section swept

Check the replacement Bart gear very carefully, no tiny indentations, scratches or burrs on the teeth...all can lead to hairline cracks developing eventually ending up as you found. I think the recess machined into the gear body is the problem, it may be there to allow clearance for some other mechanism but its made the gear very thin in my opinion...no pun intended?

Your issue is getting the oil out of the cracked fork. A good TIG welder will want to try a few passes so I would find an old fork leg for them to try their hand at. The aluminium...or USA speak aluminum...has degraded and become brittle possibly due to the clamp being too tight. A safer alternative would be to find another set of good forks, but check the clamp area thoroughly. If its any consolation Paoli made the forks on my Yamaha 660 SM and they were prone to cracking, later models had a different design fitted. Litigation and lawyers especially in the US will have a field day if you intend to let anyone enjoy the bike, as in this potential case you knew the forks to have been faulty and repaired.?‍???‍♂️??‍♂️ Paoli are still manufacturing so an enquiry to the factory might get you the information needed, but I hasten to add if only you are using the bike a weld repair failure is your fault and you won’t be suing yourself now...but if its ‘anyone’ ?

Wouldn’t want to ride on the roads in these days with 6 volt lighting and questionable brightness of headlamp and rear bulb. You get more light from a mini mag light torch, used one attached to the handlebars to ride in the dark....long story don’t ask! Modern bicycle lamps will show more effective light both front and rear and with batteries in top condition will last a few good hours. At mot time ( not a daytime specification mot) standard engine supplied powered lights and horn...depending upon year of bike manufacturer a bulb horn is not always acceptable nor is a battery powered horn, even though it may be more effective...the laws an Ass sometimes. When you haive the mot then fit the bicycle lights, they are both light and small and resist vibration, something a stop and tail light bulb has difficulty in doing. Some riders use a spot lamp fixed in the dipped position with just an on/off switch that meets const. and use regs. A resistor in line for the rear and another for the headlight should prevent high revs blowing bulbs...can’t remember the electrical triangle equation to give the resistance value. R (I) over W x V when I can be a***d I’ll look it up in my notes...some one reading this is bound to dive in with the formula. If the ignition coil (low tension) has been replaced with a modded design the horn wire may well be attached to this and should be fine as no one will hear the horn and you won’t be using it...the engine exhaust note will be enough if its walkers in the way...in traffic forget it, shoutings more effective. I would use the yellow for the horn. Green for the head and tail with resistors fitted. Pink for the stop light via switch to bulb for which you would use a stop and tail bulb rated at 6v 21/5w...a twin filament bulb.??

Who doesn’t want a Steve McQueene Metisse desert sled or even Henry Coles copy!

You are a seriously lucky chap to have such a thoughtful wife, great pictures but a word to the wise that I hope you will take as well intended. Showing, parking your bikes on the driveway in a perfect world utopia. Unfortunately our world is blighted by scrots and toe rags that will see your cherished rides and nick them when you are in or out. My mates had his garage broken into twice by removing the roof tiles and getting in passed the security alarm fitted to the door, they nicked s nearly new quad bike....guess what they were after the second time...yep the insurance replacement quad....now stored elsewhere. I hope you are not targeted, if any of the light fingered brigade are viewing this web site they now know what van to follow to your address, or to break into. Sorry but someone had to say it. You must rate as the best Dad in the world judging by the look of your lad on his bike??

Most probably the reason for so few ‘Rickmans’ appearing on Trials Central is that not many if indeed any were really trials orientated, more trail and fire road use, chasing a market that didn’t take off. Whatever Rickman built frame wise would have been sound engineering but the steering head angles would be less steep than a real trials iron.

Part exchange?

Sale price, try offering it at the price you paid originally, you can always lower the price if a prospective buyer seems really keen. Just hope not too many of them have seen your post on the repair. Now that you have resolved the issue why not just enjoy the bike and ride it. I doubt the porous casings were due to any bankruptcy more down to poor casting which would be done in batches. Why did your engine man not get the cases welded, I would imagine the cases are now weakened as epoxy won’t be adding strength.

