Browse Category: Suzuiki GT 380

Kick starter and gear shifter

Two more parts done today with new rubber mounted. The kick starter and the gear shifter.

The kick starter was only cleaned and polished + new rubber mounted.

The gear shifter had some bad parts of chrome coming off. I did a gentle sandblasting of the ugly parts and nickel plated the entire shifter without removing the old chrome. Came out pretty good I think.

I didn’t do anything with the odd looking edge of the gear shifter. This is how it was made from the factory 50 years ago.

Headlamp

Headlamp housing mounted:

Got a bit confused due to the drawing. It shows a headlamp bolt with flat head:

Looking up the part no and looking at images, they all had rounded heads. I took an old original Suzuki bolt. After sandblasting and nickel plating it was good as new.

Fender and front wheel mounted

Mount the fender before the front wheel.

New fender mounted

Two 8mm 1,25mm pitch bolts on each side. The lower bigge hole (10mm 1,25mm pitch ) is for the front drum brake.

The front wheel:

I have not found any parts manual for the J model in pdf format, only from K and later, but this link on the web shows the J front wheel with the drum brake:

https://www.cmsnl.com/suzuki-gt380-1972-j-usa-e03_model16106/partslist/81501.html#.YvLRgXZByUl

Dismounting and restoring the front drum brake + nickel plating

Some pictures to help out the assembly process later on. A lot of rust but all the parts are present 🙂 Not possible to source any new parts for this rare front brake. Starting with rust removal and cleaning. The chromed parts will be sandblasted for removal of the old chrome and rust pitting. Thereafter I will grind and polish back to a shining look before I nickel plate them using my old nickel plating kit.

Cleaning:

Polishing:

Three of the parts looks quite nice after some polishing. Can be used as is. No need for nickel plating.

Sand blasting:

Sanding:

Depending of the parts I’m using different tools. Dremel, rotating disks or the lathe. Starting with 80-100 grit sand paper until I get a nice finish using 1200 grit paper.

Nickel plating:

The nickel plating bath is 10 years old and is still function well. The cost is like “nothing” compare to shipping parts abroad for rechroming. After some yars I only added water to the bath and bought a new nickel anode (10$ on ebay).

Pluss 4-5V to the anode and minus to the parts. The current is about 100mA and plating time for small parts will be 2-3 hours and more time depending of the size of the parts.

I bught it all as a kit with anode, solvents and power supply. Before the plating start the parts are cleaned in a special solvent and after the nikkel bath I use a stop bath at the end of the process.

Can be smart to monitor the current so you know it’s all working and no bad connections.

If it’s all ok, and the current is flowing the part will turn gray after fiew minutes.

After some hours the part will be covered in nickel and is ready for polishing.

All steel parts has been nickel plated, the aluminium hub is only polished.

The entire process takes only few hours and I’m very pleased with the final results.

Assembly:

Parts for the speedometer gear:

Brake shoes:

The shiny springs are the old rusty ones in a better look.

Almost done:

Before and after:

Before and after

Return spring and clamping bolts:

Done:

The wheel mounted:

Mounting the fork

The fork was mounted according to the parts manual (GT380k)

Parts no can be found in the manual, go to the: Documents at my blog.

Resin print of 51553-3300:

I was missing some cushion parts. I only had one of the cushion for the headlamp bracket, the: 51553-3300

The resin 3D printer had some issues this time printing rubber resin, not sure why but still able to use the parts. I also tested the filament printer using flexible filament. Not 100%, but ok to be used.

Assembly of the front fork

Mount the damping rod (unknown part no) into the outer tube. Don’t forget the copper washer.

Oil seal:

Mount the inner tube and slide the oil seal down to the outer tube.

Next step can be difficult. Apply som grease around the seal, but it can be hard to drive the oil seal all the way down to the bottom. I did it “my way”

Since I have a lathe, I made a tool for the purpose.

With a plastic tube on top of the tool and a hammer it was easy to drive the seal all the way down.

Secure the oil seal with the circlip and the spacer.

Fork oil:

Install the fork spring and apply 210ml of oil. Screw on the top bolt and you are done 🙂

Don’ forget the drain screw at the bottom.

Mounting the fork boot:

This part turned out to be very difficult. The lower end of the boot was very stiff and not flexible at all, and looked too narrow to get around the outer tube.

Soften the boot with hot air helped, and by using some plastic stripes as a guid I was able to squeeze it on.

Inner tubes

Finally, after two years of nothing I’m back on track with the restoration process.

Luckily I did some research last time about what part to be fitted in the correct order.

I used images from my previous post about the topic and went a head and did the assembling of the inner tubes.

7 Steps:

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.

Cylinders

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 🙂

SRIS:

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.