New 2008 Mods on Doc's FJ Racer

Doc's FJ Racer mods for the 2008 season

After getting 2nd in the Forgotten Era racing in the Wirral 100 club (2007) there were still need for improvements so some modifications were needed to the ‘Racing Fudge’ if I want to beat the likes of Dennis on his Yamaha ExUp and Mike on the one off race bike ‘Westlake’.
Engine;
So the first mod recommended by my Jerry Burgess friend ‘Gordon’ was to fit Flatslide carbs. These were imported from the USA via the official Keihin UK importers as we found there ware only TWO sets in the world left. They were fitted before I did any work on the bike and was sent straight down to the Dyno.
The result was a 143 bhp at the top end, which was a slight increase of only 3 bhp (though he said it was running very rich and correct fueling may bring some more power).
Dyno man Tim recommended taking the air filter off which then made another 3bhp.
Problem is, its always hard to increase horse power and the cost goes up massively per hp so this is the last expensive engine mod I plan. I pulled the engine barrels off to check pistons etc and found them all in perfect condition even after a seasons hard use. On its rebuild I fitted some APE heavy duty valve springs and HD cylinder studs as the head gasket was just starting to leak due the OE (90k miles) valves and studs were past there best.
The final mod was inspired by the Legend Cars that use the FJ motor. They have auxiliary oil feeds to the cams that run from the oil supply from the cooler take off. My only problem with this idea was they fed it to the right hand side of the cams, seeing as this is the same side as the OE supply, I couldn’t see the advantage. So I designed the oil supply to run to the left hand side of the cam, so allowing twin oil delivery from both ends of the cams for quicker and greater delivery of oil to the top end.

Footrests;
The first job was to modify the footrest hanger location. I have OE Gixer pegs mounted onto an alloy plate. I mounted these pegs direct to the frame by welding nuts to the outer frame, this meant the pegs came in approx 10mm so allowing greater clearance when cornering.

Frame;
The welding had made the frame unsightly plus the 24 year old paint work was flaking, so it seemed a good idea the get the frame powered coated (remember looking good is important!), this meant the complete strip down of the bike.
A local company coated it standard silver for only 70 pounds.Fuel Tank;The plan was to build a remote fuel tank under the seat. The reasoning was if I could hollow out the OE fuel tank it would allow the heat from the engine (due to the high temperatures created by the high 12-1 compression ratio pistons) to escape through some vents, .
The tank only needed to hold around 4 ltrs as the race is only held over 5-6 laps, even on a 20min track day it only uses 3-4 ltrs. Having no welding equipment I resorted to fabricating the tank out of sheet Aluminum using knowledge from my days in the RAF. Having no solid rivets available I resorted to using self tapping screws and pop rivets.
To make a seal I obtained some tank sealer called PRC from some RAF friends. For the fuel cap a used a Motrax keyless replacement cap was modified to suit. The tap was a quick self releasing coupling. The result was a 7 ltrs Ali tank under the seat shaped to clear the rear wheel and to locate the Gel battery. Now lets hope it doesn’t leak!
Using an old FJ1100 tank I cut away vents in four locations to allow the heat of the engine to escape. A s/s grill was spot welded to cover each of the holes to make it look tidy.

Respray;
The body work was tatty having come off the bike a few times so I decided to respray the kit in Yamaha’s racing colour (Kenny Roberts) yellow, white and black.
This should at least give people a chance of to spotting me. Liam’s FJ12 is standard red/white, Giles and Steve’s FJ1100 are standard blue/white. A local friend Biddy did the respray for a bargain price of 200 pounds, this included the extra OE non modified tank.Oil Cooler;
To allow more air to get to the engine to aid cooling I re-positioned the cooler from in front of the engine to the front of the fairing where the headlamp is normally situated. The 10 row was replaced with a 16 row, but to fit the hole of the headlamp, the width of the cooler was reduced, so making its surface area small and less efficient. Which is a shame but its at least twice the area of the OE cooler.
No Alternator;
To save weight the alternator was removed and a special blank was purchased from the USA. To aid starting I wired up an electrical coupling that allows a direct connection to a charger/starter unit which can be removed once the engine is running.
Crankcase vent;
The engine filler cap was replaced with a venting system to aid the release of crankcase pressure due to the movement of the pistons. Both this and the normal crankcase vent are attached to a hand built breather catch tank.Conclusion;
The standard weight of an FJ1100 is approx 250kg. The 2007 racer weighted in at 210kg, with the new 2008 mods that was reduced to 198kg fully wet including 6 ltrs of fuel. The power is slightly up to 143-146 bhp at the rear wheel. Here’s to racing in 2008, lets hope the bike and I are up to taking 1st position at the end of the year. Any support in the race series is welcome, so hopefully you may find time to visit us at Oulton Park or Anglesey, taking on the best from both the Forgotten Era and the Power Bikes race (used to practice in and piss off GSXR1000 and R1’s).

Thanks to all those who have wrote in or emailed with your support for both me and the team.

Doc

F J Racer 016
good10
full04
full03
F J Racer 028
front09
engine rear
engine cam mod
good9
side07
fuel tank l

You are viewing the text version of this site.

To view the full version please install the Adobe Flash Player and ensure your web browser has JavaScript enabled.

Need help? check the requirements page.


Get Flash Player