DT 175 Resurrection

[Signal]

After looking for a long time the almost right DT 175 came up for sale and today it arrived. It has not run for 15 years, and I have the ownership papers very important for registering a bike here.

Ideally, I would have liked an older model but this will do.

It is mostly all there but very rusty, luckily the tank apart from the dents is not rusty inside.

It has compression and spark, and I am partway through cleaning the carb, hope to have it running tomorrow and see how bad it rattles.

 

[Downeaster]

Following...

 

[Signal]

I got the bike going the next day. The idle jet was blocked solid, the choke knob is missing and the remaining part of the choke pull was bent.
Got that all sorted and using some 2 stroke premix the bike fired up in short order.
The kick start lever is very worn.
The auto lube is working, the neutral and oil light and indicators all work although with no battery on a 6V system they are erratic.
My ear is not attuned enough to tell if it needs a rebuild no obvious clunks though.




The fork lowers have been cleaned up and lacquered (rattle can) new seals on my list. The staunchions have very little rust a bit that can be hidden on each leg. The gaters did their job well.
The rear light is the same as an XS one I had and the XS one was in better condition and swapped straight over .
The rear guard upper is plastic and over time the surface has broken down but it has polished up ok. This bike is going to be done to a reasonable standard not the sort of restore work some of our members do, looking at you Mailman.
The metal inner guard which is zinc plated I sand blasted and rust treated then painted.
The front wheel chrome has polished up OK with steel wool and oven cleaner.
The spokes and nipples need replating. The rear wheel is toast but have some ideas.

Taking off the clocks I found the speedo disconnected and running it up on a drill it makes a horrible scream. It looks the same as a 1981 XT 250 one so that sort of doubles my chances of getting one.
The clock mount was broken but I managed to repair it to an ok standard the ugly bits wont be seen.




The seat is in at the upholsterers and I have a decal set for the tank and side covers coming.
The steering felt a bit notchy but a repack is not going to do the job. Tapered roller set on my list.


I have a rather full shopping trolley at Yambits with the price of shipping I don't want to order too soon as I keep adding to the list.
The work continues...

 

[Raymond]

That all sounds like really promising progress. You must be very pleased to get the bike to run?

 

[GaryInVA]

Will follow this. Glad it turned over when you got it. I am rebuilding a 1979 IT400 with my son. It sat in a garage since 1990. It ran when put in there but when I got it the motor was locked up. Getting ready to split the cases to have the crank rebuilt.

 

[Mailman]

This bike is going to be done to a reasonable standard not the sort of restore work some of our members do, looking at you Mailman.

Man………just because I polished a few things like carburetors and the underside of fenders, people think I’m OCD! Well…………maybe a little.

By the way, I like the save you did on that instrument cluster. Did you use JB Weld on that?

 

[Jan_P]

My ear is not attuned enough to tell if it needs a rebuild no obvious clunks though.

Is a possibility to upload a video with sound both sides high and low. Cold start ..
And watching the smoke at the same time.
Even though the carb can make it rattle before serviced.

 

[Signal]

Mailman, yes you and I did use JB weld to fill in a manufactured pocket in the base to give it more strength.

Jan P I could stretch my abilities and upload a video however I have a good mechanic friend that visits often, he is just a bit busy racing and preparing for the summer series that starts this weekend.

 

[bosco659]

I’ve got an Autolube tank for that bike as well as a printed service manual. If you can use them they’re yours for the cost of shipping!

 

[Jim]

racing and preparing for the summer series that starts this weekend.

Your sidecar rig(s) racing this year?

 

[Signal]

Bosco thank you for the generous offer if I get stuck I will send a pm.
Jim yes the 700 is racing this year it has been apart more than it has been together. Went to a crossplane crank it snapped the crank twice in short order. Changed crank back to big bang and last weekend at the Southern Classic it melted number one piston due to a fuel issue. They did manage to gain a second overall in points in the classic register series. Next race is Boxing day at our home track, no holding out much hope of a win there are too many big HP BMWs.

 

[Signal]

I have been having al sorts of problems with emails from this site ending up in the spam folder and the site suspending my posting privilege's. I had not changed anything but hopefully got the setting adjusted properly now.

I have been working steadily at this, most of the hardware has been plated, the seat has been recovered. With the help of a 20 ton press and another set of hands the swing arm pivot bolt came free. So the chassis is completely apart.




The transfer kit for the side covers and tank have arrived, and I managed to “plastic weld” the cracks in the side covers. The front and rear guards where badly oxidised but they have come up well with a lot of scraping and sanding. A mate has offered to paint the tank and side covers in lieu of payment I get to sort the wiring on his XS tracker (gulp). Possible nightmares coming.

The forks have been rebuilt with new seals, for future reference and to help others the damper hex is 14mm.


The other plastics have also been cleaned up air box inner guard etc. The tail light is the same as some XS 650's I swapped a better XS one onto the DT.


I turned a wood box into a large electrolysis tank using some polythene sheet and a rebar frame. Then used it to de rust the exhaust system. The rust turned into the black oxide that was easily brushed off with a wire brush and running water. I did the same to the muffler.


I took some photos of the early stages of the electrolysis as it was interesting to me to see how the cloud of material progressed in the tank following the path of the electrons from the anode, but I thought it would be more directional. Some of the members here may be able to explain it.



Unfortunately, I was trying to suspend a small anvil in the tank to de rust it and dropped it and it punctured the liner so I will have to re line it before I do the swing arm.

The pipe is now painted and hung on the wall ready to go. Before and after shots.


