Barrys Yamaha DT1!

Post date: Mar 16, 2013 10:1:27 PM

What has been happening at my workshop is partially secret. The non secret is my Yamaha 1968 DT1 250cc trail bike rebuild. Yeah, I know it is just an old poxy trail bike of small capacity. But it is the original mass produced trail bike. Bought out at the time when Vietnam was on. There was the assignation of Martin Luther King and Kennedy. What a time in history to produce a cheap, very good escape from it all trail motorcycle. I bet even Kenny Roberts rode one. (See the movie “On any Sunday 2”).

I bought the DT1 bike a few years ago. It came in two lots and wasn’t cheap. But I have also ended up with an RT3 as well. Many of you may recall my off colour 1973 DT3 at the Spring creek rally a few years ago. Well this one is better, much better. The bike came with a lot of spares. New conrod kit, but no bottom end bearing. Knackered gearbox, Forks which were seized,a bent, cracked and repaired frame along wih a crappy seat. But the wheels were reasonable and it had a great bore and piston but no wiring loom. The engine was already out of the bike. and had been assembled empty. Hence so many spares.

Progress was slow mainly due to a lack of room in my garage. This was something that has to be addressed.

I favour sending the oldest boy (Now 19) off to the foreign legion for many years. (But Debbie does not) This would free up a room which the bike storage could expand into by removing a false wall I put up 15 years ago. More space + happy face but back to the DT1. The non-operating forks were stripped and new seals and oil installed with more work to be done on these later. The exhaust was in good condition so it got cleaned up and repainted. I stripped the engine cases and found it was all relatively clean. All the cases all ultrasonically cleaned along with the carburettor and a few other parts. The crankcases were buffed up and the barrel given a quick hone. The big end bearing was sourced via e.bay along with a complete early gearbox, spare clutch and a few other engine internals. At this stage I also purchased a wiring loom for it, which turned out to be a different trail bike loom. Fortunately only difference was 2 wires had to be repositioned.

The crankshaft was rebuilt with all new bearings and seals. The new gearbox and clutch etc were checked and refitted with new gaskets and rings. The engine went back together and at this stage I did not get the engine cases repainted. More later on that. The engine was then refitted to the frame with the wiring loom.

It started up.

It sounded sweet.

All the gears are working well.

The engine was a runner!

Bodywork.

The rear mudguard did not fit properly and this was eventually traced to the frame brackets. They had been broken off the frame and what was welded back on was not correct for the mudguard for this model of DT1. It had probably had a different mudguard on it because when I got the bike, all the parts were sitting loosely on the rolling chassis.

By luck or upstairs godly intervention I managed to get onto a guy in the Coromandle with a load of parts he was quitting, for a 1968 model. He could also tell me a lot of details I did not know about. Apparently the first model had an aluminium front mudguard. Super hard to find as you can imagine. My steel one will have to do for now. Another interesting piece of information was the white rubbers dampers for the mudguards. Not black like all the others and also the weird connection pieces for the rear mudguard.(I still only have ½ of those and don’t understand why they are all there. The first model also had a small tacho which is also peculiar and this was missing. Lo and behold

a great set of instruments came up on e.bay but they sold for over $400 US and not to me! A shorter seat was also used as mine was crappy. I bought all the parts including another frame and fortunately for me a relative was going up to the Coromandle for that week and picked up the parts in his car. A dozen beer later and. A good rear mudguard arrived along with a damaged small Tacho and many other good parts. It was now getting exciting. I was getting somewhere. The first job was to check out the new frame with the better rear mudguard.

It mounted up correctly.

Seat.

The seat base I had was pretty tired as someone had tried to repair it. It just didn’t fit properly.

I had to do a lot of welding of seat cover tabs and cracks to get the base back together properly. Then there were many hours of bending pushing and shoving to get the seat base to fit correctly onto the frame and clear the rear mudguard, whilst sitting onto the rubber blocks properly. Finally after a few cuts and rewelds along the seat base side. I was there.

The original frame was found to be bent at the backend, which the base had been made to fit previously. The seat foam was pretty good and was reused and a new seat cover was bought from the USA and fitted.

Finally one part was completed properly!

So there she stood for many months as other jobs jumped the queue. The only advance was the one part I still needed.. The original air box with fluted sides and one was duly found on e.bay and shipped to NZ. It was complete with the air filter. This is why I think they have all been changed due to the big price for the air filters. The top of the air filter is the top filter cover. The louvered sides may have let in water from rivers which would have drowned the bikes in rivers. The later model air box’s would have been a big improvement.

I got a call to put some bikes and car into the Levin show recently. So being into that, I accepted and the DT1 was going to be there as she did look pretty tidy as she was. BUT. Then I thought. Bugger it, I’ll get the frame and paintwork done properly. I have found a reasonable painter recently, whom has done some other work for me. Off to the paint shop and a deal was done. He had 2 weeks to get it done. All the parts were dropped off, along with the fork sliders and a new side cover decal.

The frame, swingarm and repaired side stand etc were taken to the bead blasters and powder coaters. These were done in Upper Hutt. A very good job was done over the week I was away at work, at a very reasonable price. More parts were dropped off on the way to work for rezinced the week I was away. The plan worked well. I collected the zincing and frame parts. I had plenty of time alone at home as Debbie was in Auckland for the week with one of the boys.

Thank God for the internet. I could print out exploded diagrams of how a lot of the fiddly parts are meant to go back together properly, as from the factory. I haven’t got a parts book for this bike yet.

Many hours of work and she was coming together.

Unfortunately the paint work was not done. His panel beater had let him down. To cut a long story short the paintwork turned up looking very sharp.But that was at 3 pm on Saturday. That was when I was meant to be on my way up to Levin. By 10.30pm that night it was nearly together but not without the normal problems of finding the rubber parts were not fitting correctly. Wrong size and so forth and not to mention extreme tiredness which got me to the stage where you just have to leave it. Early the next morning, some parts just fitted by magic or something else. The new chrome headlight surround would not hold the headlight. It is for a different stlye of headlight so I had to use the damaged old one. Another piece to be still be finished properly. But not the tail light bracket!! Great drama to get it to fit without damaging the paint work.

Then the final part, but one. The standard Yamaha carrier.

Another mission. Finding the right length bolts and washers.

The final part. The metal clip to hold the battery.

I had to make.

DONE.

She still needs the shock springs re chromed and the headlight chrome sorted. The other thing is the bolt on tank has gone west, or it maybe they were short lived from the factory. They would have been a pain to remove if required to when trail riding. Perhaps it was only on the first run, a bit like the air box. Also the little stinger on the exhaust which I will reproduce one if ebay dosen’t supply me one.

Keep on riding safe.

Barry Drummond.