GT750 startup 2020

As usual, instant start on the GT. First ride this season. The spring has been horrible cold so far. Was snowing for a couple of days ago. Will enjoy the short MC season on the GT750 this year and hopefully the GT380 will be on the road the next year.


My GT750 A tank is back from repair and has got a new paint. My nephew Thomas has once again done a fabulous work on this. I’m so pleased with his work.

On my ride to the classic Suzuki rally in Denmark last summer i had an accident and got an annoying dent in the tank. Now it’s all gone 🙂

🙂 🙂

Tachometer face

Making new tachometer face. This is learning by doing. Very much experiential engineering. Just have to give it a try and see how it works.

Not difficult to cut the 1 mm aluminum plate using bandsaw. To make the circle using the scroll saw went even more easy then expected. Made the disk a bit wider than the printed tachometer face. Since the faces are printed as sticker lables it’s easy to mount on the alu disk. Holes were drilled and the edge grinded.

Not 100% happy with the result. The alu disk is much thicker compare to the original, giving pros and cons. Stiffer and more solid, and more easy to drill. But look at the lenses, they don’t match the thicker plate. I can mill on ther rear side using a 12mm end mill (don’t have that) or make new lenses on my lathe, if I can get hold of proper acryle material. Time will show what I do.

3D printed gauge house

My very first 3D print ever….

Still a sample print. The final one will be printed in white filament.

Spot on target, not bad for the first 3D print ever done by me 🙂

The material seems to be more solid compare to the 48 years old fragile plastic.

Fork top bolt

What to do with the top bolt of the fork leg ?

Step 1: Sand blasting as shown on the picuture above.

Step 2: Grind and get rid of all remains from the old chrome.

Step 3: Use fine grit size on the sandpaper to obtain a shiny surface.

Step 4: Start electro nickel plating. As shown previous on my blog I use the same old bath with the same solvent I made 7-8 years ago. The nickel anode is the only part that needs to be replaced after some time.

After few hours (4-8 hours total electrolyze time) the bolt will be covered with nickel. The gray surface needs to be polished to get shiny.

Done :

Clutch and timing cover

Polishing the engine cover on the right side:

Phuu, a lot of work, dirty work as well. Dust all over my face.

I have three engine covers to choose from. Two of them have some very bad scratches, too bad to ever look good again. Got hold of an unused one, the new type with 1500cc oil level label.

The bad ones:

Parts for the timing will be removed and reused in the new cover. One of them has a very good nylon gear for the timing assembly.

Timing cover:

Before and after one hour of grinding and polishing. Had to grind off a lot of material to remove some deep dents and scratches. Still some scratches left but the cover will be replaced later on with a J cover with engraved Suzuki logo. This is a later model with a sticker in the middle.


The outer housing for the gauges was a disaster. Previous owner had cut off a big piece to get space for an unoriginal ignition switch. Was lucky and got a new housing in a good condition.

The face of the speedometer looks nice. The tacho face has dents and is quite worn.

The needle is also different on the clocks. The 72 model should have chrome in the middle, not white as on the tachometer. The speedometer is all OK.

In addition, both inner housings are in bad shape. Cracks and missing parts.

Can replace it all, but not easy to get 48 years old gauges in a good condition. I also want keep it as original as possible when it comes to the look of it. Therefore I will not mount later models. And I have always wanted to restore gauges and this is the perfect time to do it.

New tachometer face:

The one to right is the damaged one. I scanned the tachometer face and got it edited in SW on my PC. Handed the file over to a printing service and got six new prints as stickers. I’m very pleased with the results and the colour looks to be spot on.

Will make a new aluminium disk without dents.

Inner housing:

The image above is for the tachometer and the one for the speedometer is just as bad. What to do? Hmm, lets give it a try. I can draw new ones and get them 3D printed.

Sketching up the measurements on my sketching pad and will try to do the design in Autodesk Fusion 360.

But first I have to learn how to use the SW, Fusion 360 is all new to me.

A simple trial design:

This was fun. Pretty sure I will get it done, and it will be good as new. The image above is not correct, only a test piece. I will post the final files on my blog if anyone wants to download and print their own.

Not sure when, but it will for sure be done if I get this right. The face of the tachometer will also be uploaded.

Next day:

The learning curve of Fusion 360 was not steep, quite easy after few hours of watching YouTube and I did some trial design.

A bit more tricky to figure out the correct measurements from the worn clock housings I have. The drawing from the K parts manual can’t be correct, will never fit.

After studying Ebay and watched carefully on photos from J/K types, this must be the correct one. Fits well comparing against my broken parts.

Image from Ebay:

Think I got it, the first design of the Tachometer house is done. I left out some of the profiles since I don’t see any need for them.

Hope to get the first trial print at work in about two weeks time. Not sure about the quality, but later on I will have access to a much better printer and can use white filament as well. The first one has to be painted white. I’m so exited to see the result 🙂 One week of vacation now before I continue with any 3D printing.


Got a surprise when starting to assemble the cylinders. Some of the 8mm stud bolts where missing and had been replaced with 6mm bolts.

This is what happens when working on a 48 years old project. Previous owners must have been too careless while mounting the pipes, as usually, too much torque and the threads are gone. A bit odd fix. They have used 6mm insterts in three places. I can’t have a mix of 8mm stud bolts and 6mm bolts. Not on a bike as stunning as this 🙂 So, what to do ?

Having a lathe is a big advantage while doing overhaul on a bike, a worn out bike.

Made four new studs. One original with 8mm threads in both ends and three with 8 and 6mm. One of the 6mm came out a bit bent, will fix it.

Done ! 🙂

Threads :

I did a refresh of the threads on both the bolts and the nuts. Not to get a surprise during the mounting.

10mmx1,25mm fine pitch threads.

Piston rings:

Before mounting the cylinder, make sure the gap in the piston ring is above the pin located in the groove.

Mounting of the cylinders:

Mount the gaskets and start with the cylinder in the middle. Apply some 2-stroke oil and slide the cylinder down. Don’t forget about the position of the piston ring to close above the little pin. Should slide easy down, not needed to use any force.

The last one and it’s done.

I was not able to find any torque settings for the cylindres, only for the cylinder head. Since there is no space to use torque wrench on the nuts I used the tools I had and fasten using sensible amount of torque 🙂


All of the cylinders have plugged SRIS outlets. I will therefore mount the case without the SRIS valve no.17. Dont’ see any issues of burning a bit more smoke at startup.