Hi Carl,
I would reckon the valves have never been calibrated to be honest and now that you mention it, it would seem like the most likely cause. I do not know the clearances despite seeking info on the net. The carb sits neatly and has no fault as far as I can see other than the butterfly valve was a bit stiff when I got the bike. It was actually a build up of crud as the previous owner had the removed the filter (a sponge sock ) and also drilled holes in the ait filter housing.... presuming in an attempt to increase airflow and thus hp... Which reminds me.... must pick up a proper airfilter for it..

If anyone has the valve clearances for the Zongshen 250cc motor and also the oil quanity for a complete fill and change it would be much appreciated . I am guesing that 1 liter should do it but will probably put in 750ml and run it hot and then top up if I feel it is needed.

Just back from a spin in a sand and rock quarry up the road from my house.... as basic as the bike is..... it really is a lot of bloody fun and a great way to learn to handle the rouh stuff..... It is my first dirt bike and would like to keep it in good shape

Another thing you guys may be able to help me with, on the rear swing arm (chain side), there is a rubber mount that sits on top of the arm. This 'strip' of rubber acts as a guide for the chain on the return back to the drive sprocket so that the chain doesn't rub off the arm....... Erm... what is it called and where can I get a replacement?? I have asked the Swedish dealer for the bike but he hasn't a clue what i am on about... Is there a technical name for this item or will 'super-duper-rubber-mounty-thingy-for the chain-rear-swing arm-protector' do...

R: