Suzuki GT500 Cafe Racer

This stunningly beautiful Suzuki GT500 Cafe Racer was built by Tony Lloyd from Walsall. Tony’s engineering ability and attention to detail is exceptional and the build quality of this machine is exceptional.  She is a pleasure to ride with handling and brakes almost up to modern day standards.  The exhaust note is delightful and it is so nice to hear a twin cylinder 2 stroke again.

However its when the Suzuki is when parked-up that the fun really starts as it attracts so much attention everyone wants to come and have look !

Thanks Tony for creating such a lovely bike.

The following is Tony’s build blog which I have copied from his website just in case it got deleted or removed (https://jtccc.wordpress.com/our-motorbikes/suzuki-gt500-cafe-racer/)

Build Blog

Autumn 2015, winter is looming and I need a project! Another car is out of the question so I looked around for a motorcycle. My first thoughts was a restoration, but everything I looked at needed far too much money spending on it to be a viable proposition when you take into account the purchase cost and the price and availability of parts to bring it up to a good standard.

Then in November I was looking at a 350 Kawasaki import, but I was unsure so I called my old mate who I knew had a GT500 in his garage, and he agreed to sell it to me! I actually remember him buying it in the late 70’s!

It had stood since 1986 and all the chrome was very poor; particularly the wheels as these and the engine had stood in a very damp shed. The remainder of the parts had been stored in a dry garage, but they had still suffered. I bought it anyway without knowing what the engine would be like inside.

So here it is. Mostly complete, he has since found a few more parts.

First job after sorting through to see if anything else was missing was to remove the heads and barrels to see what the top half of the engine was like. I did try the kick-start, but this was seized…  not a good start! Heads and barrels came off OK and I was pleasantly surprised to see that everything was free!  fortunately my mate had wedged tissue paper in the inlet and exhaust ports which probably saved it!

the next job was to pull the engine apart and have a look to see if there is any big problems in there…  Its surprisingly good, the crank is good and will just need seals.  So the first real job will be to rebuild the engine.  Due to the condition of the remaining parts, I have decided to restore it as a period Café Racer rather than a straight restoration otherwise the cost of the restoration will be far higher than the bike will be worth.

aDSC01686

I debated on replacing the centre main oil seals for a while…  not an easy job to do as it entails splitting the crank.  In the end I decided to do it for the price of a set of seals and some work, lets face it, they have been there for 40 years!  Its a good job I did as they were rock hard and worn.  the outers on the other hand were relatively soft so they may have been replaced at some point.

In order to split the crank I first carefully marked it so I can get it back in exactly the same position.  I did this by turning a piece of silver steel to be a snug fit in the holes in two of the crank webs.  I turned the bar to a nice point and hardened the end. Then, by passing the bar through the holes in the two webs, I was able to make a nice centre punch mark in the third. The enabled me press it back together really accurately using the bar and mark as a datum.

Then I used the bolt method to force the webs apart.  Not as much force as I imagined, it came apart quite easily.  The two brass bars were made a nice snug fit between the webs so I can use them to press it back together to the same dimension.

crank apart

The bearing was removed with a 3 leg puller, but to get behind the bearing, I first moved it 5mm buy using the pry bars in the “O” ring grove to lever it up.

main bearing removalThe gearbox needs little attention, all the gears, selectors and dogs are in good condition.  the cases were bead blasted and assembly has begun.  before I went too far I wanted to clean up and glaze bust the bores.  I do have a 3 leg hone, but I never like using it in a 2 stroke due to the large ports.  In order to clean things up I turned a block of wood in the lathe and used this with a piece of fine emery paper.  Surprisingly there is virtually no wear on the bores, and its standard too!  The barrels will be next to be blasted, but I will mask off the bores first.

DSC01692DSC016963rd December.  While I waif for some engine seals and gaskets I turned my attention to the hubs.  They were quite corroded on the outside so I mounted them in the lathe and gave them a very fine skim to freshen them up in preparation for having them re-built with alloy rims and stainless steel spokes. I fitted new bearings as these were cheap.

 

hubs 1

I took the crank to a mate today and used his 30 ton press to put the it back together with the new seals on the inner bearing. It pressed together quite easily.   To ensure it went back in exactly the same position I used the silver steel bar in the webs and ensured it was perfectly aligned to the datum.  I had a backup of a scribed line on the webs as well!

crank in press 1

crank in cases

The brass spacers were used to ensure the crank went back to where it was.  tight fitting spacers were also used in between the crank webs to ensure the crank pins were not stressed during pressing.

Just to be sure, the crank was checked with a dial gauge. What is not evident from the picture is that the crank is supported by the end two bearings only in the crankcase.  To facilitate this, two pieces of 1mm silver steel were used to support the bearing at each end, effectively replicating support on two V blocks.  Thankfully it was well within tolerance!  The dial gauge is shown here on the crank web, but what is most important is that the bearings/shafts are true and in line.

