peterb

Have a look for a break in one of the signal wires going to the injector from the ECU, check each wire for continuity from the female connector block at the ECU, back to the injector. Check for any corrosion on the ECU terminal pins, if there is any, do not scrape this off with a screwdriver as the terminals have a thin gold plate, use a good contact cleaner like Wurth type OL, this works well. Konrad mentioned a "limp mode" there is this type of function in the Ossa ECU should the coolant temp sensor fail, then the fueling runs rich so the motor will not tend to lock up. I think the fan is continuously energised also. Bye, Peter B.

I can't quite understand all of it but essentially that bike at the end, the 315 based one is very special, built by Antonio Cobas as a prototype and was the only one built. There is no mention of it forming the basis of a 2T resurgence from Honda. Pretty sure that the 50 years of Montesa history is staged at the Basella museum, which is a superb motorcycle museum not too far inland from Barcelona, about 2 hours drive and is full of Spanish trials bikes plus a replica of an early Bultaco workshop, it is a great place to visit for any trials rider - and close to an affordable Parador if you ever fancied staying in a 1,000 year old castle. Bye, Peter B.

Just for a bit of history on Bultaco a couple of years back while in Girona, I had lunch with Narcis Casas who co-founded the Gas Gas business, and who used to sell a huge amount of Bultaco's from his shop. He told me both he and Josep Pibernet used to ride in the Spanish Enduro national champs, on Sherpa trial bikes in the early days. Narcis came up with the idea of converting a Sherpa into a more potent type of enduro bike and so he put together the first Frontera prototype and raced this to many sucesses. Pretty sure that between Narcis and Piber, they won several Spanish national champs and sold a stack of Bultaco's too. The first prototype that Narcis put together was given to the brilliant bike museum in Basella who were restoring it to as new condition. Bye, Peter B. After thinking about it, the model Narcis came up with was the Frontera, not the Alpina as I had originally thought, sorry, memory lapse! He used a Pursang frame with a trials motor, altered the steering head angle and a few other things. The original bike was presented to the owner of the moto museum Basella to commemorate his 80th birthday.

I used to own a 305 for a few years, looks the same as your photo except it had proper forks. It was a light bike for it's time with usable power and fine handling. The smaller engine tended to be a little peaky, The motors soon developed piston slap and getting pistons these days is not so easy. The engine/gearbox was well engineered and gave little if no trouble at all. Some parts are available from the UK, not the easiest of brands to get spares for. Getting the front mudguard supports are really difficult, a French company did make a batch some years back, I am sure they would have all been snapped up as they fit other trials bikes with similar USD forks. Have a good search for plastics, rear guards were another difficult item. Overall, a well thought out bike with awful USD forks, the larger motor was the better of the two. Bye, Peter B.

Hallo Dr A, even with C3 clearance there should be no up/down play along the crankshaft, I would suspect the bearing manufacturer. Taking in water through the carb and letting it sit in the crankcase would also cause such a problem. Bye, Peter B.

Sorry Bultaco82, I meant to ask what year bike is the original posting, Pete ML. Bye, Peter B.

What year is your TXT 125?

Hi Herman, did you fit the spacers in line and then pushed the gudgeon (piston) pin in? The 2 spacer recess's should butt up against the needle roller cage and then the pin should fit through - did you try this without fitting into the little end? If this method is unable to fit then you should contact the supplier. Bye, Peter B.

Yes, you are correct re your final paragraph, unsure about the correct way round for the bushes, try it both ways. Bye, Peter B.

Pretty sure the s/arm axle was an alloy steel, but you could likely use a 6000 series aluminium alloy, check the tensile strength first. There would have been a bush inside the needle rollers of the s/arm, either end, that protrudes out of the bearing area of the s/arm which takes up the gap that you mentioned. Doesn't really matter about the ridges on the snail cams. The older brake callipers had a bleed nipple threaded into the top of the hex head of the banjo bolt, if there is not one there you could modify a bolt to suit. Bye, Peter B.

I am pretty sure that it is not possible to change to a batteryless kit on the 2016 model, unless you have the 2017 stator, flywheel and 2017 map. Bye, Peter B.

Move to a drier part of the country, like Yorkshire. Bye, Peter B.

As above, white smoke is usually water. It is possible that the cylinder head O rings have hardened up and are leaking allowing water into the cylinder. Have a check also on the clutch cover sight glass to see if the oil in the gearbox/clutch looks clean, or is a milky colour, indicating that the water pump shaft and seal are leaking. Bye, Peter B.

