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The idiot’s guide to installing a fireblade engine in a Fury

When I tell people I drive a plastic car with a 900cc engine, they automatically think Robin Reliant. How wrong they are!

This is my experience of replacing my old Xflow engine in my Sylva Fury with a marvellous Honda CBR900RR (aka Fireblade) engine. This is not a cheap or easy option but you will get an exceptional car that will blow your mind every time you drive it. It should also be reliable, low maintenance, economical (when you aren’t thrashing it), it takes unleaded and you even save 50 quid on your car tax! In addition, the reduced weight of the car will have beneficial effects on braking and handling. The great thing about this engine is that all the ‘tuning’ comes as standard. You get a 13,000-rpm red line, performance carbs, a 6-speed close ratio sequential gearbox with lightning up-changes and an ultra-light flywheel. It’s fairly quiet at low revs but give it some stick and it sounds BRILLIANT!

The following instructions are by no means definitive; it’s just how I did it. It’s also not in the order I did it in.


What you need:

Obviously you’ll need a fireblade ‘package’, mine was a 2000 miler and cost 1500 + VAT. If you shop around, you may get a better price. Make sure the engine number has not been filed off. Also make sure it includes all ancillaries, carbs, airbox (optional), wiring loom, ECU and regulator, engine bolts, fuel pump and clutch/throttle cables. Be aware that 1998 onwards engines come with a built in immobiliser which will require you to use the original keyfob or it won’t start. Mine was a 1997 ‘V’ engine. Much earlier engines are slightly smaller (by about 30cc).

Read through the rest of this account and see what else you need to buy – you may decide to do things differently from me. There is a package to come from Fisher including the engine mounts, propshaft adapter, exhaust manifold and gear linkage. This lot totals about 450.


Prop adapter

I loaded the engine onto my winch without any problems; it’s ever so easy to deal with compared to a big old iron car lump. With the engine dangling over the car I took the opportunity to pop the prop flange onto the output sprocket – pop!



I then attached the engine mounts. These ought to fit on without any drama but with mine, all 3 of them needed butchering because several of the holes were slightly misaligned. You will need to drill 10mm holes through parts of the casting, these are for the nearside bolts on the front and rear engine mounts. You’ll need two additional M10 bolts (+ nuts) here. Don’t lose any of the bolts that come with the engine because although they are metric, they are unusual sizes with fine-threads. The two long bolts on the offside mount are too long for our purposes, slot a bit of metal tube over the ends in order to get your nuts in the right place (always important).

First cut away any residue of the old engine mounts - I had two upright flanges welded to the chassis. Although the new mounts attach in a similar way, they are at a different angle so they cannot be reused. Grind the area nice and flat and paint it. Also paint the U shaped brackets on the engine mounts too, these aren’t plated unlike the rest of mounts. Next lower the engine to work out where to put the new mounts. It is normal for the engine to be heavily canted over to the nearside. Getting the engine at the right angle is crucial. I used a combination of a winch and a jack in different positions.


Fore-Aft Location

Move the engine back as far as it will go so that the rear mount is touching the scuttle tube – at right angles to it, mine was actually a little bit misaligned in the end, probably due to the cutting/shutting I had to do on the mounts.



Make sure the two side mounts are resting on the flat plate on the chassis where the old mounts were. I took off the U shaped brackets and measured how large the gap underneath the bush should be and padded out the mounting plate with some packing of roughly this thickness. Otherwise the lower bolt gets in the way.


Lateral Location

The engine needs to be pushed quite a long way to the nearside. The prop should enter the tunnel as straight as possible but you should expect a slight angle. This won’t be a problem as the prop is a two-piece item.

I then marked the position of the offside mount, drilled the hole for it and fixed it in place. I did the same for the nearside mount, always checking that the rear mount was still in contact with the scuttle tube. The nearside mount had to be packed with large 10mm ‘repair’ washers because otherwise the oil filter was pressing against the chassis. It was also too close to a tube to get the nut onto the bolt so I welded it. Next, mark the chassis for the rear mount; I did this by dabbing some paint on the bolt end to see where it was touching the chassis. I had to buy a longer bolt for this too; the one supplied was too short; you need M12 x 80.


Gear linkage

Stick your car on axle stands. Make sure you have the gear selector arm from the ‘blade. Cut the rose joint off it and drill a 6mm hole through the centre of the stub so you can join the short link from Fisher. The long bar on the front part of the linkage straddles the transmission tunnel. All you need to do is make sure all four holes are on the chassis and rivet the assembly on to the underside of the front chassis rail. Do the same for the top mounting point. Bolt the short link onto the bottom of the actuator arm and onto the ‘blade selector arm. Don’t worry about adjustment yet, the short link is adjustable and you can also change the position of the ‘blade selector arm.

