Suzuki GT380B

First Registered in the UK in September 1978

Picture below is as I got the bike in 2019, which has been owned for some years by a friend of mine who no longer rode it.

Picture taken April 2020

A good solid machine albeit a bit tired and been off the road parked up since 2013 and not started in several years. One thing he did warn me about was that it was very smoke and suspected it either needed a rebore or the pump needed sorting.

1978 Model B, but it's 40 years old and a few bits not exactly per that model's spec, such as tank and panels, rear light, front mudguard and various other bits. Doesn't take away that it is in pretty good condition plus I'd seen this bike on the road many times before so sort of know a bit about its history for a few years back.

Bike moved into garage late April 2020 to begin the work...

First pass is to take main parts off, check status and refresh or replace as needed.

- Took front end off, checked, replaced old rusty nuts and bolts with stainless or zinced parts.

- Removed Exhausts and stuck cleaner down to flush out what seemed to be an alarmingly large amount of black sludge - left these standing for several days to try to get most of this stuff out.

- Swapped out both front an back wheels initially for a set of Alloys I had in the shed. I will fit a better set of spoke wheel later.

- Electrics all seemed to check out fine, including the charging unit. Did spot the points and coils are Nippon Denso and the Alternator setup is Kokusan, but seems to be working.

- Took off headlight and fork shrouds and replaced shell and shrouds with newly powder coated items freshly back from CTC in Maldon. Alternate Chrome rim and glass fitted and also alternate chrome and rubber parts fitted for the shrouds.

- Took off Airbox and Carbs. Existing carbs started ok, but seemed to have some issues and definitely needed an internal clean at the very least. Used the bike to test some newly rebuild sets of carbs and chose to use one of those sets going forward.

- Checked compression and seemed reasonable but when I took the barrels off the pistons seemed to show signs of blow by. Therefore replaced set of Barrels with a newly blasted set which had been honed and a set of new Pistons, Rings, Wrist Pins, Small Ends etc. plus new top end and exhaust gaskettes. Also fitted newly blasted Cylinder Head and new Nut and Washers to Barrels and Head as the old head had some fin damage.

 

Fresher look and better compression

 

- Refitted the exhaust and replaced numerous nuts, bolts and washers with new zinc or stainless items.

- Bike had been smoking badly so needed to check. Had a look at the Oil pump, spotted a leak in the pipework and replaced with NOS pipe and while there also fitted set of new Oil seals and bled the setup - bled the pump when I started the engine to remove any air bubbles

- Airbox Snorkel was missing, but I know people used to do this to get more air into the system so no biggy

- Fitted alternate carbs plus new rubbers and clips to the alternate set of Barrels + head and new plugs. Balanced the Oil pump the carbs and started the engine - all seemed to go smoothly and seemed crisp, even using the existing points and condenser setup.

- New Tacho, Speedo and Clutch cables fitted

- Replaced Rear Light with the correct Model B fitment unit

- Replaced rear suspension nuts with stainless

- Fitted new Horn

- Took off Front Brake, checked and cleaned. Already had aftermarket pipework which all seemed good. These brakes are crap compared to modern stuff, but it's as reasonable as you could expect from something 40+ years old

- Replaced the Front Mudguard, which was not original and damaged with a Suzuki 380 item. I know it's not the right model, but it's better than what was there for now.

- New Rear Brake Light Switch fitted

- Replaced Petrol Tap

Some of the work was to resolve a few issues the bike had or replaced older more worn pieces with better component and others were cosmetic only.

 

Took the bike out at various stages to check things and the start to run-in the engine. Covered around 120 miles and all good..

Second pass was to dial in on some other bits...

- Bike had still been generating a lot of smoke despite new O rings, pipework and setting up. Therefore replaced the pump unit.

- New Chain and Sprockets fitted.

- Handlebar Switches taken apart, checked & cleaned up.

- New Clutch & Brake Levers

- New Mirrors

- New Front Footrest rubbers & new Pillion pegs

- New Handlebars

- Replaced Side Panels with black ones per model

- Fitted Spoke wheels, which were built by Hagon some years back and fitted with stainless spokes.

 

As at June 2020

February 2021

2020 was a strange year and as a result of all the restrictions and lockdowns I only managed to cover around 280 miles on the bike and as it had a new top end then most of tht was sub 5k RPM.It ran really weel.

Initial plan was to keep this one and do a third stage whereby I 'd strip it all down and have the frame and other parts repainted. I did get as far as having a replacement tank professionally painted in the correct blue and grahocs for the B model but that's as far as I got.

A member of GT380 forum was looking for a decent bike and realising I really needed to free some space in the garage I agreed to sell him the bike so he can take it to the next level.

Updated Dec 2021