The bores came out really well after the hone, new rings and small end bearings were fitted along with new head gaskets. All the engine seals have also been replaced, along with the isolastic engine mounting bushes.  While bolting the head down, one bolt didn’t even begin to tighten…  So out came the Heli-coil kit to make a nice repair.

engine 3

For now the engine is complete.  I will do the final polish when its in the bike as it will be in and out a few times as I will dry build the bike to ensure everything fits before painting the frame.

engine build 1engine build 2

I decided to make a tank as I cant source one cheap enough that I like the shape of.  Before I did this I wanted to make sure that I had clearance for the clip-ons so I made a pair on the milling machine and lathe from aircraft quality alloy.

bars 2bars 1

clip on 2

tank stree 1

The tank is not the final shape, but its a start!  I have also tacked some frame bracing into place as I don’t like the “open” design of the Suzuki frame.

tank styree 3

Here are the wheels fresh from the wheel builder with new flanged alloy rims.

wheels

I decided to drill the front brake disc…  So I marked it out and placed it on the pillar drill, and drilled the first hole…  It blunted the drill, so I used a new one at a slower speed, that drilled another two holes before it started shrieking!  In the end I had to admit defeat and buy a TCT drill bit, which stayed sharp for the remaining holes.  That disc material is incredibly hard!

The micrometer blue, and the micrometer was given to me by my Dad when I was 16 and had just left school.  That makes it 44 years old!  The blue is still usable, and the micrometer is one of my treasured possessions.

disc blue

The first time back on its wheels (well almost!) for over 30 years.  The mock-up of the build has begun, I will be doing all the fabrication on the bike before striping it to paint the frame.

mockup 1

Here are the Mikuni carburettors, they have just been rebuilt with seal and jet kits. Keen eyed people may spot the crack in the float bowl…  I will need to replace this.  I have also rebuilt the speedo drive, the oil pump and made a new bush for the clutch lever as it was worn quite badly.

carbs 11

speedo drive 2oil pump 1

 

 

 

 

clutch lever 1

I have started work on the front mudguard. I have cut out the former out of some insulation, and covered the former with tape.  Here it is with the first layer of Glass fibre on it.  I will cut it to the final shape once its been profiled to shape.

mud 1mud 2mud 3mud 7

 

 

 

 

 

 

 

 

 

here is the tank ready for the glass fibre…  I am quite pleased with the shape.  Who would have thought that it would be warm enough to work in my sweatshirt in the garden in December!

tanks 2

I will shortly be making the aluminium tank to go under this cover, but I was worried about capacity, so when I made the mock up, I covered it in tape and filled it full of water…  16 Ltr, that will be OK!  Here is the new tap, and the mounting plate ready to be welded onto the bottom.

water tankfuel plate

 

 

 

 

 

I debated a long time about the shape of the seat, in the end I went for a rounded one.  The compound curves took a bit of sanding to get right!  I will be shaping it later when its on the bike as I want to kick it up a bit at the back.  I have also moved the frame brace tubes to clear the carb air filters.  One of the benefits of a trial build!

mock seat 4seat 4

 

mock up progress

I have been learning to TIG weld and today welded up my oil and petrol tank.  The red stuff is a penetrating dye used for crack detection, so I could check for leaks.  I didn’t want to use flat ends on the tank so  i dished them slightly by spinning them in the late, an old method of metal forming.

spinning platestank 14

tank 17

I debated a long time how to make the filler cap.  I was going to thread it, but felt it might distort as it was welded on, so I utilized the old filler, and mad an adapter so it pushes on and secures with a couple of grub screws.  there is an O ring in there to prevent leaks.

filler neck 3tank 16

The dry build is finished and its all in bits again, and the frame is ready to go to the powder coaters tomorrow.  I have been busy on the milling machine making the rear sets, which will be fettled and polished once I know they fit OK.

 

suzuki 1 (1)suzuki 1 (4)

 

 

 

 

 

I know its a old milling machine…  I have no idea how old, but its a useful piece if kit, made even more useful by the addition of some digital callipers as digital readouts.  I have done the same to my lathe and it transforms it!

suzuki 1 (2)suzuki 1 (3)

 

 

 

 

 

 

lathe DRO

Today I have stripped and rebuilt the front forks, putting in new seals.

forks 1

While the frame is away I have been looking at the wiring. The intention was always to replace it, but as I will be modifying most of the electrics I decided to make a loom from scratch as this will need to incorporate key-less ignition, a modern rectifier and voltage regulator  and  LED indicators, along with a brake light switch on the front, as opposed to rear brake.

I cur the old loom apart and laid it out on the bench and noted the colours, so where possible I can stick to the original colour scheme.  I then measured each wire and made a list.  There were around 20 colours, and when the parts guy saw the list he thought he had a big order…  until he realised that many of the lengths were just one meter!

Here is the horn, and light switch being rebuilt, my eyes and fingers are not what they used to be, hence the neat little helper!  The horn switch was broken, the small mica insulator was split in half, which is a common fault, so I had to make a new one…  I looked around for some material that was resistant to heat (so I could solder the terminal) but importantly was an insulator.  I found the perfect material in the splatter shield off an arc welding mask! Perfect for the job.

wire 4wire 1

 

 

 

 

 

Today I have made the headlamp brackets, and polished the top yoke and mounted the clocks.  I tried to make the brackets a few weeks ago, but gave up.  The alloy tube I had from the scrap metal yard would not machine well.  He called me yesterday to say he had some offcuts in from a company that does aircraft parts…  perfect, like turning cheese!  It welded nice as well

headlamp brackets

I love this stage of a restoration…. putting it together, and doing the wiring… the bit most people hate!

I decided to use the none split spiral sheathing, as it looks better. The rear set on the gear lever side is on and works a treat. The battery is mounted (took me ages to think how to secure it!). The buzzer is part of the alarm system… I wont have an ignition lock and key, just a remote key fob which will turn it all on.

I pulled the headstock bearings in as I hate hammering bearings. Also I have rubber mounted items like the fuel tank, oil tank and coil, as well as the CDI unit (waiting to see if this is any good…) and rectifier…

I like the little LED indicators!

head bearingsoil tank mounting

battery 1battery mounting

 

 

 

 

 

rear set 1clocks 33

I have fitted 5mm LED’s as warning lights for the ignition, indicator warning, high beam, and alarm.  No Idea how long they will last, but I have had one flashing in the car for 5 years…

I also picked up this steering damper on Ebay on Christmas day. I put a snipe on it and won it for £5!it fitted perfectly, just needed to drill a couple of holes in the frame. It was off a Cagiva Mito

stereing damperclocks 44

The rear brake took a bit of thinking about…  got there in the end though.  I may have to get that swinging arm bolt chromed though!

brake rearset

So far I have only put two jobs out, the frame painting, and the seat trimming,as I have tried to do as much as I can myself.  I could have painted the frame, but in the past I have found that it creates sooooo much over spray in the garage that I prefer to get it done, its fairly cheap as well.  I wanted the seat to look nice, and I don’t have the skills, or the machine to sew multiple layers of material.    The seat was trimmed by Aldridge Trimming, a company I have used for 40 years, and they always do an excellent job.

 

IMG_0234SEAT 23IMG_0251

 

 

 

 

 

 

I have been working on the wiring… As I didn’t want to use an ignition switch, I have used one of the cheap (£4) 12V remote control relays  off Ebay. As this has a learning mode, I have also been able to integrate it with the alarm system. So now with one remote fob, I am able to turn the bike on and off, and set the alarm. it works a treat! I have hidden an over-ride switch just in case though!

the remote works two relays as the Suzuki system switches the power on on one circuit, and disconnects another circuit for the ignition. In fact the handlebar kill switch confused me as on was off, and vice versa.. I spoke to the original owner and he confirmed he had swapped the handlebar switch 30 years ago! It would have annoyed me to have on and off the wrong way, so I milled the engraving off and filled the resulting depression with some paint!

I also had to make a new twist grip as the one with the bike was incorrect.

The curly bit of wire is the antenna for the remote.

remote 1

IMG_0252seat wire

Well…  after much deliberation, playing with Photoshop…  black tape…  I decided to paint it orange.

 

gt500 suzuki tank 1

They say a build like this is never finished….  one of the difficult things to do was start the bike, as my foot hit the foot rest….  so I decided to make a folding one, so I can push it up out of the way.  the little spring washer is to stop it rattling and keep it in the up position when needed.

foot 44foot 22

 

 

 

 

 

 

The tank is now bolted on.  I have rubber mounted it, along with many of the electrical components including the coil to try and prevent failures from vibration.

tank 22

Initially when I tried to start the bike there was no spark.  I checked the OHM reading on the various components and the  ignition coil was out of tolerance.  I bought a new one from Rex’s Speed Shop who were very good with advice on the phone.  After fitting this the bike started, but it was hard to start.  The stator coils for the CDI were “just” in tolerance, so I replaced these…  it now starts easily.  I guess you have to remember these components are over 40 years old…

wire 33cols 1

 

 

 

 

 

 

As part of the engine build, I lapped the flywheel taper onto the crank with some lapping paste as this prevents attrition on the surfaces and is good engineering practice…  of course when I came to remove it to replace the coils…  it was hard on there!   Had to make this puller to remove it!

puller 1

As ever with a rebuild there are problems…  I noticed that one of the oil lines to the left hand cylinder had large bubbles in, which despite bleeding kept appearing.  a sign of a problem.  I took the offending pipe off and found one of the one way valves didn’t work correctly.  Difficult to take apart, but I managed it and found the ball bearing was stuck in the spring.  A little tweak of the spring saw it fixed and back together.  all four oil lines are now full with no air!

oil line valve

The finished bike as it left “the factory” (i.e. Tony’s workshop).  Since then I have changed the number plate, taken the exhausts back to bare metal finish and replaced the fuel cap with a brand new one.  I’ve had a few nice runs so far and intend to do more over the summer.  Some more pictures below

suzuki gt500 t500 cafe racer (7)

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