch pressure plate off one of the oil rings was broken away, are these necessary? I think that its about the same size as the RD200 so I've got a spare clutch i'll check the part numbers

13)Clutch Plates

Theres been loads to do, cleaning sanding, painting but its been quite relaxing apart from when you cant find the part that you know was put away safely but this is how far the frame has got on

14) Frame assembly

Note the Genuine NOS Shocks!,

Its been quite suprising what is still available from Yamaha, as we all know RD parts are running low, but I got all of the rubbers, shocks, cables from Granbys.... but I've missed ordering the footpeg rubbers!

[DirtyDT]

Looking like a very good project.

I like pictures.

[davecumbria]

Today I have mostly bin polishin!

15) Hubs

But I did nip down to my favorite little closed down Yamaha Shop to pick up some bits. Its great having a rummage through old boxes of parts and finding things you want.

Found a box of second hand stuff that I'd not seen before, but in a packet at the bottom of the box were these.....

16)Badges

NOS Genuine FS1e Tank Badges, the proper "flat" ones as well!!

Sunday and back to work tomorrow so I've been tidying up but I did get the chance to respoke the front wheel.

So heres the "dark art" of respoking revealed!

I took some pictures of the wheels before cutting the spokes with a bolt cutter (easier than a grinder)

18) Original Rim

There are two types of spoke inner and outers

19)Inner Spoke

The inner spokes are installed first, threaded from the outside of the hub, you can refer to the marks on the hob from the old outer spokes, or the picture, every other hole on each side for the inners.

The tricky bit onece the spokes are threaded is to get the hub flat on a work surface, and then angle the spokes in the direction they are to go (drum plate side swing left) or top side of the hub swings left.

working from the valve hole, every fourth hole to the left for the top spokes, every fourth to the right for the bottom. At some point the rim will require lifting up as the spokes will centre it up.

20) Inner Spokes Fitted

Note the little boxes holding the rim off the worktop

If you carefully screw each spoke nipple to roughly the same length up the thread, it will make things easier to allign up

Next the outer spokes

21)Outer Spoke

each side can be done seperately, threaded from the inside of the hub outwards

22) Drum Side Outer Spokes

Outer spokes swing to the Right so every fouth hole again

23)L/H outer spokes

These again swing to the right, every fourth hole unless you've mucked up

The finished article ready for trueing up

24) Front wheel

So whilst the above was in progress the fork bottoms were baking away quite nicely

25) Fork Bottoms

They weren't in too bad a condition apart from the usual problem of the Alloy oxidisation, I'm trying to make the bike "as manufactured" so I resisted the temptation to polish them up. The remaining laquer was removed with Nitromors and the legs sanded using a worn 400 grade emery paper wrapped around the fork leg to give that "brushed" finish. If anyone remembers Yamaha didnt brush all of the leg, the ears and the bottoms were just painted ith a silver paint, so this has been reproduced in the effort to make them look NOS.

Please note the alternative function of the Oven in the Kitchen

26) Fork Legs

The forks were stripped during the bikes dismantling, and had been sent to Philpotts for rechrome, again I can vouch for the service and turnaround

The seat was still fitted to the bike when I picked it up

2) Rare Seat intact

The rear dampers were missing and curiously were found with the tabs split off in the innards of the mudguard when I stripped the bike. The two rear support brackets were bent down into the seat base so I'm surmising a bit of heavy two up activity was going on at some time.

The remaining dampers, hinges and strap were unbolted, and the bolts chucked into the Zincing tin.
With the help of an angle grinder with a brass brush fitted, the base was cleaned and 3 coats of Smoothrite applied (those brass brushes and an angle grinder cannot discriminate between soft finger ends and metal)

31) Seat Base

The edging strip has been refitted and the tangs carefully eased out to facilitate the fitting of the original cover

The original cover was cleaned with some Valay Vinyl cleaner, the product was so old it gave instructions how to clean a Vinyl Roof on a Car which reminds me I must order a new one for the Capri ;D

32)base of seat recovered

The cover looks pretty good considering its age the picture of it shows it after cleaning, with no polish used!

33) Seat recovered

[davecumbria]

As the fork bottoms were relaquered, the old seals were removed by carefully cutting them with a dremel and levering them out (nervously! should have done that before they were stripped and relaquered)

Anyway, came up against that usual problem of how do you lock the damper to tighten the Allen Screw in through the bottom....

Desperation is the mother of invention, so I got the handle off the Trolley Jack and cut a slot about 10mm down from the end at each side of the tube

27) special tool 1

the end of the tube was then squeezed in the vice and ground to shape

28)special tool 2

Dual purpose Trolley Jack Handle!