Next, I attached the long link to the gearlever. I found this was too long for where I wanted the gearlever to emerge (I wanted it where the old lever from the Sierra box was). So I had to shorten it by 93mm. I cut this length out of the middle used a tube as a sleeve to go over the join and riveted this on. Offer the gearlever up to the driver’s side bottom chassis rail. This needs to pivot so I found a little piece of metal tube and passed it through the bottom hole and attached it to the chassis with a big-head rivet. Finally, add the lever guide by taking the tunnel top off so you have room to drill the rivet holes.



Fuel pump

The Fireblade does not have a fuel pump – it’s gravity fed. I actually got a fuel pump with the kit but it wasn’t until I failed to find a plug on the loom for it that I realised it was a separate item. I used an inch wide aluminium strip to rivet it to the chassis tube opposite the carbs. Don’t mix up the carb breather pipes with the fuel pipes! The fuel pipes come out the bottom of the carbs, I needed to buy a T piece to join them then attached them to the pump. You’ll need some hose-clips because the weedy ‘blade ones might not be enough for the pressure the pump generates. The pump is wired to ground and to ignition live (not permanent live). A fuel filter is also a good idea, I already had one.


Clutch cable

The engine end can be left unmodified. Put the adjuster nut towards the top of its range – it’s unlikely you’ll want it more slack. At the other end, I bent out the curve in a vice. In order to hold the cable outer to the bulkhead in front of the pedal, I made up a short length of tube welded onto a washer and rivetted this to the bulkhead.

The clutch actuator arm on the gearbox is easy to push a certain distance with your finger, this is just free play. When it hits a brick wall at about the 9 O’clock position (engine viewed from offside), that is where the clutch travel starts. I pulled the clutch cable as far as it would go to take up the free play in the lever and measured the distance between the pedal spindle (a 6mm bolt on the Escort pedals) and the end of the cable. I then cut a strip of stainless steel to make a hook with a slot at one end, bent right back to grip the node at the end of the cable. The other end of the metal strip then needs a 6mm hole drilled to fit onto the pedal.


Throttle cable

There are two cables. One opens the throttle; the other pulls it closed. Ignore the latter, just tuck it away somewhere where it won’t snag. I have an old style tall pedal box. The cable has to enter the pedal box from the left side otherwise it’s not long enough (it has a 90 degree elbow anyway). Connect it to your throttle pedal and use the adjustment at the engine end to fine-tune it.


Choke cable

My existing one was too short because it has to bend round to mount onto the front of the carbs. I bought another. I think the blade had an annoying node welded onto the cable so you’ve got to get your car choke cable to fasten somehow. I used a bolt and a couple of washers to clamp the cable. This seems to work OK.



The easy way is to buy a stainless manifold from Fisher for 150ish and use your existing silencer. I tried to adapt a Fireblade system but unless you are an expert welder and can make airtight joins without the metal protruding into the primary pipe, chances are you are on to a whole load of grief. I therefore bought a Fisher special and used the Fireblade back box and bought a piece of straight pipe from Custom Chrome to extend it. If you are going to use the blade box then you need to weld on the flange that attaches it to the end of the exhaust pipe. Apparently aftermarket blade boxes are less restrictive and sound better. The manifold needed a little bit of fettling inside the inlet ports, there was a bit of lumpy weld that was making them narrower than they should be. I ground it down with drill mounted stones, the inside diameter should be around 31mm.

The mounting point on the blade silencer could be used horizontally with a vertical bolt holding it on. The exhaust must be held firmly or it could crack in use. I only used one mount made from two small exhaust bobbins, one above the other and a small steel bracket. I think one will be sufficient because it is fairly near the front of the blade silencer so that’s OK. The blade silencer does not have an elbow in it to exit the pod sideways so I fixed a bit of oversized pipe on. While I had the pod off, I also took the opportunity to seal off the hole on the underside of the bodywork just in front of the doors. This lets steam in if water hits the exhaust. Make sure the exhaust is well ventilated, I have a hole in the front of my left-hand pod and have glued some aluminium foil to floor of the pod near the manifold. DO NOT use exhaust wrap.



I reused my old Xflow radiator, this presented some problems with hose diameters and the lack of a location for the fan-switch. The top rad hose connects to the front of the engine and the bottom goes to the rear. I had to buy some extra bits of hose the same diameter as the other bike hoses. I overcame the difference in hose sizes by attaching a bit of the old Xflow hose to the radiator and pushing the bike hose inside it – they fit snugly. With a piece of metal inside the bike hose, you can clamp them together. The bike header tank is not required. The bleed pipe can be cut short and sealed off with a bolt and a hose clip. Don’t cut it too short because it can be handy for bleeding the system.

I cut a hole in the radiator and glued the fan switch into it, which is a bit of a nasty bodge. What I should have done is choose a fan switch that has a sensible thread size. You can then cut a hole in the radiator and weld a nut to it so you can screw the fan switch in.