If you send me a PM to my TC mailbox with your email address, I can forward you an email with 4 PDF files showing wiring diagrams and cable connections. Bye, Peter B.

Looks like a LWB Series III Land Rover holding the bike up. Good bikes those 321's, grunty motor, not much goes wrong. You don't need to buy a new master link, just undo the spring link and re-fit with pliers, closed end of the spring facing direction of chain travel going forwards. Keep the air filter clean, clean out the air filter box, they don't seal very well so water does get in, strip the carb and blow out all the passage ways and re-assemble. Needle is a D36, clip position 2nd from bottom, pilot screw set from 3 1/2 turns out from fully in, as a starting point. Out to richen, in to lean. You don't need a Gas Gas specific chain pad, most blocks will fit from other trial bikes, check the bolt hole distance between centres. Change the gearbox/clutch oil, it says 700mL on the casing but 650mL is fine, I always have used ATF rated to Dexron III as my preferred oil for well over 20 years, it's cheap and it works well, others have their own opinions. Great bike in it's day, not so easy to find wheel grip in the mud, a good Scottish bike. Bye, Peter B.

Hi Paul, the early 2017 models had problems with the fuel pressure lines inside the fuel tank where the lines could rupture (inside the tank) which means you are not getting sufficient fuel pressure to the injector and the motor feels like it is running lean and is fuel starved at higher revs. If these are your symptoms, then it is likely that a hose has ruptured. I found it very difficult to locate any flexible 6mm fuel hose in NZ that was designed to run under pressure and fit for immersion inside a fuel tank. Vertigo have replacement kits for this, try your local dealer. Bye, Peter B.

The area above the threaded part of a bolt is known as a shank. Bye, Peter B.

I am not familiar with the Hydria system, but if it is functionally the same as the Kokusan, then there would be a ground wire from the HT coil to the chassis, check to see if the connection is a good one. Use an ohm meter for continuity, HT coil ground/earth to the motor, it may be just relying on the coil mounting bracket to the frame. Bye, Peter B.

Those gearboxes don't usually give any trouble, Best to rule out the easy things first, is there a lot of drag on the clutch? If yes, then this may be the problem. If the clutch is working properly, then the problem is gearbox related.Have you got the right oil type and quantity in there, 600ml is enough, I use ATF Dex III for the past 25 years or more without problem and with good clutch action, other blokes will tell you different based on their experiences, whatever works. Next to check is the indexing plate spring, It's behind the clutch basket. I have had to replace one of these years ago in an older bike for a similar problem, the spring had lost a bit of tension and did not provide a positive location for the shift drum. Hope this helps, Bye, Peter B.

Certainly looks like a tooth from a gear, best to have a look. Bye, Peter B.

Busto was in front of Bou going into the final section by 1. Dabill and then Raga fived this section, then Busto rode and just as he had got through the hardest part, he lost his balance and fell off the bottle (lost his bottle!) getting a five. Toni Bou rode next and saved his best ride for last as he took a steady dab on his way through. The final result was as posted earlier, with Bou picking up 1 time penalty and Busto collecting 2. Bye, Peter B.

Results are on a Spanish website, probably not PC to post here, Bou 8, Busto 14, Raga 16, Dabill 17, Casales 20, Toby Martin 21, Peace 23, Price 24. Bye, Peter B.

Check the fan is blowing a bit like a hair dryer, with a battery hooked up to it. A standard nitrile O ring would last a short time before the heat of combustion would find a way past. Have you tried Gas Gas UK or one of the GG dealers over your way, maybe the Splatshop. Give them your model, year and cc and ask for the head O ring seals. While the head is off, have a really good look for a possible hairline crack in the O ring grooves. Bye, Peter B.

I'll have a look for a wiring diagram for your 1993 250. It is difficult to diagnose without actually seeing the bike in real life, can you ask a knowledgable trials friend to look it over? The fan itself can be tested with a car/bike 12vDC battery directly across the contacts. Sometimes the fan motors fail and can occasionally turn over albeit rather slowly. If the thermoswitch has been bypassed, then the fan should be on all the time. You say the bike has a new head gasket, there are 2 O rings there, the inner one must be viton, not the usual nitrile O ring as these will not last in this application. What was replaced in the water pump? A shaft and a seal would be required. Although not a known problem for this model bike, there could be a crack in the O ring grooves in the cylinder head which could cause your over pressure problem. Are you sure the water pump is actually rotating? The drive to this pump is by a plastic gear which is very easy to break if not aligned properly when re-assembling the clutch case, if this plastic gear is broken then the pump will not be turning. Bye, Peter B.

Grazie Alberto