oldjohnno

I enjoyed that very much, thank you!

I don't really have a favorite engine and I don't think engine performance in the conventional sense is all that important in the overall scheme of things. To me a bikes ability to turn and the performance of its suspension and brakes is much more important. As far as engine performance goes what is critical I think is its ability to hook up. A low rpm torque response that is too sharp is probably worse than one that is a little soft in that it can badly affect traction and make riding difficult and tiring in the really tight and loose sections. I think almost any engine could be made to work very well with careful tuning and flywheel weighting, so it probably comes down to weight, gear ratios, clutch feel and so on.

The plates you need were used on lots of different Japanese bikes eg. 98 - 01 KX80, Honda VF500C and VF500F, 86 - 94 CBR250RR, CRF150, XL200, 81 - 82 CR125, CB125, 01 - 15 KX85 and many others. You just need to file the lugs a little narrower. I like the CBR250R version best as it has a bigger ID and a narrower contact ring - less drag, more grip with the same or less spring pressure. There's a commonly held belief that Type F ATF is the best oil to use in a Bul clutch. My testing showed it was no better than any other ATF, and all of the ATFs gave less holding capacity than a non-friction-modified engine oil. The best I tested was Castrol Power 1 4T 5w-40.

Oh I've ridden one - my 199 has a hiboy frame and I like it very much. Which made Nigel's comments all the more surprising. It's an ex state championship winner so must have been considered viable at the time by someone. One thing I have noticed though - and I guess this is due to the lack of tubes under the engine - is that you really have to check the bolts in the engine mounts and skid plate regularly and keep them tight. Which makes sense seeing as they are tying everything together. The other thing I noticed was that the engine vibration is more noticeable if the head steady is loose/cracked/missing. I like your additional front steady - anything that helps tie this area together has to be a good thing - and will try one myself.

Is the turnbuckle part of a front head steady?

How do the Miller hiboy frames compare strength-wise to the factory frames?

If you do a web search you'll find lots of people saying things like "I put a set of Boyesens on my bike and now it's so much crisper and sharper!" The trouble is that in most cases the Boyesens were used to replace old battered reeds that no longer worked as well as they once did. To really test them properly you'd need to make back to back runs with new factory reeds. I don't have any TY specific experience but I've tried them on other bikes and prefer to use fresh OEM parts.

You mean the German Iwis chain? I use that as primary chain in my Metralla, very high quality. I'll look into it, thanks.

Thanks for the suggestions, it sounds like I just need to spend a little more money on a heavier chain than the standard DID MX chain I'm using now. I ride a lot, and always in very steep country so all things considered the chain and sprocket life probably isn't too bad. I'll try one of the better quality chains suggested.

What's a good chain for my M199 that I won't have to adjust constantly? I ride pretty regularly, every weekend if I can and find that I'm always having to adjust the chain. Any particular brand and model stand out from the rest? The DID I'm using at the moment is reasonable but I'm still having to nip it up frequently. And yes, I do keep it clean and lubed...

It's big enough, but only if used with the small KTM 9.5mm master cylinder. And of course anything you can do to reduce the amount of spring pressure required - eg. better plates and clutch fluid - will also help.

I've been using it for a year or so and try to ride every weekend. As you say, the downside is that in a lot of places it won't be acceptable. But if you can get away with it the action is beautifully smooth.

Most of my riding time is spent on my M199 Sherpa T 350, and like most older bikes it suffered from a heavy clutch action. It was especially annoying at those times when I wanted to use the clutch with one or two fingers and use the remaining fingers to grip the bars. What I did was machine up a stainless steel slave cylinder with a bronze piston and an automotive cup seal and fitted this to a modified side cover. Stainless slave cylinder and piston Slave cylinder in engine sidecover Back side of slave cylinder in (filthy) sidecover This is an easy mod, and for anyone interested in duplicating it the slave cylinder is 7/8" bore, 25mm OD and 32mm long overall. The open end has a 2mm wide x 28mm shoulder that locates the cylinder against the side cover, while the closed end is drilled and tapped to take the hose fitting. All that's required to fit it is to drill a 25mm hole through the side cover, centred on the original clutch pushrod hole. The back side of the opening may need a little filing to square it up so that the shoulder seats squarely against the case. The slave cylinder can then be Loctited in place. The best master cylinder to use is a Magura 9.5mm (from a KTM for example). The difference this made in clutch feel was remarkable; it's much much lighter. Just keep in mind that the Magura m/c will probably have seals meant to be used with mineral oil, while the standard 7/8" slave seal will be made for conventional fluid. You can get around this by using silicone fluid which is compatible with both. Clutch/primary drive fluid also plays a part in this - there are fluids that work much better than the usual type F ATF. The best I've found was Castrol Power 1 Racing 4T 5w-40, a non-friction modified motorcycle engine/transmission oil. It allows the use of slightly less spring pressure without slipping than ATF.

Flywheel weight is a compromise between traction and responsiveness. I experimented with various weights with my 199 Sherpa and was surprised at how much difference it makes. With too little weight it was very difficult to make it up some loose-surfaced climbs that previously I could make quite easily with the full flywheel weight. I also found that it was much more tiring to ride in those conditions as it just took so much more effort and concentration to keep the tyre hooked up. I eventually settled on just a bit less weight than standard, though this choice will obviously vary between riders and bikes. I think I'd err on the side of too much weight though - a slightly softened response I think would cause fewer problems than a lack of traction.

But some nice old Buls and a touching story - I really enjoyed this: