Part 8 - The Battery Box

The battery box was not supplied with the bike when I purchased it and these are near impossible to obtain so I decided I would make one. After looking at the parts catalogue I could see that two variants were used for the 1979/80 vintage. I opted to copy the simpler of the two.

1979 Battery Box

This still seemed a tad complex to build from scratch so a simplified version was mocked out of cardboard.

This was then measured and drawn (very roughly)...

A local fabrication company created a copy in mild steel. I was very fortunate in that my brother-in-law Geoff works for the company. He arranged the work and gave me the item as a birthday present along with a few beers. Is that not the best birthday present ever?

I am guessing that if you don't know my brother-in-law Geoff, you may have to grease a palm or two.

With a little tidying up and a few genuine Suzuki grommets it is ready to offer up.

All tidies up.

Perfect git.

The item fits perfectly and the battery fits very neatly inside. Naturally, this will be removed, de-grommeted, primed, enamelled and refitted with the battery inside. Nice!

Part 7 - Silencing the Noise

Silencer with rivets drilled out.

According to two of my neighbours, my TS250 is too noisy. To be honest they are probably right as there is clearly no baffle material left in the after market silencer. The silencer is riveted together at each end and is clearly not designed to be serviced which is a shame. On the other hand, it has never stopped me before.

Firstly after removing the can from the bike, I removed the end plate and drilled the rivets holding the end cap in place. On this particular can there had been some damage on the endplate on the engine end of the silencer. It made sense therefore to remove this end and make the repair at the same time. Given a free choice, I would have taken off the other end as it allows the packing material to be packed tighter at the engine end where the baffle material gets the most abuse.

Once the endplate was off, I proceeded to remove what was left of the old baffle material. This was in a very poor state and it took a lot of effort with old hook ended brazing rods to get it all out.

Old baffle material being removed.

Empty Silencer.

Once cleaned out, a bag of 2 stroke baffle material from eBay was packed tightly into the silencer and the end cap was riveted back on.

Adding new baffle material.

It doesn't look it, but it is very tightly packed.

Pop in the new pop rivets and all is good.

Easy really. The bike now sounds great. To be honest it is still noisy, but who cares, it sounds great.

The exhaust used almost all of this bag of baffle material. Less than £5 from eBay.

Part 6 - The Carburetor

After the success of a easy engine start the bike went for it's 'daytime' MOT and passed with flying colours. However, the subsequent extended ride home left me somewhat disappointed. The carburetor was clearly not working too well.

The carburetor had pretty much been ignored during the rebuild. It was clearly time to re-furbish it.

I purchased one of the Keyster kits available here in the UK and proceeded to dismantle, clean and resemble. I don't have ultrasonic cleaning facilities so some very small nylon bristles were used. The Keyster kits include all jets and float valve etc. and once fitted leave the carb looking very tidy. However, during the rebuild I noticed that the needle ring fitted to these machines, was missing from the top of the needle.

The Kitchen Worktop Makes a Great Bench

This is something of a 'gotcha' as many of the models don't have this and can easily be missed when following a service manual. However, it can make a big difference to the running. During the search for this elusive part I discovered that there are many different throttle sliders, some that use a needle ring, some that use a 1mm washer and others that don't use a ring or washer at all. This makes things very confusing.  

Missing Needle Ring

In the end I managed to source the item here in the UK (Martin Crook). On this particular model of Carburettor the needle ring fits on top of the needle with the spring below. When this is assembled the ring is responsible for lowering the needle into the needle jet by exactly 2.5 mm (99 thou) from the circlip.

One interesting, albeit, confusing thing is that the plate that fits on top (15) to locate everything as two small pressings which protrude, one from each side. This prevents the needle ring (17) sitting flat against the plate. This causes the needle to be sprung to one side slightly. I assume there is a good reason for this. However, this does seem rather odd and it makes it tricky to locate the slider without fiddling with the needle through the air intake of the carburettor.

After many hours of discussions on the Suzuki TS forum, suggests that either the plate may be the incorrect item, or that the needle ring should not be present. As each parts book and service manual shows the needle ring in place. I decided to simply re-engineer the plate and remove the 'bump' and reassembled the carburettor. After the first test run, it was clear that the ring should be in place and the slight modification to the plate was the correct course of action. Needless to say that there are many confused TS250 owners still struggling to understand what the bumps are for, me included.

I guess time will tell if everything is in order and that the mixture is correct across the operating range. I suspect the some small adjustments may be required as I use the Bike more. Either way I am happy for now as it runs well and starts easily.

Part 5 - Engine Start

This will be a short post, as the engine, after its full rebuild, started straight away. Nice!