To bleed the system, I took off the radiator cap and opened the bleed point at the thermostat housing. Give the engine a few revs every now and then to push air through and remember to keep the coolant topped up. When water starts dripping out, close the system but leave the engine running to warm up to operating temperature. Allow cooling then carefully pour some water into the bleed point and check the level under the rad cap again.


Breather pipes

Since I had to doctor the airbox, I just let my crank and cam cover breather pipes roam free as nature intended. They are unlikely to spit oil but you can always add a (vented) collector just in case.



Oil and filter

Since you may not know the history of the engine, an oil change is a must. Use the oil recommended in the Haynes manual and change it every 2-4k miles (not 8k as it says in the manual). Bike engines are engineered like Swiss watches. They will give good mileage if treated well and only revved hard when nice and warm. If not, they will soon resemble Swiss cheese…!



If you are going to use the bike binnacle intact, you’ll need a new dashboard blank. I bought a sheet of turned aluminium from Europa (35) – looks the business. I retained my Smiths fuel gauge from my previous setup because the bike doesn’t have one. The binnacle is an awkward size, I ended up having the revcounter poking up above the dash top by an inch or so. Remove the foam surround and cut off the three plastic turrets. The top two turrets can be used as mounting points, I drilled 6mm holes in them.

Next the tricky bit – make a cardboard template with the three dials and the warning lights poking through. Use this to mark the dash so you accurately cut out 3 round holes and an oblong one. Be aware of the position of the chassis tube that supports the dash. The binnacle is then pushed through from the rear and the mounting holes are drilled. I used allen-key head stainless bolts to hold it on. The dash top then needs trimming around the revcounter.

The bike speedo cannot easily be reused. It has a sensor in an awkward place and is probably wrongly calibrated for the car’s wheel size and differential ratio. I bought a Sigma 700 bike computer which reads speed very accurately, records mileage and has more advanced functions too like average speed and top speed (heh heh). It also allows you to re-enter your mileage if the battery runs out. The sensor fits on the front wheel. You could always find an equivalent size electric speedo to fit in the hole in the binnacle.

The bike computer requires a little curved aluminium bracket to be rivetted onto the dash for it to stick onto. It also requires another little hole to pass the wires through. The wires will need extending forwards to the front offside wheel. I glued the magnet to the wheel using Liquid Metal and made a right-angle aluminium bracket for the sensor, this was then attached to one of the brake caliper bolts.

Attach the instrument multiplug up with the rest of the bike loom. Snip out the turn and high-beam warning lights to join them to your existing wiring. The ‘stand’ warning light could be used for a handbrake/brake fluid warning light if you so desire. Identify which is the illumination feed for the instrument pod and wire it into your main loom.


The reverse gear problem

The most frequently used solution to date is the Reverseron gearbox which is available from Formula 27 Cars (580 - ouch). Fisher Sportscars are working in conjunction with BGH Geartech to produce something similar for a lower price – it is supposed to be stronger too.

I want a reverse gear but I got the car on the road before getting one. I shall hopefully develop a cheap electric reverse using a starter motor. If I do then I’ll write another tome like this one. If not, all I need to do is buy the new BGH reverser box and have my propshaft shortened.



Measure up for the prop. I ordered mine from Fisher (185). You just measure from flange to flange and give them this measurement. Bolt the end with the sliding sleeve to the diff and the other end to the engine. It’s a 2-piece item and you’ll need to make sure you have Fisher’s centre bearing support and the right bolts to fix it to the propshaft and to the car. You’ll need to take the side or top off the transmission tunnel to have access to the bolts. I ran into trouble because I had shortened the gear linkage and the bottom pivot was now level with the place where the central bearing was to join to the chassis. The bearing support was also too wide so I had to grind off the ends and re-drill the mounting holes. This was actually helpful because I could trial fit the support to the prop and then drill the holes from the underside straight through the chassis and the support. I found that the support bracket was right next to a chassis tube for the handbrake so it had to go in at a slight angle and the slots on the propshaft centre bearing had to be filed to get it all to fit. The gearlinkage had to be shortened again to cope with the new pivot location.



I have heard several different stories about this but after speaking to a chap who tunes Fireblades for racing, I decided to keep the Fireblade’s airbox. He said that ALL the racing engines he’s seen use the airbox rather than aftermarket foam filters. The carburettors are designed to work with this box so anything else is going cause problems with flat spots.

It’s not easy to fit the airbox under the bonnet, even in my car that has a large central bulge. I ended up modifying it quite a bit whilst trying to retain the original volume inside the secondary chamber. Turn the airbox upside down so only a corner is protruding upwards and fouling the bonnet. Then cut the face that has the four holes in it for the trumpets. Cut it along 3 sides of a rectangle so that the box can flop down and clear the bonnet. Then use aluminium, self-tapping screws and sealant to reshape the box. Leave as much room around the trumpet entrances as you can.

Other people have used short lengths of flexible pipe running from the trumpets to the box. I favour my solution because the trumpets are inside a volume that is open on all sides.

This should work fine as it is but you can fiddle with it some more and achieve results. The engine is designed to run lean at certain rpm to comply with emissions regulations. Fitting a ‘dynojet’ kit can help alleviate these flat spots and can also compensate for the fitment of a K+N filter element and free flowing exhausts.


Final drive

The Fireblade has a reduction gear between the engine and the gearbox of 1.52 : 1 so when you include a car’s final drive, you can see that the gearing is quite short. It’s about 10mph per 1000rpm in 6th gear with my 3.89 differential. The effective differential is 1.52 x 3.89 = 5.91. I would almost certainly hit the redline before I hit my maximum speed. Mark Fisher thinks the 3.89 is perfect for hillclimb cars and I think it is also good for ‘weekend warrior’ type drivers. However, mine is going to be more of a sports-tourer so I shall probably fit a 3.54 diff. The best advice is to drive the car for a couple of months before deciding whether you like your current differential or not.


Coil packs

Both the leads and the cylinders are marked so simply plug them into the correct sparkies. The units themselves are then mounted fore and aft of the engine. You need to make brackets using strips of metal with extra bracing to hold them rigid. The front one rivets onto the front engine mount. The rear one attaches onto the end of the rear engine mount bolt.



The blade loom is easy to install. You can integrate it with an existing one like I did or you might even be able to use it as your only loom. Note that various wires would need extending and it doesn’t have a fog, reverse light or charge warning light.

I bought a Haynes manual expressly for this job (20) - it has superb colour diagrams. Firstly, I scanned and printed the one for my engine (1997 – ‘V’) it so I could scribble on it. A photocopy will obviously not retain the colours. Here is a general method of tackling this job:

  • Ignition-live from ignition to red/blue wire on bike ignition switch plug.
  • Ignition-live also needs to connect to the fuel pump.
  • Starter motor trigger to yellow/red.
  • Permanent-live from battery (via the blade 30A mini fuse box)
  • Loom earth to chassis (this didn’t quite reach in my case).
  • Alternator earth to chassis
  • If you have an ignition cut-off switch, wire that to where the bike’s was. Else just join the wires together.
  • The plug that went to the ‘sidestand switch’ on the bike must be wired closed so that the ECU thinks its permanently in the up position. Otherwise the engine cuts when you engage a gear.

Now you can test fire the engine! Note that on later models you must be in neutral before the starter motor will fire. If you don’t like this then jump a wire across the connectors for both the side-stand and clutch switches. If nothing happens, the most obvious checks are that the fuel pump is pumping and the sparkies are sparking. Now finalise the positions of all the wires and boxes, you’ll need tie wraps and self-tapping screws for this. Note that the regulator will get hot in use and should be attached to a metal bulkhead ideally. I ended up having a strip of aluminium under it that will hopefully carry the heat away effectively.



You need 130lb springs (about 10 each) all round, dampers on full soft all round. Most Furys already have 130s at the rear. Tyre pressures at between 16 and 18psi all round. These settings are off the Fisher hillclimb car but if you want to argue with that…

Also, be aware that the car is ever so slightly tail heavy now.


Final drive

A mistake people commonly make is that they think the fireblade-powered car is going massively over geared. This is not the case because there is a reduction gear between the engine and the gearbox of 1.52 : 1. So in actual fact the gearing is quite short. With my 3.89 differential, the effective differential is 1.52 x 3.89 = 5.91. I would probably hit the redline (13k) before I hit my maximum speed. This is down to personal preference. I haven’t had it long enough yet but I might choose to fit a 3.5 diff to get better cruising speeds and spread those super-close ratios out a bit.


Other guff

Don’t forget to tell your insurance company. My premium jumped up a bit which is annoying but it’s all worth it – trust me!

Also get your V5 amended by the DVLA. If you don’t do this, you won’t be able to persuade your post office to give you reduced road tax. The DVLA are a right pain in the arse, they refuse to believe that it’s a sub 1100cc engine without documentary evidence. I ended up sending them my receipt for the engine, which had the engine number on it. I also sent them two photocopies from the Haynes manual – one matched the engine number to the year and vehicle type, the other showed that that particular year vehicle had a 919cc engine.

Don’t forget the beast takes unleaded. Oh, and go easy when you first start to drive it. The combination of super-sensitive throttle response, sequential gears and ultra light clutch was certainly a lot for me to get used to – have fun!

    Nick Walczak



March 2001 

Nick no longer owns the car.  It is now owned by Francois Lorho.
You can see pictures of the car on his funky website: