woody

How anyone can say any modern trials bike is heavy beats me. I'd assume that they mean it has a heavy feel to the front which is just down to the front/rear weight bias, not overall weight. The 4RT is heavier on the front than some other bikes, so was my 02 Rev 3, but heavy in overall weight - I don't think so

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Yes, I wouldn't disagree with you on that - forgot to mention draining the floatbowl as well as the airbox etc. Was thinking more about the more serious drowning though such as when the bike has played at submarines and taken a lungfull the size of Jordan's

Yes, just like the Mont and Gasgas with the intake right behind them. Not the best of designs eh.... Seems the manufacturers all have a competition to see who can come up with the best design for force feeding crap into the airbox these days.... Use some wire mesh/guaze like they use in car body repair fibreglass kits and cover the holes with it from the underside. You can silicon or duct tape it on or whatever. It'll keep some of the crud out but not all and not water, but better than leaving them open. I actually duct taped over the holes completely on my new 98 Mont for the SSDT that year to keep it out and it didn't affect the way it ran. Still knocked, banged and pinked its way round the road. Bit of a culture shock after minging a TYZ around flat out everywhere the year before. No crap in that airbox either

You may struggle with the cover due to the magnesium content or type of mag alloy used but I'm no expert. A mate of mine is however. He's a top notch welder (coded) and fabricator and has done some incredible repairs for me over the years, but when he tried to repair the clutch cover on my Majesty it just wouldn't weld. He's done some 175 cases but couldn't do the 250. In view of his ability I've assumed if he can't do it, it can't be done. The Mag cover may well be made of the same stuff, hence my opening comment. I'm assuming that your Majesty is an early one with the standard TY mag cover as you've mentioned the magnesium. On later Majesties shirty had an aluminium cast replacement with Majesty cast into it, the final ones had 250/320 Majesty cast into them. These shirty covers have no magnesium so should repair easily. If you'd like a newly cast later type cover as a replacement for yours, PM me and I'll give you the contact details of where you can get one as some have been recast from an original. See photo. No commercial interest for me and nothing to do with me other than mine was used as a pattern. It won't let me post the bloody photo so if you want to see one I can email it to you

It's not really going to make any difference though whether you have a carb or EFI if the bike goes under water. If the engine isn't running when it drowns and water hasn't damaged it, just do as you did and a bike will restart, carb or EFI. If the bike goes under with the engine still running and water gets sucked in, most likely it's going to damage it. One of our local lads had that unfortunate experience on his 4RT. Fell off it in about a foot of water but the tickover kept the engine running when it went under and inevitably it stopped. They got it out, drained everything off, got all the water out but the damage was already done. Bent valves, bent conrod, scored bore etc. About

Difficult to say how it compares with a standard Pinky to be honest. The mono engine should theoretically be better all round than the old TY motor due to it's more modern design. Certainly holds true when compared to a 250 TY/Majesty but when the old 'un is converted to 320 it transforms it. People say they're too powerful but it depends how it's set up. It's possible to get it to run pretty much how you want. When I bought mine it was a snappy power delivery, very sharp and a wheelspinning nightmare. I've softened it right off and I run with no tickover so I can shut it off to an absolute crawl without the clutch. With the flywheel weight fitted it's amazing how slow it will go without stalling (1st 2nd or 3rd). Timing is retarded, bigger exhaust and airbox, all help to soften the delivery. It's quite docile but very torquey and the power is there when you want it. Grips well and no problems with it on rocks. In fact, you can pick your way up a rocky stream quite nicely on the throttle without having to use the clutch - one less thing to concntrate on - throttle/clutch coordination - which is nice..... If there are any trials down your way over December period that I can get too you should have a try on it. You probably won't like the bike's set up but it will give you an idea of how soft a 320 can be

Why does it have to have EFI? Modern motox and enduro bikes have been running trouble free on carbs for a long time now and on the bikes I've owned (Yam, KTM) I've never had problems of any kind. They haven't suddenly gone off tune and run fine whatever the weather. Why shouldn't the trials bike? The EFI is very impressive on the 4RT but it will still cough stall if ridden too slowly under load in a higher gear, just like any other 4 stroke. The biggest problem with that EFI set up for me though is the fact that the tickover is set at 1800rpm and can't be lowered much below that. I generally run my trials bikes with no tickover so that when I shut off the bike does too. The high tickover required by the 4RT EFI means that I can't drop it to snail pace when needed without dipping the clutch, it has to be ridden faster than I like in certain conditions. The Scorpa 4T I tried could be shut off almost to a standstill without using the clutch and ridden old fashioned style on the throttle alone. Same for the aircooled SY fourstrokes. Can't do that on the 4RT. No amount of messing with the PTB mapping can lower the tickover. If it had a normal tickover speed I couldn't fault it.

