Are you using the valve lifter to ease the engine over compression, then applying that famous "long swinging kick" to build momentum and fire her up ? If not, and you are kicking directly against compression, the clutch would have to be good to hold against that.
If you have the cover off the clutch primary (big decision in itself !!) then the first thing to do is to eyeball the 4 springs when you lift the clutch. They should all lift equally and squarely. If not, then they need to be adjusted so they do all lift equally and squarely. Its quite a balancing act as to how tightly you screw down on each adjuster too, you can't just tighten them fully, some travel has to be left for the clutch to lift when you pull the handlebar lever.
Have you checked too that there is slight freeplay in the clutch cable ?
If still no joy, then you may need to check the actual clutch plates for wear, and for being flat. If the inserts are worn away, or the plates warped, then that can cause problems. Having the correct number of plates fitted in the correct order is also necessary, there is no accounting for what some previous owners may have done ?! Have fun, hopethishelps...
True - but we are talking a 49 Model 18 here, so as oem equipment it would have had a Burman CP box and a 4 spring clutch. Thats how my 49 Model 18 came - very well worn, it must be said.
Note that the parts book lists a 4 plate clutch for the 350cc and a 5 plate for the 500. Its not unknown for previous owners to have fitted whatever they could find when something was worn out, so that may be worth checking for, if other avenues don't improve things ?
thanks all for the replies. I do use the valve lifter to try to find the sweet spot. I am reluctant to kick too hard for fear of it slipping through and damaging my old knee. I'll try today to apply all of this good advice
1949 AJS Model 18 1972 Triumph T150V 1973 Triumph TR5T 1980 HD FXB 2006 HD XL 2009 HD FLTRSE
We probably should have mentioned it earlier, but it might also be wise to drain off the chaincase contents, and replenish with the correct quantity of oil (I seem to recall engine oil, without checking). If the oil level is too high, or old and gluggy, if could well cause the clutch to misbehave.
Di you have a sidecar on this bike, I distantly recall something along these lines (?).