Awesome 1986 GSXR750 Rebuild Project

The Suzuki GSXR750 restoration project started when I decided that I needed a winter bike to replace my Yamaha FJ1100, which was still serviceable but becoming less reliable and would require a large cash injection to raise to a standard I would be happy with. Instead I decided to look for an early GSXR750 which could be the basis of a restoration project to utilise some of my spare parts, which I’ve kept for the GSXR1100s over a period of ten years.

I also had access to a pool of GSXR spares with a friend, who bought my second GSXR1100 from me several years ago, and we help each other with maintenance and spares. My GSXR1100 is heavily modified with many parts from later models, and performance parts which I’ve added over the years. The modifications have improved the bike, and also added to the spare parts tally.

The base for Project GSXR750 started with an ebay purchase of a GSXR750 1986 non-UK model in May 2013 for £700. The bike was advertised as a non-runner, and the majority of the parts were included to rebuild the bike. The bike also came with  a few boxes of assorted spares for other makes and models of bikes.

The bike was bought on the weight of information within the advert and the pictures.  On collection of the bike it was clear that the bike had been subjected to some rather ham fisted mechanics, but a good starting point for a project.

Disassembling the GSXR750

The first job was start breaking down the bike to understand what needed to be replaced and what was missing. The majority of the rear and lower bodywork was in good order, but the front sections were damaged beyond economical repair. The standard rear suspension was leaking, and not a serviceable part so replaced by a new Hagon unit.

The engine was not seized but would not start, and smelt heavily of fuel so the carburettors were removed for inspection and repair. The inspection revealed that a previous owner had tried to repair the accelerator pumps with biro springs, and one of the floats had broken. Fortunately the flatslide (VM29ss) 750 carburettors share the same floats as the early GSXR1100, so I utilised a spare set from the parts from the spares pool.

The carburettors also went through several cycles in the ultrasonic cleaner to remove any debris before replacing any badly worn parts, including new O-rings securing the float valve seats which also contributed to the over fuelling.  The bike was fitted with the NEAS electronic anti-dive controller usually found on early GSXR750s but fitted with the standard GSXR750 mechanical anti-dive front forks.

During closer inspection of the front suspension it was identified that one of the front stations was bent and the lower top yoke was bent, probably the outcome of a crash. Fortunately I had a spare set of early GSXR1100 front forks and yokes, so the replacement forks were rebuilt using Hyperpro progressive springs and a custom made blanking plate over the anti-dive valve.

Painting and powder coating

Everything that could be powder coated was blasted and coated to protect the metal form the weather throughout the winter, including a set of later GSXR wheels from the spares pool to replace the original 18 inch wheels. I decided to use Hamerite Smooth on the engine cases to reduce costs, and get a finish closer to the original engine colour without having to repaint the entire engine. I thought the overall result using Hamerite was excellent and recommend over standard aerosols when painting engine cases.

Unfortunately the original Suzuki exhausted supplied with the bike was rotten and beyond repair so a used Micron full system was provided by a friend in exchange for some parts (thanks Lee). The engine valve clearances were checked and the engine given a quick health check by Rob at Mistral Performance Engineering prior to reassembly.

Reassembly to rolling chassis is a fairly quick process, with the majority of the time being taken to ensure bearings and bushes are correctly installed, and the correct bolts installed and torqued correctly. With the rolling chassis in place I started to focus on setting-up the engine and checking the electrical system. You may also want to check out some useful information for workshop tools which I generally use for maintenance and restoration projects.

The flatslide carburettors didn’t require any balance adjustment, and minimal adjustment to the pilot screws to accommodate the aftermarket K&N air filter. The brake calipers, clutch slave and reservoirs were overhauled with new seals to ensure reliability after an initial test run of the engine indicated that fluids were not returning to the reservoirs correctly.

I decided to keep the original paint scheme, and use spare panels to  replace the damaged panels provided with the bike. I wasn’t looking for a show winning paint finish so I asked a local company to prepare and spray all the panels with a gloss black, and I applied the decals prior to sealing with a final clear coat.  The gold decals are not easily available but I managed to track down a full set from RD Decals.

After some niggling problems were solved during the first few test runs the bike ran well throughout winter 2013, and I also installed heated grips and a satnav charger/mount. The bike recently broke down due to a signal generator failure, which I’m currently fixing whilst serving the bike for winter 2014. The Suzuki GSXR750 probably wasn’t designed as a bike for all seasons but is still great fun on the back roads if you find a good one or decided to take on a barn find 🙂 Special thanks to Simon Stephens who was the hidden helper during rebuild.

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Ride safe,
Al (Barnfindmotorcycle.com)