That's a great bit of nostalgia GIZZA5, really enjoyed reading that. I just love a bit of nostalgia. Now if we could only have a Scottish twinshock 2 day event as well... Just like to echo Hilary's thoughts too, that the whole pre65/SSDT week is a fantastic organisation and a credit to those hardworking and dedicated souls involved in it. Just to feel the atmosphere building as both events get underway is like nothing any other events seem to give.

It's still very fine bead blasting but in a jet/spray of high pressure water/steam so as well as stipping the crud off it mildly polishes as well, leaving a shiny finish as opposed to the dull finish of normal blasting. If you google it you'll get a better explaination than that though...... Works well on engine cases/cylinders on stuff like 70s Jap road bikes such as Z900 to restore the casings to original type finish - shiny but not mirror polished

Not sure personally whether it will make any difference to heat dispersion whether you paint it or not. I only say this because there are many bikes at trials with unpainted barrell/head that don't suffer from overheating - ie; all the Greeves/James etc using Villiers square barrells. Cosmetically, vapour blasting leaves a nicer finish than bead/sand as it polishes as well as blasts so you get a shiny (ish) finish. I had a Bultaco barrell/head done locally a couple of years ago and it was an impressive finish. Costs a bit more than just blasting. To keep it looking that way though is always going to be difficult as the mud will bake on during the event and probably stain the alloy, as it does paint - easier to clean off from the paint than bare alloy? So if you're going to paint it you may as well just have it blasted as the cheaper option, unless there is no price difference between the two where you are. Thing with sand/bead blasting is you can normally find someone who will do it in their 'lunchtime' for a few quid. Vapour blasters are thin on the ground. I think for porting on the 250, Birkett is the only option with the spec and previous experience to do it. Shirty is the only other option but they've no interest in Yams now I would guess. Funnily enough I was chatting to Mick Thurman last week at the Classic Experts and he said his mate has a 250 done by Birkett and it is a nice bike. Still think the best option is the softly tuned 320 though.

Come on then Stu - pictures......

Thanks Steve, but what I'm after is the complete decal for the mudguard which is one length of blue vinyl with all of the sponsors logos printed onto it - just refer to it as the Hamilton decal as they were the main team sponsor

Yes, there is a classifieds section. If you let me know what you want for your Ossas, or start another topic or whatever I'll see if I can help with where to source the parts as they're not so well catered for as Bults

Forgot to mention also that if you go for a Mikuni the diameter of the intake on the back of the carb may be a different size from the Amal, therefore you may have to improvise for the intake rubber/hose from airbox to carb. As regards performance advantage with the Mikuni, personally I don't know. Some say throttle response is better/cleaner with a Mikuni, although the Beta owners seem to hate them. All I can say is that when I had my original Ossa MAR back in the 70s it ran perfectly on it's original MK1 Amal - wish I still had that bike..... When I had a reed valve fitted to my current MAR, I was still using an Amal MK1 and had no performance issues at all. Can't say I've ever found they go out of tune as there is only a pilot screw to adjust. Had a new Mikuni on it in later years and couldn't really tell any difference - other than the constant flooding when the bike was parked up or leant over. Then again, I have another MK1 Ossa which has an older Mikuni from a Suzuki fitted and that runs clean as a whistle right through the rev range - but Mick Andrews set that up. If you do go for a new Mikuni Allens is the best source for that as someone there runs a Bult with a Mikuni on so should have the jet sizes needed. Also, make sure they supply the carb with the rubber tipped float needle and housing to match as it should stop the flooding - did on mine anyway. Why they don't come as standard I don't know...

I'm assuming it just needs a rebore to next oversize and you're not talking about a 220 or 230cc conversion. Contact Gordon Farley motorcycles, number in TMX, and speak to Tim (I think) He knows which piston you can use to fit the Seeley as the Seeley had a bigger piston than the standard RS200 to make it 198cc and no-one seems to know what they came from. He got me a replacement for mine (actually had it in stock) which came from a ditch pump motor or something like. No jet changes should be necessary for a rebore and oversize piston. I actually tried David Silver first but they didn't really know anything about Seeleys so I'd go to Farleys

There has been one on ebay UK too in the last week or so but the seller didn't know it was a 125 and was advertising it as a 250

All of the usual dealers that cater for twinshocks will be able to supply you with a MK1 Amal for the Bultaco or a MK2 Amal for the Mont - I'm guessing that's what the Mont should have. Just that not all of them are likely to have one on the shelf. If you have spec sheets in manuals then there is no problem with jetting for the standard type carbs as the spec sheet will list them. The problem comes when fitting a Mikuni, Dellorto or other as there is no spec sheet so it is trial and error or using someone else's settings as a start point. The places most likely to have the MK1 and MK2 Amals in stock are Millers, Bultaco UK, Surrey Cycles or Hitchcocks. Miller and Bultaco UK (for the Bult only) should know the jetting, the other two probably won't so that is where your spec sheet comes in handy.