The front rim has cleaned up with wire wool and oven cleaner but the rear one is toast I can get new rims and spokes off eBay. They sell the rims in pairs I will ask the seller if he will split a set and sell the rear only. The spokes I think I can refurbish.

I am still undecided about the frame but will probably sand blast it.

The work continues …

 

[Jim]

That exhaust turned out nice. Was there much carbon buildup inside it?

 

[Signal]

Forgot to add the triple clamps are ready to go, and the steering head bearings are here. I also bought a new kick start lever as the old one could have been repaired but would take a lot of work and a new one was less than $50.

I have also bought a dent puller following good reviews on this site. Will have a lash at that later.

 

[Signal]

Hi JIm, thanks. No not too much carbon I burnt it out before soaking. Used a map gas flame to get the fire started then put a vacuum cleaner on blow a few glowing tracers but nothing spectacular.

 

[Signal]

Bit of an update. I have been busy rewiring an XS tracker as my part of a contra deal in exchange for some paint and panel work.

The wiring was a complete mess so I have started again, I expected as much and I am not complaining but it has taken me away from my main task. It is quite enjoyable actually also making some mounting plates and other bits that need doing.

I also had to make some new parts for the RD that broke on boxing day and the next meeting is February 3rd and 4th but it will be all go again tomorrow night.

I ordered a new rear rim for the DT and it arrived so at the moment I am blasting the hub in preparation for painting. After some research I will paint the hubs with matt black VHT brake caliper paint (rattle can) . After it is fully dry you bake the parts to achieve full hardness and chemical resistance. Need to repaint the front hub and re zinc the spokes as well luckily the rim was saveable.

I managed to get all of the rear spokes undone without any breaking but some needed a fair amount of heating. I have started re plating the nipples and spokes but my power supply died. I have been unable to repair it so rather than replace it with another Chinese one I have ripped and old computer apart and will use the power supply from that and a buck converter (both also from China).

When I get the spokes done the fun will start relacing the wheel which is all new to me. Fortunately I have been watching Dale Sweger on YouTube. He fixes up dirt bikes and is always up to something interesting and I find his delivery and temperament very watchable. Here is a link to his channel.
https://www.youtube.com/@montana2strokeracer

The frame has been blasted and painted it is not as good a job that I usually get done for free. But my mate is too busy at the present as it is the height of the racing season so I paid my money and took my chances and got an ok job. I think I need to learn to spray paint. Photos to come.

Just placed an order for hopefully the last parts I need from Yambits and hoping to have a rolling chassis again shortly. Blown clean through my estimate of a rebuild cost and still need rim tapes, tubes and tyres. Hopefully the motor will just need a Dulux recondition but it not a disaster if it needs a rebuild it would give me an excuse to get the die grinder out.

 

[BowlingSS]

Good luck. Always liked the Dt’s. I worked on a lot of them in the 70’s.

 

[Signal]

Work has been progressing.
Made a new chain guide for the swing arm out of nylon, I never have had much luck turning this but was told to use sharp tool steel. What the difference easy to turn and a lovely finish.

New bushes and spacer in the swing arm are in.


The spokes are all plated now and just waiting for the paint on the rear hub to mature (7 days) before baking in the oven. If that turns out ok will plate the spokes on the front and paint the hub.
Waisted about 1/2 hour looking for the speedo drive only to realise it is integral to the front brake carrier.
Cleaned up the wiring loom with a tooth brush and detergent it came up well and only a couple of connectors need replacing.
The tank and side covers are being painted now.
Started putting it all back together I want to get it to a roller and then start tidying up the engine.
Will post photos of the rear wheel before and after rebuild hopefully soon.

 

[Signal]

Got the rear wheel back together. While on the job I put new bearings in. The spokes came out well in the end although some of them have been through the plating bath 4 times.
I was a bit careless when disassembling the rear wheel taking only one photo of the spoke pattern. This caused a few head scratching moments, lesson learned I took plenty of photos today as I started on the front wheel.
This was my first time doing this and compared to my first time truing a crank the wheel was a walk in the park.

The XS rewire job is done and the DT tank has been stripped back to bare metal and being prepared for painting.
I ordered a new set of chrome handle bars and they arrived painted silver about what I have come to expect from dealers these days. Luckily the DT came out with black or chrome bars so the bars will be painted black. The original bars were bent and rusty beyond redemption.

 

[Signal]

I have been busy in the workshop but working on other things. I wanted to fit a new ignition to a mates XS sidecar for him to trial at a meeting at the end of the month which is the last before the winter lay off. Over the winter the plan is to boost the bikes compression and convert to methanol, but I wanted to get the ignition on and tested so when we have problems, we know the ignition is sound.

Back on to the DT:

The front wheel spokes and nipples have been replated and the wheel relaced. It was more problematic than the rear was due to the design of the hub it had 3 sets of inner spokes and only one outer. You have to install the inner spokes first because as you progress with the lacing you can’t fit them in later. If you make a mistake it takes a while to sort out and I made a lot of mistakes.

All sorted now with new tyres and the bike is a roller again.



The tank has been painted and I put the transfers on. It was a battle as I think they had been sitting around for a while and the backing tape did not peel off easily. I found that gently heating with a heat gun helped. I will drop the tank and side covers back round to be clear coated on Friday.


Next up is the motor, it was filthy, the oil tank had a different cap to stock and leaked 2 stroke oil all over the motor.

It turned out to be a boon as the oily crud has preserved the aluminium and it looks as if it will be easy to get it looking good again.

I will give it a blast with soda while it is still assembled. I will then take the head and barrel off for inspecting the top end and checking the crank for play

.