woody

Thanks for all the help guys, looks like I do have the correct inlet manifold thingy so hopefully, this weekend, we shall have life...... or tears

Thanks for the help guys. Looks like my manifold/inlet bit is the same as those in your pictures. It could be that someone has remade the airbox which is why it appears not to line up fully but it is only a bit out so should fit with a bit of tweaking. The only thing I can't identify is the object on the far right of your picture TLRS - what is that as not sure I have one - may be in a box somewhere Mark - Central Wheel in Coleshill can make you spokes in various design/pattern if you send them an old one. They have to make the nipples too though as they can't do metric threads I believe.

Thanks for that Mark - the old card and tape method eh... effective isn't it, I've made a couple of airboxes like that. I'm glad you said there is nothing in it as I want to have a go at making one for mine and it is easier if there are no internals. The one fitted to the bike is quite neat but it is steel and I'd like an alloy one. Must get it running first though...

Trying to finish builing the box of bits I got that was once a Seeley. Put the engine in the frame and last week and went to fit the carb and found I had no inlet gasket/stub/mounting - whatever you call it. I got one from an RS200 yesterday as they look to have the same carb positioning as the Seeley and have the same hose from the airbox to carb inlet. Tried to fit it all up on the Seeley and the hose didn't seem to want to line up too well from the airbox to carb. It may be because the airbox doesn't appear to be original and has been made so maybe it is out a bit because of this. I've attached a copy of the inlet stub from the RS200. Before I carry on trying to make it all fit with what is the wrong stub, if any of you have a chance can you have a look at your Seeley and see if it is the same as this one. Thanks

Riding without the clutch has nothng to do with 2-stroke / 4-stroke riding style. There are plenty of 2-strokes that can be ridden without the clutch all of the time, although on any bike you'll need it in real nadgery stuff. I just don't like to be on it all the time. It's all subjective as it depends on how you like to ride, but my 05 280 pro was different from my mate's 04. It was less smooth, quicker off the throttle and had a different exhaust note. Riding on low revs it was difficult to ride without the clutch as the bike wanted to leap ahead and the power was jerky. This is on a whiff of throttle. If your style is point and squirt, dip the clutch/brakes then go again you won't notice it. My mate's 05 250 was the same but with the weight fitted it can be dropped to nothing and will happily plonk up sections clutchless.

PERCE - be worth getting a go on one fitted with the flywheel weight if you can as although it improves the rideabilty a good deal at the bottom end the engine lost none of its pickup, not sluggish by any means, it just smoothed everything out - best of both worlds. I liked it a lot and generally I hate the way most modern bikes ride off the throttle. I know what you mean about the carb to airbox fit. Took me ages to figure out I wasn't doing anything wrong the first time I was refitting it, it's just how they are.... There is no way you can achieve the same result by jetting as you can with the flywheel weight. If I'm wrong I'll eat an old airfilter. I'd hardly call it messing about either, just a simple bolt on job instead of hours messing with the carb by trial and error. I know the weight works as I've ridden the bike before and after - and a good few motocross/enduro bikes too.

I've ridden a friend's 05 250 Pro with the flywheel weight - before and after. I didn't like the bike at all when he first had it, almost impossible to ride without the clutch, engine far to snatchy and lumpy. which made it very difficult to shut off and then just feed the throttle in again, always had to slip the clutch. And yes it stalled easily too, as did the 05 280 Pro I had briefly, just stalled for no reason. This wasn't because it was new either, it was like this long after it was run in. With the flywheel weight fitted there was a noticeable difference. It can now be ridden on the throttle very slowly with no snatch or lumpiness, the flywheel weight has ironed all that out. Engine can now be backed right off and brought in again slowly - you've time to think and are not chasing it anymore. Doesn't stall for no reason anymore either. In my opinion well worth fitting and much better than the head spacer kit. I fitted one of those to the 280 and it was barely noticeable, if at all. In fact, a mate did it for me when he borrowed the bike and if I didn't know better I have said he hadn't done it.... Can't comment on how difficult it was to fit but I've put them on enduro bikes before and they are pretty straight forward. You may have to remove the flywheel to do it though, I think he mentioned, so you'll need a puller.

TLR250 barrel and piston just about impossible to find I'd guess. I'm interested in what can be done as I have a TLR200 which I got cheap but needs some work. I was thinking about using either it or the Majesty in the Classic series next year to replace the ailing Ossa. I think a well set up TLR will just edge a Majesty but I could do with a bit more power/torque than the 200 has. All pipe dreams at the moment as the Majesty has to be finished first, but after that, maybe. I'd love to get one to 270, or 300..... Anyway, good luck with the 210 conversion. For a TLR200 or something else?

TLRS - Thanks for that info. Sounds suspisciously like you may have done something like this at some time. Have you converted a 200 to a bigger bore/stroke?

Nice job, just out of interest what is in it? Empty, a baffle, or core with packing? Any idea what is in the middle box? Griffiths - any news on what's in that exhaust Interested to know as my Seely has a non-standard box on it. Neatly done but steel and I'd like to get one done in Alloy eventually. I can cut it open to see how it is done, that's no problem but just interested to know what you've done inside yours. I'm also interested in hearing what mine sounds like if I can ever get around to getting it running....

No problem, just glad if I can be of any help and hope you solve your problem. Although I own and like my Mont 4RT I like the Sherco too and hope they relosve the little niggles they seem to have. Nothing like a bit of variety out there in the sections. Sounds like a novel solution you may have found to your hot starting problem. You ought to post that on Thumpertalk as mulling that one over would keep them busy for days

Took the hotstart button out and had a look. It is just a simple pull/push plunger that sits in an inlet tube which is 8mm in diameter and about 1 and a half centimetres deep - although this depth is irrelavent really as it depends on the design of the carb. At the end of this tube is another which looks to be 5 - 6mm diameter but I have no idea where that goes - presumably into the carb inlet itself. The plunger I guess uncovers a jet somewhere in the side of the 8mm tube to allow cold air in - couldn't see into it properly but I can't see any other way it works. This jet must be open to the atmosphere somehow, presumably through one of the many pipes that come off the 426 carb. I guess the remote handlebar fitted hotstart wouldn't need the additional internal jetting/plumbing, just the inlet, as the valve which opens the inlet to the atmosphere is on the handledar mechanism and connected to the inlet via the pipe. The kit can be bought from any motocross/enduro retailer but they aren't cheap - about

But there is so little room to fit a bigger liner before you hit the studs. The Seeley/RS200/TLR200 bore is 66mm which, with the 57.8mm stroke gives 198cc, so there is never going to be enough room to get 250cc on bore alone as it would need a 74mm bore which means an OD on the liner of at least 78mm assuming 2mm thick liner. That takes you straight into the studs I think so they would need to be relocated along with the oil feed. Maybe they stroke the crank too. Can't remember what the bore and stroke is on the TLR250 - 70mm bore I think which would make the stroke 65mm. I don't know what you can stroke the crank to on the 200 engine - TL250 also has a 57.8 stroke and they were lengthened to 71mm in the works 305 long stroke bikes, retaining the 74mm bore, but I thnk on the 200 engine the gearbox gets in the way of stroking too far. Maybe they will go to around 65mm though but there aren't any 70mm pistons as far as I know as it is a bit of an oddball size. Interesting stuff - shame I haven't a clue what the answers are, or the engineering skills to 'have a play'.

That would explain why I've never thought of them as a proper trials bike. Didn't realise they did two models. I'd love to see inside one of those 250 converted motors to see exactly how they accomodate the bigger bore, and to see what they do to the head/valves - then if I can just get someone to cast me a cylinder.....

Nice job, just out of interest what is in it? Empty, a baffle, or core with packing? Any idea what is in the middle box?

The Seeley and RS200 share the same engine - the Seeley unit is plated RS200TE. There are/were 220cc and 230cc conversions available in Japan for these engines, don't know who by but may well be Kondo. They use the existing cylinder so the engine looks the same externally. The 220cc is an overbore but the 230cc involves crank re-stroke I think, I'm not 100% certain of this. One thing is for sure though, there is very limited room in the cylinder to bore it out much, even with a new, larger liner, before you meet the stud holes. I've looked at my own engine and as RS says, it must take some extensive work to get them bigger than 230cc as the cylinder stud holes would have to be relocated by the look of it As far as an RS200 goes, from what I've seen of them I'm not sure how competitive they would be. The steering looks very lazy and I've no idea what the chassis is like. Then there is getting one and the cost of it. They are as rare as rocking horse teeth here because they were never imported. Value seems to be above TLR200 from the few I've seen for sale. The ones I've seen also look like a trail bike (picture attached hopefully) although there seem to be several aftermarket tank units available. What about a TLR 200. It would cost less to buy for a good one, the same conversion can be done to the engine, whilst it probably has a better chassis than the RS200 - unless you want something different of course. You could always speak to Ian at Ellastone Offroad (number in TMX) as they occassionally bring in some of these converted 220 and 230cc engines (local bloke has bought one to put in his TLR200 although hasn't fitted it yet) I think they are around

I fitted a remote hot start kit to my YZ426 a few years ago. All this involved was unscrewing the standard one from the carb, replacing that with an adaptor to which was fixed a piece of clear pipe (same size as carb overflow pipe roughly). The pipe went to a device on the handlebar which was just an on/off valve - when open it let air in to help with hot starting. It wasn't any more effective than the standard device in terms of starting efficiency but it just meant I didn't have to grovel with the carb mounted lever when I'd crashed and burned a stinking hot engine so it was a time saver. The inlet into the carb (inlet side of the body) was I'd guess about the same diameter as the internal diameter of the pipe but all this is approximate you understand. I don't know how you would modify your carb to take something like this though. In operation, as soon as the engine fires you knock the hot start off as it only serves to aid starting, the engine won't perform with it open. I have a WR426 now with the standard hot start as I fitted a YZ450 cam which has auto decomp fitted and starting is much easier. If I can get the hot start button out I'll try and measure the intake hole for you but it may be a couple of days before I can do it.

They were probably the best twinshock at the time they were current in terms of an all round package although people will always have their own opinions as to what is best as it can come down to personal preference. I certainly have no allegiance or affinity to Fantics as I had a nearly new 240 at the time and hated it. Couldn't get it to grip always and the power delivery was too snappy. I didn't give it much of a chance though and improving the way it was set up may have helped but I never felt comfortable and just wanted rid of it. It was used however and may have been messed with and it was also one of the first, later bikes were softened off but I never tried one. There were bikes around that were more powerful and the Hondas had better suspension but the 240 just seemd to do everything well - even grip, maybe it was just mine. Clutch and brakes work well and the suspension and steering geometry is good. Basically, if it is a good one you just ride it and don't have to mess with anything. If you're tall though you can be a bit hunched over the bars and dropping the footrests would help that. If you're not it's not a problem. I think the spares situation is reasonable so they are a viable proposition for regular use in twinshocks. Best thing to do is try one, but make sure it is a good one or you will not get a true impression of how they perform.

I always wondered why the green. His current bike just has a green top yoke. Alex was at our centre trial at Hawkstone recently so I was able to ask. Green was the racing colour of Alex' dad's brother Simon, world long track champion.

Had one years ago. Great engine. loads of torque and they find grip really well. Just the steering that isn't to everyone's taste as they have a fair bit of trail, similar to some Bultacos. OK until sections start getting a bit tight, then they can feel a bit long but not many sections like that in the twinshocks really. Some get on with it some don't, it can be altered if you know how/someone to do it, depends how serious you are. I'd say they are only a fraction behind the best twinshocks which are Fantics and sorted Hondas/Majesties and on a par with the other later bikes. Get it out and have a go.

Guessed what he was doing as soon as you mentioned the mono engine as I was going to do it myself. I'm not against modifications if they are 'period' but it is hard to define that. If it was something that could be done at the time, then it is ok. There was a lot more modification going on with bikes back then than people probably remember. Lots of experimentation with swingarm length and positioning, damper positioning, steering angles, exhausts, reed valves etc. but I guess the Yam Mono killed it all at a stroke. The bikes ridden by the works riders were always different from customer bikes in one way or another. I was going to put a mono engine in a mini majesty or 175 frame to make a sort of replica of the last 'works' Majesty. These were smaller frames than the usual Majesty and had a special 6 speed motor, nothing like the twinshock TY250 motor, but very similar to the Mono. There were only about 3 or 4 of these bikes made I think. They were almost a mono without the mono, if you understand what I mean - pretty good. They were never offered for sale, works bikes only. So putting the mono in the smaller frame I thought was viable as it was sort of replicating one of those works bikes. Anyway, didn't have the skills to do it so forgot about it - and I probably would have felt like it was cheating.

I don't think it will. The TY175 and TY250 twinshock have different backplates according to my mate who borrowed a 250 stator from me. I don't know this for sure myself as I don't have a 175 but he said the 250 plate wouldn't fit. Think the 250 may be larger diameter. The flywheels are definitely different. So as the 250 twinshock and the 250 mono backplates are the same, I don't know what you would have to do to get the mono to fit the 175, if there is anything. On the 250 twinshock the mono stator fitted staight on and worked with the twinshock flywheel. It was just trial and error to find a firing point as the timing marks obviously don't align. Once it's fired up it can be timed with a strobe, or just trial and error until it runs ok. I haven't used the bike with this set up yet though but I knowof someone else who has/does and it works fine. There is an electronic system (of sorts - I'm not too technically minded when it comes to electrics) available by Australian company called Atom ignition that is supposed to do away with points and work with any 2 stroke engine. Don't know where you get it from or how well they work but they are a heck of a lot cheaper than anything else available. Someone on another forum was trying one on a Sherpa but never gave any feedback as to how good/bad it was. I know you can buy them for Bantams for about

I think the trail and twinshocks competed in the same class last year in the Sammy Miller series. Twinshocks were supposed to have their own class but it didn't happen untill this year. And they were also supposed to be Pre-76 and Spanish.... I can guess what is going on with a Mono engine. I was looking at putting one in a mini majesty or TY175 frame a while back along with other mods but in the end thought sod it as it was a lot of work, most of which I coulcn't do and ultimately, I felt it was cheating a bit so scrapped the idea. Then I thought, well, it's nothing that couldn't be done when twinshocks were still being ridden as the Yam Mono was a couple of years ahead of other monos, so I thought it could be classed as a 'period' mod. Then I thought sod it again, sold the engine and kept the ignition for the Majesty. So, at a guess I'd say that a tweaked mono engine is going in a mini majesty frame with discs etc. Near the mark or way of..?

When you consider what

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