Part 4 - Rewiring

When the bike was purchased, only the bare essentials had been wired using the blue and brown wires from some mains flex. Naturally, this was removed. A complete harness was then built using new thin wall cabling. This proved to be a fairly simple task once the customised wiring diagram was developed.

The Ignition System

The bike came with all of the necessary components for the ignition. This included the short wiring stubs the connect between the electronic ignition, coil and magneto. This saved me some time. However, none of the other parts were supplied. For example there was no rectifier and no regulator.

The Magneto Generator

The stator on the TS250 contains three coils (actually it is four as the ignition has a primary and secondary coil wound on the same former). In my case the ignition coil(s) was simply connected to the electronic ignition using the original connectors. However, the two remaining coils, the lighting coil and the charging coil, needed some attention as there were some decisions to be made.

The Rectifier

The rectifier is responsible for converting the alternating current (AC) from the  charging coil to direct current (DC), suitable to charge the battery. The original TS250 uses half-wave rectification, which is a fairly crude approach, however, as it is  effective enough, I simply purchased a new Suzuki rectifier. These items are not expensive and an after market one would have been just as good.

Charging

The charging system involves taking the output from the charging coil and connecting it through the rectifier to the battery. The challenge is selecting the correct connection from the charging coil as there are two.

There is a yellow/white wire and there is a green wire. The yellow/white wire has a higher output than the green wire and is used when the lights are on. The green wire is used when the lights are off. Therefore, this means that the charging circuitry is routed through the light switch.

Buy the correct coloured cable.

Im my case, I have no lights other than a brake light. Therefore, I can keep things simple and simply use the green wire. The diagram shows the full circuitry for my bike, including lights, albeit without indicators. The circuit diagram was created by scanning one from a page of the workshop manual and then simplifying it using Photoshop.

Creating the Wiring Loom

For this I cheated. Once the wires were laid out across the bike, I use a product call Spiral Cable
Binding. This stuff is awesome and makes wiring a bike a breeze. The really good thing is that it makes it really easy to re jig the wiring loom when it is time to add the lights.

All ends were created using soldered bullets and were connected using the single and two way bullet connectors. These are simple to fit especially if you are handy with a soldering iron. Making a small wooden jig to hold the bullets can be a great help.

The Regulator

The regulator is designed to maintain a constant voltage irrespective of the speed the engine is running this helps the bike from blowing bulbs etc.

A regulator can be hard to come by as it needs to be an AC type. The regulator sits across the output from the lighting coil and the earth/ground. To date I have decided not to bother as I do not have any lights at the moment. However, having spent the first 20 years of my career in the electronics industry, I have a mind to build one. If I sort it out I will post details.

UK/USA Differences

The main difference between the US and UK wiring is that in the US the lights were designed to be permanently switched on. This means that the charging circuitry can be much simpler and does not need to be routed through the light switch.

Part 3 - Removing the Blind Bearing using a 'Lewis Bolt'

There is a blind bearing on one side for the gearbox shaft, this was a challenge to remove. Despite many discussions with experts on the Suzuki TS forum, the thing would not move. However, a trip to the Roman Baths in Bath helped solve this one. At Bath they had an exhibit that described how masons lifted stone using a Lewis Bolt.

The blind bearing to be removed.

Using some DIY brackets to create a Lewis Bolt

Place the bent bracket in first and then fill the hole with the others.

Find a suitable clamp.

Pop a bolt through the lined up holes.

Draw it out.

Part 2 - The Engine Rebuild

We have separation.

This was the first thing on the agenda. The engine had not been split before and after 35 years proved to be a tad tricky to get apart. However, after much patience and the purchase of a flywheel puller, it eventually came apart cleanly.

All bearings were replaced as were all oil seals. There is a blind bearing on one side for the gearbox shaft, this was a challenge to remove. Despite many discussions with experts on the Suzuki TS forum, the thing wouldn't move. However, a trip to the Roman Baths in Bath helped solve this one. See the separate post on how this was done using a homemade Lewis Bolt if it is of interest.

All bearings were replaced with Koyo bearings and a local engineering firm rebuilt the crank, rebored the cylinder and supplied the piston and rings. During the re-build many new parts were used including stainless Allen bolts throughout and most importantly, a new Suzuki NOS reed valve.

The strip down commences.

Take away curry containers are so handy.

The heart/oil pump.

More bits.

Gearbox kept in-tact for now.

Removal of old main bearings

All ready for the rebuild.

Like a work of art.

Time to re-unite the crankcase halves.

All Done.

Barrel with new piston.

Lots of new Suzuki parts including a very expensive new reed valve.

New studs for the head.

Back in the frame.