1979 DT175MX rebuild

[cossackman]

So, thought I'd start a thread for my next project. A 1979 DT175MX.
My brother bought this on a whim from a pal of his. Originally a German spec bike, it was imported here about 10 years ago, used for a short time, then stuck in a draughty garage in a coastal village. Needless to say, it has suffered a bit of corrosion but not too bad.
I was quite surprised to find that the bike is very original, even down to the rubber covers on the axle ends! Also, it only has around 3500 miles on the clock.

[kelvfoozinda]

Engine looks lovely now! and the bike looks pretty complete. Do you know if the motor shares much with the TY?

[cossackman]

All the screws on the motor have now been replaced with stainless ones and the carb drain hoses have been renewed too. Still to swap the two stroke flow and return pipes just for peace of mind.

Not sure about the TY motor. I would imagine the gears could have shorter ratios. The cases are the same as the pre-MX DT and the TY I believe?

Had a right tantrum today when the freshly blasted and primed frame was getting it's first coat of black. Primer and black reacted with each other so it now has to go back to get blasted again because it's a right old mess! Still, no big deal. I've only got to have it finished by Dec 21st!
Fork stanchions off for rechroming, smaller items to get rechromed elsewhere, front wheel to get hub refurbed with new spokes and rim.
Exhaust is mint as is the seat, clocks have a bit of fading on the cases but that should come back with a bit of heat gun treatment. All the consumables like chain, tyres, tubes, sprockets, bulbs, etc are already bought.
Fuel tank is scrap as it's almost rotted out at the back lower corners. Condensation settling during storage probably. Got a replacement that is clean inside with just a slight dent on the side.
I've run the bike up to temp every so often so I know it's a good runner so once the bike is built, I know it'll run.

[cossackman]

So, frame, swingarm etc back from blasters. Strung up for painting along with many parts for the black treatment.











Fork stanchions will be off to Philpotts for chroming. Thankfully, there's not a lot of chrome on this bike so these parts minus the headlight rim (got a UK spec complete headlight now!) will go off to another place.




Bagged a VGC front wheel off Eb*y USA for just under £100. Currently, the build expenses are sitting at just over £700. This is including a zinc plating kit from Gateros Platers at £54 which will be used for plating all the bolts and fasteners. Will post pics of this as I try it out.
Remaining costs will be paint for tank and graphics for tank and sidepanels (£52), a pair of new inner tubes, a couple of indicators, fluids for forks and motor.

More later!

[cossackman]

Frame has now been re-done. Finishing off painting brackets etc. Will start the zinc plating of the nuts, bolts etc sometime this week. Can't start the re-assembly without them!

[twoblackcats]

Proper job on this one then, good stuff.

Great little bikes the 175's well capable in the dirt too. In fact did Yamaha ever make a bad air cooled 2 stroke? Not that I can think of that's for sure.

[cossackman]

I used to have a twin shock DT175 when I was 16. No lights for off road stuff as back then, there was plenty ground round here to play about on. I'd like to get another, maybe to make amends for the abuse I put it through back then!

I think the old air cooled strokers Yamaha made were pretty bulletproof unless daft teenagers started 'tuning' them. Having said that, there was a kid near me that had a Fizzy with serious tuning and a one piece tank seat unit. It was clocked at 80mph! The guy that tuned it also had a PE175 Suzuki that was allegedly clocked at just over 100. Rumour was that it was running Avgas with some porting work done.

Originally, I had planned to sell my DR600 and use the K75S as my daily. Now, I'm steering towards restoring the DR600, sending the motor off to be reconditioned as it's now on 36,000 miles and quite tired while I'd get on with the rest. Had a phase where I was going to strip it down, fit 600 Bandit front end and wheels and turn it into a sorta café racer. Decided against it, instead I'll wait till a more suitable bike turns up for that.

[dodgerover]

Looks a nice little project, is there any chance of a set of tracings from the tank decals so i can make a set up please?
Thanks

[cossackman]

I'll see what I can do for you. I'm just using a set from E*ay (2x tank sides, 2x sidepanel ones) £52. On 9 year vinyl so should be fine.

[cossackman]

Today, I ran the loom through, finding out that, due to the compact route the exhaust takes, the loom has to go in only one way. Even referring back to pics taken on removal, this was a pain!
Hooked up the clocks, lights, controls etc to check the loom although everything worked fine on removal and all is fine.

Next up was the motor. During the stripdown, I noticed the top rear mounting bolt was missing so ordered a new one along with other bits and bobs from CMSNL. Even though it's only a 175cc single, it was still a bit of a faff getting the motor in without scratching the frame. Managed to get it in with very little scratching, hooked up all the wires and plugs (5 in total!) connected up the pipes for the 2T oil.









Finished off painting the bash plate, brakes plates and rear light holder. The headlight is a new item. Hoping to get the exhaust fitted tonight.



Just been looking at the cables. When I put them up against the bike, the throttle, front brake and clutch cables look quite tatty so will order new ones.

As I already have a NOS back wheel, I'll get onto fitting the back tyre, rear brake, chain and sprockets and new snail cam adjusters tomorrow night.

[cossackman]

Oct 2, 2013 9:40:21 GMT dodgerover said:

Looks a nice little project, is there any chance of a set of tracings from the tank decals so i can make a set up please?
Thanks

Hi Dodgerover,
I've done a tracing of the RHS tank graphics for you. The LHS has too many rust blebs to get a decent trace from. I'm assuming that, once the pattern is loaded into a computer, it can just be flipped over. PM me your details and I'll post it off to you.

Ian

[dodgerover]

Thanks Ian will PM now - send me your paypal address and i'll bung you a few quid or a set of tank decals when I get them done whichever you'de prefer.
Cheers

[cossackman]

No need for payment. Just pass the favour along the line. It may come all the way back to me one day! :-)

Ian

[cossackman]

Not much to report.

Got the tyres fitted to the replacement wheels and got the rear lighting done.



Waiting on the correct locking tabs for the rear sprocket and the return of the fork stanchions and a few other bits from the chromers. Still to paint the tank and polish and lacquer the lower fork legs.

[dungbug]

I'm going to be starting the strip down of my Transalp within the next few weeks, how did you clean up the engine casing (aside from a feck load of hard work and patience) as mine looks pretty much as your did.