peterb

When you get new bearings and steel bushes, assemble with a lot of waterproof grease and fit an extra O ring to each of the 6 bushes, such that a tight fitting O ring comes up against the shoulder part of the bush. After 1 1/2 yrs use in wet conditions, there is no wear. Getting the last bolt undone is a nuisance, but with the rear brake lever removed, you can just to say get the short end of an allen key in at the bolt, been meaning to grind one a bit shorter to help. Also managed to get a 1/2" drive Torx bit to fit the socket screw head (T45 I think) which helps too.I don't have any 1/2" hex drives. Pretty sure that the new 2018 rocker has a different geometry to the older bikes. I rode a 2018 model which feels like it sits up a tad higher at the back and is easier to bounce the back wheel around than on my Ice 300. Bye, Peter B.

Try Nigel Birkett for parts. Bye, Peter B.

Those old Scorpa's are difficult to work on. I replaced a piston on one about 12 years ago with the motor still in the frame, the head did come off ok, I can't remember it being a problem, may have to rotate it to another position to remove. Perhaps the shock had to be removed. Getting the cylinder off was a problem in as much that you needed to raise the cylinder, and rotate the crank to allow access to the gudgeon pin. Stuff some clean rag into the crank case, remove a piston circlip and tap out the pin completely. Leave the piston in the cylinder and lower the con-rod to BDC, then wriggle out the cylinder with the piston inside, or if you just want to replace the little end, then leave the cylinder with piston hanging above the motor, get a friend to hold those parts. Good luck, PeterB.

Probably not a good move to change to DOT 5.1 for the clutch as the system uses mineral oil for the hydraulic fluid, I don't believe DOT 5.1 is compatible and would swell the master cylinder seals. The slave cylinder O rings are teflon coated so would just need a clean. Best to use a dab of tacky grease on the slave piston to hold the thrust bearing and washer in place when re-assembling. There is usually a fair amount of swarf behind the clutch belleville washer (spring) so I wouldn't take it for granted that the other needle roller has been minced. Have an even closer look at the kickstart idler gear and clutch ring gear, it doesn't take much at all to damage one of the gear teeth and make a clunking noise, though if not too bad, you can use slip stones to ease back the damage. Would pay to strip the motor and look for the lost needle, then at the same time replace all of the primary and secondary shaft bearings while stripped out, they don't cost much. Definitely replace the 2 sets of 1/2 needle rollers as these wear quickly and can cause more problems. Only real special tool you'd need is a flywheel puller. Bye, Peter B.

The bleed nipple or bleed hole in the calliper may be blocked. Bye, Peter B.

What is the ignition system you have on there at present and what is causing the problem? Try The Hell Team in Sydney for a Kokusan system. Bye, Peter B.

Hi there, best to move the gear lever up away out of harms way. It is reasonably hard to find parts for the Fantic bikes, they have been out of production for many years. Some parts are available from guys in the UK, try google. (Bob Wright and In Motion are a couple worth trying) The bike is a 1991 K-Roo, I have one in the workshop. The fan has a 12vDC motor, you can try this directly across a car battery to see if the fan has failed or if it is something else. If the fan is ok, then next place to check is the thermoswitch, which will make and break a contact to activate the fan. Check this with a cup of boiling water and a cup of ambient temp water and an ohm meter. Bye, Peter B.

Hi Bri, you can measure the finger height with the depth gauge on a vernier caliper, top of the fingers at the centre, down to the base of the clutch centre. Yes, it is the plate thickness that determines the finger height. Yes, the thinner belleville washer/spring would be easier to pull in. The clutch fibres swell when water enters the gearbox, either by drowning the bike in a stream or when the water pump shaft/seal wear and allows coolant into the gearbox, best to sort out those problems promptly when they happen. Bye, Peter B.

Baldilocks, you're still a young lad, I agree with breagh and have always geared down my bikes, GG, Ossa, JGAS and Vertigo always run 44 rear and 10 front, I like to go slow up the becks. Regards the softening/tuning, I watched Jeroni Fajardo practising on his Vertigo in December, where he was swapping different flywheel weights, he seemed to be going ok. Just trying out a low comp head in my 300 Vertigo but not yet over sections so I can't comment. A good friend is using the same low comp head in his 300 and prefers this set up to standard, more manageable at low revs. Bye, Peter B.

Hi xull, looking more like a simple connector problem, that was a lot of corrosion on the ECU pins, definately squirt Wurth type OL in there, both plug and socket. As the bike was fine when put into storage, it is very unlikely that there is a head crack or O ring passing. The ECU takes the temperatrure reading as an input and will output a signal, probably a 12v signal, to the fan relay to operate the fan. This relay is located at the right side of the voltage regulator just below the "tank" cover. It has been know for these relays to work loose and therefore not operate, they are a plug in unit. Pull it out and inspect the relay terminals, they may also be corroded. It wouldn't hurt to disconnect all of the wiring connectors, spray them with type OL and assemble with dielectric grease. Good luck with this. Bye, Peter B.

Hi bondy, not many replies here! Only repack if the exhaust note has become noisy. I've used both the pad type and loose (fibreglass type insulation), both were ok. Bye, Peter B.

Hi xull, Yes, the thermistor is at the rear of the top of the head. 2 wires exit this which run into a dual connector to the left of the voltage regulator, you can measure the resistance here, I just checked one, it is 2.96 K ohms (2,900 ohms) at ambient, which is a freezing cold 17C right now (winter in Auckland). If this is ok, then most likely to be the connectors to the ECU, or a broken wire. If coolant is blowing out straight away from a cold start, either the head O rings are leaking or the head has cracked. Bye, Peter B.

Hi xull, the Ossa uses a thermistor to sense coolant temperature, which is threaded into the head. These alter resistance according to temperature. They are not known to fail, but it is always possible. One of the problems with these bikes has been the wiring connectors, especially to the ECU. If there is corrosion there, don't scrape it off as the ECU pins are gold plated, best to use a contact cleaner spray such as Wurth type OL, works very well. After everything has been cleaned, apply a contact or dielectric grease to the connectors. I don't remember what the resistance value is at ambient temp but measure your temp sensor with an ohm meter and check for this same value along the cables/connectors back to the ECU. Does the coolant over pressure and exit the radiator straight away from cold or after a few minutes of running. Bye, Peter B.

Hi fourex, you can use a pair of Alpina yokes that has the bar mounts directly over the headstock, but, they do not have the 2 degree stanchon offset like the Sherpa ones, which works well for me, sharper steering, and they set the stanchons further apart so you need to machine up a longer spacer for the front wheel axle. Bye, Peter B.

Hi Patrick, the standard carb would be a DellOrto PHBL 26. You should be able to pick up a throttle assy and exhaust pipe and silencer from a long time GG dealer in the states. Bye, Peter B.

Hi fourex, I ran my laptop through a restart which then disabled my TC account and have only now got back in through the signing in after a TC password reset. Yes, I am very sure the needle is a GJH, used on various GG 321 and Pro 300 from 1999 till 2010, with a 128 main and 35 pilot. Needle clip second off the bottom. I agree, the Keihin table indicates the G to be leaner than the J from 1/4 to 3/4 but, the taper of the G is 2 deg 26 mins vs 3 deg for the J, you can see the difference when you hold the two together, which allows more fuel to pass with the G, the fuelling feels richer. The std J would always knock under load, the GJH cured this and provided a more controllable response at low revs. Hope this helps, bye, Peter B.

Yes, a GJH with a standard slide works well, a bit more controllable at lower rpm's and it prevents the pinging/knocking with the std set up. Bye, Peter B.

For the 300 only, I have always used a GJH needle, slightly richer from pilot to mid range than the JJH. If you can't get one in Oz, Allens in the UK have them. Bye, Peter B.

There may be two different lengths of short spoke (and the long one also) that are used depending on which side of the hub you are replacing spokes. Have a look on the parts list to see if there is a difference between the left and right side short spokes. Bye, Peter B.

Hi nzpeterb, it's peterb here from NZ! I had a new original Bultaco bake lever just like the one you are after for years, then used it for a BSA B40 that is now parked up in the Hamilton Motorcycle centre, in Hamilton. If you were stuck, you could contact someone there to ask about that. Can't help with a prop stand. Bye, Peter B.

Hi Bert, if the disc bolt has not been loctited into the hub, you may be able to unscrew it with a scriber. If it is unable to be moved, then you need to drill it out very carefully and run an M6 x1.0 tap through the hole to recover the thread. To drill the bolt out, remove the disc, precisely centrepunch the bolt in the middle, drill into the bolt squarely with a very sharp 5.0mm diameter drill, the correct size for tapping an M6 thread. Sometimes, all of the bolt is removed without damaging the thread, in this case you don't need an M6 tap. If some of the bolt is left in after drilling, then run the tap through carefully to remove any left over bolt. Some guys like to use "Easiouts" which grip the broken bolt (after being drilled to a particular size) and have a left hand thread that bites into the bolt and can unscrew the broken bolt. Sometimes, the hardened Easiout can shear off and this is even harder to remove. Good luck, Peter B.

Hi Vinnie, 75W is a winter 75 grade of oil, which has a low viscosity, it is not a high viscosity oil like EP90 for example. The 75W is fine for your bike, another fine oil to use is a much less expensive ATF oil rated to Dexron III, which I have used for well over 25 years on all sorts of trial bikes. Bye, Peter B.

Try to get hold of alspan, this is Al the Spanner, totally brilliant with trial bike repairs and a thoroughly good bloke, lives close to Durham. Bye, Peter B.

Cut off 4 to 5 coils from the original, always worked in the past. Bye, Peter B.

Problem is very likely to be the selector stop bolt that will have sheared, you can't see it on the drawing above but you need to remove the clutch basket to get to this and will need an M20 x 2.0 pitch bolt to use as an extractor for the centre after first removing the centre allen screw and cupped washer. When refitting the centre, do not use the screw to do this, locate the centre on the splines and tap in with a wooden drift. Bye, Peter B.