So the fork legs are completed and looking good

29) Fork Legs

only real problem was that as I cleaned up the lower clamp I noticed the Crack running right across it

30) Lower Clamp

Delivery today from Granbys,

so thought I'd better get on with something that I'd been a bit nervous about, the rear wheel

As with the fromt wheel there are inner and outer spokes, but to complicate matters, the Inners are two different lengths and the Outers are also different, so Four different spokes to wrestle with

34) Inner Spokes

It was only after about half an hour wondering why it wouldn't lineup properly and removing the inner spokes I realised I'd got two mixed up, so after a few choice expletives....

35) Inner Spokes Fitted

So as with the front wheel, one side at a time is laced in checking the spokes are the same and the correct side of the wheel

35) Outer Sprocket side fitted

36 The finished Article

The engine rebuild is the next stage.... but the casings were pretty badly oxidised with the damp where the bike had been stored, in order to try to keep costs at a reasonable level I adopted the technique that I'd used on the my RD250F cases.

Alloy wheel cleaner (which is a mild acid) was brushed on to the cases and left to soak before washing off, then using a brass brush in a dremel the casings were cleaned off and polished up.

The techniqe at the eary stages of the process is to keep the casings wet so the soft brass brushes dont wear away too quickly, then once att the oxidisation is removed a dry brass brush can be used to polish the alloy, I've used an assortment of brushes to get into corners, and although the cases look quite highly polished, after a few days they dulll down to a more acceptable "original" finish

37) Action Photo!

Picture showing the left hand casing with the new finish against the original right hand.....notice all the excess Yamabond from the factory!

38) Left case cleaned

During the clean up and removal of all the crud and grease around the front sprocket, evidence of damage to the cases was discovered, probably from a chain flying off, its chipped the clutch actuator housing, so some alloy welding will be required I think

39) Casing Damage

But I cleaned up the casing anyway, I dont think the damage is bad enough to require replacement

40) The finished Cases

Once the engine is rebuilt Solvol will be used to remove any obvious brush marks.

A couple of hours work on a cold sunday morning saved vapour blasting and postage costs so worthwhile I think....more to follow!

[blackhat250]

Its a great read dave, ,, lovely colour the 1G1 model , Our Usa cousins will not have seen them colours,

[davecumbria]

Stop Press, Zinc Plating is done, many thanks Kev! Collected it tonight and its very bling! Sorted through the big tin identifying parts.

41) Zinc Plating

Theres a bit of RD stuff amongst it as I'd missed them out of the last batch.

So as you do, couldnt wait to start, so fitted the original cup headed bolts to the seat brackets, strap and latch

42) Completed Seat

And the newly painted exhaust was dry!

43) Exhaust

The bad news is when reassembling the clutch I checked the plates, and they are cooked, so another order off to Granbys

Anyway, decided to have a go at the outer cases, some restorers polish the cases to a mirror finish, but I like to try to make bikes "as manufactured".

The sprocket cover was badly damaged, and it looked like the oil pump cover had hit a rock at some stage so both were unuseable. The Clutch cover had badly oxidised, but as they are like hens teeth and expensive (I found a clutch cover in the USA but it was $145, so with the £ doing a nosedive, and having to pay customs and VAT it would have worked out at over £150!!

So, stripped what was left of the laquer with Nitromors, sanded the cover, then polished it up. The covers were lightly sanded in the attempt to copy the original "brushed" finish, but in the end it was a fine steel brush in the faithful Dremel which came to the rescue.....

What do you think?

44) Clutch Cover

45) Generator & Sprocket Covers

I know its been a while, but things have been ticking over, parts have been arriving from Granbys,its amazing the stuff thats still available for these bikes I'm sort of used to the empty shelves where RD parts once sat.

But tomorrow I'm off to pick up the Paint Set, courtesy of our fave paint man Custom Painter

Looks fantastic, cant wait to get it on the bike!! more pics soon!

The paint job can make or break a restoration project, and so of course the tinware was sent down to Tony Collins AKA Sleazy Rider AKA Custom Painter

This design of DT Tank is the hardest work of all the range as the graphic is a single panel on the side of the tank I know that Tony had a problem with the graphic, but it was sorted out, and when I got the Tank home I had to fit it

A bit of Autoglym and it glows!!

So started refitting the engine cables mudguards etc, waiting on a few things to come back from the Chromers hopefully the front wheel will be fitted tomorrow!

There is still quite a bit to do, the handlebars are temporary ones as I havent been able to get a correct set, and the speedo and rev counters have been dismantled to get the original cases rechromed.

All of the cables are new mainly beacuse the old ones were badly corroded and re-using old cables is not the safest thing to do.

So a steady Saturday Afternoon working on the bike

Things have stood a while waiting for jobs to be done.

When I bought the bike as a project I was reasonably confident that the bore would be good as the bike had only covered 3800 miles....

how wrong can you be! I managed to get hold of a standard piston (genuine) for the bike and when I tried it in the so I thought, standard bore it would have gone in crossways! so the bore was honed and measured 67.13mm! (standard bore is 65.96 so 4th over is 67)

which meant the barrel was useless.

So I contacted a company called Jetbore down in Wolverhampton and for £105 inc postage, the barrel was re-sleeved, the job took slightly longer than expected but (quoted 10 working days) after 3 weeks the barrel was returned with a new liner installed

49) Re-sleeved barrel

so after a good clean up to ensure no swarf was remaining in the transfer ports a couple of coats of PJ1 and off into the Oven!

50) Barrel Cooking nicely

The oven is really handy because after about 1hr cooking (with the door open) the paint was hard enough to claen of the fins with a Dremel

51) Finished Barrel

So the vibration rubbers were fitted and it was re-united with the Cylinder head, which I'd prepared earlier

52) Head and Barrel

I had seen a tip in Tansha magazine where you fit one gudgeon pin circlip and fit the piston in the barrel past the rings, before carefully lowering it on to the block before pushing in the gudgeon pin and fitting the final circlip into place (with a cloth in the top of the crankcase) then lowering the barrel down into place

IT WORKS!!!!

53) Barrel and Head Fitted

So now the exhaust, carburettor and tailpipe can be fitted hopefully for the final time

I've managed to pick up the correct rear indicators for the bike I had mistakenly purchased earlier versions, which means I'll probably sell them on (they are the same as RD250/400 so I guess there will be a market for them!

54)Rear end

The number plate is the original one which came with the bike and although it has a scratch on it, it has the original dealer logo on it so it will keep the bikes character.

55)Motor completed

There are still some things to do, I've had the NOS rear sprocket Zinced as thats what they had on when new, and I suppose a chain would be handy, the Items I've had rechromed wont be ready until next week so the handlebars are temporary.

I managed to get a 350 rear tyre with a classic patten (modern tyres are 400 and they look odd) so when I ordered a Pirelli classic Trail tyre for the front by good luck its a perfect match for the rear.

56) Nearly there

And now here is a bit of a Problem..........

cant get it out of the Kitchen,

[davecumbria]

Well the final part required for the bike arrived today, courtesy of Peter Spicer. The front Mudguard Stay had disintegrated in the chroming Vat, and so Peter Very kindly let me have the part until I can get another one

So some Before and After Pics

Before

After

Before

After

And a few more for luck

oh..... and a final footnote, this afternoon I took the bike down to the original supplying dealers, the chap there had asked me to "loan" the bike to go back into the shop where it had languished for many years after being rescued form a barn.

Dick and Pat have become friends over the last few months as they have followed progress and helped as much as they can, here a a few pics of today

Dick Harrison, the original dealer who supplied the bike

He can chat for hours about Yamaha's (they used to race TZ's)

The original Dealer Sticker now proudly re-installed on the side panel as it would have been when new (He's still got them!)

Back into the shop where the bike was originally sold out of, the shop closed in 1983, but due to the couple living over, its not been practical to do anything with it

There are still stickers and peg boards on the walls, the place still holds memories for me as I used to get bits for my bikes from there in the 70's....it still has that aroma which can trigger thoughts of times long gone!

[Airhead]

First class Dave what a stunning restoration af a fantastic little DT twinshock...it couldnt be bettered

[nayruf]

Hi

I am lazy my first twin shock was in 78 the same colour as your restoration, I am now many years later on my second one a red stripe one, Please can you come and work your magic on this one for me, hehe, also I am now gonna crack test the lower fork axle clamp for cracks.

[Sacha]

Very nice! What a beautiful bike. And love the father Ted license plate... I'd have kept it on that fact alone.

Oh, and that's got to be the cleanest oven I've ever seen!

[jimmy]

Dave

That is a FEC'ing lovely bike, well done mate

[Noise]

Wow what a cracking restoration, and its always nice to get some history with it as well. pat on the back for you good sir

[UK_DT]

Superb restoration, great set of photos and a really good description of what you did.

Thanks for sharing. It's given me the inspiration to get the few bits I need to do to my 400 before I ride it again during our long hot summer (I sure that's what they're predicting!!)

[bazza b]

really enjoyed reading about your restoration

what a nice job

gota go

start work on mine !!!

cheers

[vayduh]

Amazing level of dedication to getting it right. Love it.

[Lenmac]

I am in the process of rebuilding exactly the same model an I wondered how you got the the speedo and rev counter re chromed as they don’t appear to come apart?

will they do it with the insides still in place?

[Airhead]

last time he was on here was 2018 Lenmac

[Lenmac]

18 hours ago, Airhead said:

last time he was on here was 2018 Lenmac

 

Ok thanks for that.

[Snakebite68]

On 4/11/2013 at 9:09 PM, davecumbria said:

the speedo and rev counters have been dismantled to get the original cases rechromed.

They obviously do come apart, since he got his re-chromed...

On 2/2/2022 at 3:35 PM, Lenmac said:

I am in the process of rebuilding exactly the same model an I wondered how you got the the speedo and rev counter re chromed as they don’t appear to come apart?

will they do it with the insides still in place?