VFR750-FL project bought

[Andy52]

Hello, I'm Andy from Warwickshire in the UK. In August I bought this 1990 VFR750 FL project, which was advertised locally on eBay. It was clearly an imported bike, with the speedometer in kilometres. A previous owner had started a cafe racer conversion, hacked the front wiring about then given up. I had a look at it, talked to the owner and it all seemed genuine so I put in a fairly low bid, not expecting to win. My idea was to put it on the road as cheaply as possible to see if I like it, then decide whether to sell or keep and improve it.

The seller had started sanding down the wheels and rear panels, bought it that lovely stainless steel radiator, a new fuel pump, air filter and various other bits which must have cost more than I paid him for it. He told me he had seen it running when he bought it, but it needed a new starter relay.

To my surprise, my bid won. I found that my pre-purchase checks had failed to spot the subtle damage to the fork stantions (looks like they have been hit with a hammer just above the dust covers), so I've bought some good replacement forks, the first un-planned expense. The starter relay was OK but the starter motor needed a new carbon brush and insulators. The wiring loom was such a mess that I fitted a second-hand replacement. The right-hand bar switch wiring had for some reason been cut and re-joined with crimped-on bullet connectors, all of which pulled off again.

The fuel tank was rusty inside, but this was easily cured with 20% phosphoric acid left in for an hour. David Silver helped with finding an equivalent replacement for the fuel tap 'O' ring. The next problem was a leak from the fuel tap itself, repaired using a kit from NRP Carbs. With a new battery and a generous squirt of carb cleaner the engine now started and idled nicely, but the carbs leaked fuel. I'm hoping that now they've had fuel in again the seals will swell up and stop leaking, but I'm leaving that problem until the weather improves and I can leave it outside for any spilled fuel to evapourate. I'm currently working on finishing the wiring and mounting the instruments and a round headlight using a cut-down front fairing bracket. Progress will be leisurely!

I've got two technical questions, and no doubt there will be more. I would be grateful for any help:

Amongst the bits missing are the screws needed to fix and connect the fuel and temp gauges in the instruments. Does anyone know what length and size these need to be? The holes in the back of the gauges are about 3mm diameter.

 

Another thing that my pre-purchase checks missed is that the engine is an RC35, meaning the bike is a Japanese home-market model. It does have 6 gears and if it's a bit down on top-end power I'm not bothered, but it might make re-sale a problem. One difference from the UK version is an extra orange/blue wire running from the CDU up to an original-looking bullet connector at the front end. This is missing from the replacement loom. Does anyone know what this wire would have been connected to? There is no unidentified terminal in the instrument panel.

[750]

At the risk of sounding negative. I'd cut your losses and break it for parts, hoping your bid was particularly low, that is.

 

The problem with making the 90-93 naked is those pesky fairing fins that otherwise meet the rear plastics - they look particularly ugly with any other subframe or fairing choice. The 94-97 doesn't have this issue and looks a lot better naked, as can be seen with Sebspeed's SF conversion, along with Apex Andy's.

[Terry]

The stray wire may be for a speed warning light in the dash, Japanese bikes were once upon a time required to have a red warning light on the dash that illuminated at 90 or 100km/hr IIRC. I've owned a couple of Japanese market bikes, including my current VTR1000F, that one had an ignition limited speed of 180km/hr driven from the speedo, and it is possible that your VFR had something similar, which would require a connection back from the speedo to the ignition. I can report (from a "private" road test) that defeating the 180km/hr limiter was as simple as disconnecting a green/pink single wire at the speedo and had no unintended consequences for the ignition.

[mobikie]

I have a similar bike. I have attached a photo of the wiring behind the instruments.

They are excellent bikes. I love mine.

[slovcan]

Honda used to put an open "accessory" lead behind the fairing or in the headlight bucket of its older bikes - V65 Magna & Sabre, for example. Maybe it's this?

 

Cheers,

Glenn

[JZH]

The screws for the fuel and temp gauges are M3 x 21 pan heads.

 

The J-spec bikes have JDM-only instrument panels and wiring looms.  The pictures in the Parts Catalogues (I have them for all markets) aren't always exhaustively detailed, but it appears that there was an extra wire on the main wiring harness as well as on the instrument panel loom.  The J-spec instrument panel loom shows an unidentified object in the region of the upper LHS corner of the panel, which corresponds with the location of the speedometer, but it is otherwise not described at all.  There was also an extra plastic plug on the J-spec panel:

I know what it is because the J-spec NC30 also had one just like this, and it was used to (sort of) seal an opening in the back of the instrument panel, through which the speed restriction circuit board's wires passed.  In any case, the extra wire is most likely either a speed warning light or a speed restrictor, and I don't believe the J-spec RC36s were speed restricted (they were definitely power restricted--to 77PS), so that leaves a warning light.  Certain NC30s also had such lights, and interestingly it turns out that this was a requirement in only certain prefectures in Japan... 

 

Ciao,

[Andy52]

Thanks for all your replies, especially 'JZH' for answering both my questions! I don't agree with '750' about the suitability of the 90-93 bikes for customisation though, and I intend to carry on with the project. I realise that my taste in bikes is a bit odd, but I customise bikes for fun not profit. The last bike I completed and sold was a naked Pan European, called ugly by many, but someone liked it enough to buy it!

 

[JZH]

On 12/21/2017 at 3:54 PM, Andy52 said:

Thanks for all your replies, especially 'JZH' for answering both my questions! I don't agree with '750' about the suitability of the 90-93 bikes for customisation though, and I intend to carry on with the project. I realise that my taste in bikes is a bit odd, but I customise bikes for fun not profit. The last bike I completed and sold was a naked Pan European, called ugly by many, but someone liked it enough to buy it!

 

 

That looks...surprisingly good!  Good luck with your current project.

 

Ciao,

[bigmalcy]

Hi Andy

I had a JDM RC36 many years ago... she died in the Scottish Borders one lovely Autumn evening in 2002.

 

Before she died, I replaced the JDM clocks with UK spec clocks and I remember that there was an extra wire in the loom that didn't have anywhere to connect to after the new clocks were installed.  I think this is probably the same wire you have found.

 

I also found that after the clocks swap the bike wouldn't go over 5000rpm when in gear (fine when out of gear)... so i connected that spare loom wire to a +ve feed and that solved the problem.  I never did find out what that wire was, but i suspected it was a speed limiter: i surmised that in its original configuration, the +ve feed was provided to this wire from a circuit in the original clocks, but the +ve feed would then be cut when the bike hit the speed limit, cutting ignition and limiting speed.  

 

Hope this helps!