If turning a tight circle ie figure of 8 then leave the front brake alone, look where you want to be not directly in front of the front wheel (in this case) otherwise you target fixate. Try just riding as tight a circle as you can comfortably manage in clockwise and counter wise, looking where you want go and not down at the area immediately in front of the bike. If you cannot operate the back brake can the pedal be altered at all to allow you to pivot your foot but still dab the brake. The rear brake accentuates the bikes turning ability provided the throttle is constant and the rear brake slows not stop the rear wheel. An alternative is to use a handlebar lever operated rear brake... this is stunt bike rider and racer stuff that may cause a few to chuckle on here, but it is also used by some handicapped riders. However, if it allows you the option of both foot and hand lever rear braking it might just help you to achieve what you are aiming for.?

Yes you are correct and I think you will find this is peculiar to certain engine design such as generator engines and some commercials. Although keyhole and pear shape I have seen in cold start devices for fuel injected engines. Some throttle plates had a small valve in them to allow air to bleed into the inlet on overrun to reduce emissions supposedly. Others used tiny T shaped cut outs for idle stabilisation, later to be replaced by an electric solenoid valve or AIS air idle stabilisation valve as it was labelled. Do you remember some big four stroke singles used more than one carb, both were of different choke size to offer more power but the fad never lasted very long...neither did the engines I fear! I want to see some enterprising person try fitting fuel injection to an older 2t trials engine, but I think this will only confirm that the carb has a better ability to control the fuelling from idle to mid throttle over the FI system. Wal Phillips tried with his basic fuel sprayer but his success can be measured by its failure to be reliable or work at all on some engines. Even the first fuel injection of the electronic variety was vert crude by comparison to what it is now, I cut my teeth on mechanical petrol injection and stayed with this development right through to 3D mapping. People would be amazed at just how rough and ready some ECU fuelling maps are even now. All of the shapes used for carb Venturi (choke) that you mention had an effect but invariably to minimise fuel usage and hence emissions at idle and fast idle. Roll on the Euro emission legislation...designers and engineers get more inventive every day!??‍??‍??

Think you will find that a flat slide carb is great for wot performance and more instant off idle zap, but for trials work a conventional slide carb offers best fuel metering in the first quarter of throttle opening. Its taken many years to perfect fuel injection to get to the stage where low speed throttle control is smooth as with a carb and not erratic. Some tuners throw away the fi and fit carbs for more refined fuel control but then they are after out and out power. Fi can now be so accurate in its fuel metering that its being used on nearly everything thats got to be EU emissions compliant. Note flat slide carbs tend to be affected by wear more quickly due to less surface support area for the actual slide, an additional consideration that offers less friction when snapping open the throttle...why some like them too. To reiterate, a small carb will improve low down engine response to some extent but it won’t increase the torque, a longer inlet will also improve the low to mid range performance...have a look at variable length inlets and two or more throttle plates to affect air flow into the engine. The plenum chamber in most engines hides either sliding venturi tubes or static long tubes to give plenty of oomph in the low to mid range but a breathless performance at the top end...variable length stops this as does more than one throttle plate/body. Not so easy to accommodate in the confines of a trials bike or most other bikes, but common on many vehicles since the 90’s. You could experiment with restrictive collar sizes (not shirt size?) this will restrict the volume of air that passes through the carb but not the velocity which will remain constant ( effects of atms pressure). As an aside are you located high up in NZ as air density will be affected by thinning air (reduced oxygen content) and humidity will play its devious part in messing with carburation. Its a pity we can’t get our heads together in person (Covid safely) as it would be great to experiment. A 25mm and 50mm inlet extension can make a noticeable change to low and mid range but the Fantic may prove to be problematic space wise. The Rotax crank induction engines had reasonably long inlet tracts hence their suitability for trials work the carb being some way back from the actual crankcase. Then look at road race 2t race engines with c/case induction and the carbs are virtually straight onto the crank case mouth with hardly any manifold at all! Its perverse in some ways, people chop holes and add extra slots and use ‘special’ filter elements to improve engine breathing or fit in the case of Bultaco larger volume air boxes from the 159 model to give the engine something to go at...a reserve of air if you will. Yamaha introduced their additional air box on the IT range to improve mid range engine response but soon lost it to other developments, I’m surprised its not reappeared on 2t trials specials, it seemed to be beneficial...food for thought. Hope you find achieve the result you are looking for??

Gentlemen, I think that there have been some very good points raised in these posts. The main one being that the consensus of human beings act like sheep and need to be led, they have little by way of common sense demonstrated by their Lemming like behaviour when the sun (thats the sun in the universe and not the tabloid paper) appears, or head to the pubs and restaurants. Lock down was too late, borders were closed too late, NHS support and Care Homes support came too late, our doctors and nurses and front liners support came woefully late....but then now we know what we need to do people still insist on ignoring the developing advice to avoid wreaking Covid-havoc any further. Dominic Cummings actions beggars belief and I am surprised he remains as an advisor...on what I dread to think. I truly am in awe of anyone suffering with Cancer and also of the families and friends dealing with the outcomes and expectations. But its not a virus unlike Covid which coincidentally was on the lists of some disinfectant sprays ‘before’ the break out occurred! By comparison to what clubs running trials are suggesting it should be no more threatening than visiting the supermarket for essential shopping. Browsing in small crowded shops is asking for trouble. An arena trial no way, but outside in the free air...not re breathed other peoples air...far safer, provided common sense rules are followed. Having a go at each other is not productive and in this case has created a negative impression about trials....shake hands and move on with positive ideas for all to consider to keep trials alive and to help our mental welfare and to think of somethings other than negativity.?

Side stands are very useful but they add weight and very often by the time you find a bit of solid ground its time to move. Annoyingly it is sometimes the side stand that causes a few dabs when it catches on something. I prefer to lean the bike on something reasonably solid tree etc, ask a bystander or mate to keep the bike upright (reliable) better sometimes than to return to the bike only to find the stands sunk and the bikes on its side. ?

The usual suspects....levers, chain link, gear lever, twist grip....you never know. Pretty much the same as for any trials machine. It’ll always be the bit you haven’t got in the van that lets you down....how about another complete bike...just like the works boys do. Master cylinder and slave complete or repair kits. The list could be endless, depends on your level of commitment in the sections and how much you don’t mind bending your bike to compete. Apart from oils and fluids maybe a sensor or two and some ready made up bridge by-pass wire links...one taped to the bike ready just in case you are too far away from the van. Seems to me that the more you take the less you use, then there are those competitors that have everything including the kitchen sink but never use a single spare... not even air in the tyres...very annoying. ?

Contact InMotion and state engine number they will supply what you need.

Velocity....or volume of air? By lengthening the inlet manifold you can gain an increase in low to midrange torque, thats not an increase in torque just manipulating where the torque is. High revving engines have short inlets and big throated carbs, mess too much with what the manufacturer intended and you may spoil the performance for trials work. You say ‘the bike is not used for trail riding or road use...more explanation please. If you look at engine power and torque figures you will see that there are some commonalities where by the torque and power figures at certain revs are the same, this is due to our earths atmospherics. For smaller engines like a 125cc or 156cc the same rule applies. The velocity is speed and the Venturi creates the increase in air speed as it passes over the main jet (like an aircrafts wing shape) causing the fuel to be drawn out into the airflow. Bigger carb allows more air but the same ‘velocity’, superchargers and turbos force more air volume into the carb or throttle body for FI systems. Gravity unfortunately is the regulator that engine tuners have tried to overcome but the only way is pressure charging in some form. Smaller carbs ie 22mm would give you better throttle response at low revs but have a restrictive effect at higher revs reducing effectively the power available. Two stroke tuning is not just about the carb size, alter one thing in system and it can affect the rest. The exhaust system affects engine response and its ability to ‘breathe’. Varying the length of the exhaust tail pipe affects the engines abilty to rev hence the way an expansion chamber is designed. Should you try a 22mm carb you will most likely find that the engine is good for trickling around obstacles and gentle climbs but the moment you want that extra ‘zap’ or power to lift the front wheel or climb a significant hill etc you will find the engine lacking in power. Its not by chance that nearly all trials bikes with carbs have very similar carb sizes. What I will say is that you might find that two carbs of the same size but different make will respond to your engine their own different ways due to design and fuel metering. So from idle to quarter throttle the fuel metering may be far better controlled by one make to another, then the transition stage from off idle to more than quarter throttle opening you may find the engine experiences flat spots or hesitation while the fuel relents from the idle to main jet and throttle slide and needle movement....some carbs are really smooth whilst others a rough and cause unpredictable engine surging. Tie all this in with engines of varying states of wear with seals, rings and bearings and you can probably imagine that the previously mentioned faults will exacerbate the situation. Fantic had a pretty good idea of what was best and I don’t think that altering the original carb size will improve the little Frantic Fantic, these bikes do a brilliant job when pitted against the rest. Spot on fuelling and engine set up is what will make your bike useful for the type of trialing that you do ?

88th on me NSU Quickly....with leg shields removed and pedals drilled for lightness!

Blimey Rossi in second place...thats rare now. He had been languishing in the mid pack last season but now he seems to have got a new mojo. High track temperatures meant most riders had tyre trouble with degradation and slip which caused at least 5-6 biggies and at least one stretcher case. In the end Rossi failed to make it a win, but it is good to see him out with the front runners.

Anyway, hello and welcome to you littel. Whats wrong with the TY250 Monoshock fork caps. If they are a bit chewed due to socket/spanner slippage etc they can be gently filed back to shape....how is your metal working skills. Here in the UK there are a few good suppliers of TY spares and accessories, good old Google can be a help. Hope you get sorted??

Well spotted Chillipig. Might be a good idea to use your eagle eyes to thoroughly check the rest of the bike over for ‘other’ faults/issues.

As you have owned this bike a long time you will appreciate that it like Bultaco and Ossa are fairly basic in their design and operation. From experience the Clymer manuals tend to have much more info than Haynes, both are useful for tech specs and photos of assemblies etc. But there is so much experience and information available on this and other web sites. Adjustments are fairly simple externally but shimming and gear change settings a bit more challenging. If you photo everything you are wanting to take apart or repair/replace before, during and after work this will stand you in good stead. As your bike is getting on things like seals will need looking at and probably need changing, as will bearings. Even with a manual by your side there will be work procedures that sometimes fox even the most practiced of us. Your Montesa must have seen you carrying out maintenance and some repairs before now, so depending on your engineering diy skill levels and with help from Trials Central members you should be well set to do what ever to your Cota 247 ?

The proportion of ethanol in fuel depends on location, some Shell and Esso fuels have no ethanol content...yet?‍♀️! Whilst in other parts of UK there is at least 5% ethanol present. There will be issues when 10% ethanol is used and there is a list of vehicles that will not be able to use this particular fuel, but they may be able to use the super type of fuel eg V-Power etc. All info available on Google look for Octane magazine. Old aluminium tanks may be brittle and may crack when subject to regular use...usually around any mountings and areas of chafing. Aspen 4 professional will be your best bet but its about £20 per 5 litres or £6 a litre...at least it is where I buy it but on e-bay its £33+ and then p&p!!! There are ways to isolate the ethanol shown on youtube...but I am not convinced...yet?‍♂️??

This Monday 18.00 on Channel 12

Well pounding on the lever will probably bend a selector...not the way to go! Photos of your identified fouling problem would be helpful.