Yes you can use the fibreglass tank on the road. The law only applied to new bikes being sold at the time, not those with them already fitted. No lights or indicators required for MOT, they just mark it day use only but some testers seem to want a rear reflector - why? if your using it in daytime only what use is a reflector.... Speedo not needed for MOT but will be for use on the road. Continuous sounding horn required for bikes made after a certain date which I can't remember. You can buy a pushbike horn and speedo from Halfords.

Yes - drop them my way...... brilliant bikes those 200 Yams

Modern bike in Classic - Yes they should get a 5 as it is no stop but there is always going to be a bit of leeway in the marking to take into account a momentary hesitation as opposed to a deliberate stop to regain balance/composure/line or whatever. Momentary stops are always going to happen on a modern bike as they have to be ridden on the clutch/brakes to go slowly. There's a difference between this and a deliberate stop. If a rider sumps out whilst going over a log they've failed so it is a 5. Being stationary and rocking the bike to free it and carry on whilst feet-up is a 5 because the idea is to go over the log in one attempt. That's where the old anything goes rules were a joke - a rider could fail in their attempt to get over the log, hop the bike backwards off it and have another go, and another, and another until they got it right or fell off - usually the latter. Used to be like watching paint dry and seriously frustrating when you were waiting in a queue for your go whilst rider after rider performed this circus act and the queue got longer. However, depends what you mean by starting twinshock trials. Just because you're on a twinshock doesn't mean you ride no-stop. Depends on the event - see my earlier post.

The problem with rule interpretation seems to stem from the type of bike being used instead of the actual event itself. Just because you're riding in an event on a twinshock or pre65 doesn't mean you are riding to the 'old-fashioned', 'traditional', 'old farts' or whatever description you care to use, rules of no stop - ie; a 5 for ceasing forward motion either feet up or down. If you're riding one of said bikes in a modern trial, then the rules will be whatever that club employs, most likely to be stop allowed, hopping allowed (or whatever they are - I don't care) It's a modern trial so you can hop and dance your pre65 or twinshock around to your heart's content, even if there is a pre65 or twinshock class. Most unlikely you will get 2 sets of rules in operation at one trial. One seems to be causing enough confusion... (not meant as a jibe at anyone) If it is a club classic event for pre65 and/or twinshock it is up to the club what rules they run. Most likely going to be tradtional no-stop. If it is the National ACU Classic or the Sammy Miller series then the rules are most definitely the traditional no stop. Stopping and hopping definitely not in the spirit at all.

No, definitely no rule changes required - it's crystal clear. The rider's know it and it's up to them to play by the rules. All you can hope is that the observers on sections where it happens are brave enough to award the 5. I wouldn't blame them for not doing so as not all want confrontation and their decision is made even harder when a crowd of onlookers applaud a clean which has been achieved with a technique that is good to watch (to some) but nontheless illegal. Hard to give a 5 under those circumstances. It was interesting to note in yesterday's classic experts that the best ride on the section where hopping was going on, was by Dave Thorpe who just floated the front wheel 90 degrees or more around the 'bowl' of the turn and cleaned it. Brilliant, proper no-stop and much more impressive machine control than stop and hop. Line perfect and only one attempt to get it right. I still think it may be of some benefit to put notices at the signing on point and on the regs next year in the Classic and Miller rounds emphasising that it is a no stop trial and stopping and hopping will be penalised with a 5. That and reminding the observers when they sign on is about all you can do and just hope that seeing it emphasised will make riders think twice before doing it. Abusing this rule, along with the other favourite of riding out and back into a section between two blue or two red markers (ie - outside the boundary of a section) to get a better line are the two things that really wind me up.

You can run them at 2 or 3 psi without problems - they'll generally stay on the rim even when punctured. Unless there is something wrong with your particular tyre you must have just been unlucky as there is nothing else I can think of that would cause it to come off the rim, unless maybe it was never seated properly in the first place

They were quite popular in the era, our local trials shop used to run TY175's with boost bottles and reckoned they made a difference. I've never tried one so wouldn't know but if you search the forum - Yamaha or Twinshock, not sure which - there was a topic on this some time ago so you may get some answers from that. Alternatively, what about 200cc conversion. Depends how serious you are about the bike's performance and therefore how much you want to spend I guess but I would have thought that would be a better option than the boost bottle. Steve Davies runs a 200 Yam in the Classic series and it goes very well.