hi there my mate has just bought a montesa 348 i think its a 1976 model.

it was running fine until he noticed some fuel weeping from the idle screw so he thought it would be a good idea to nip it up!!!!!

he also tightened the mixture screw aswell.

now the bike wont start, it turned over when i tried bumping it but it just chugged for a second then died.

if anyone knows how many turns out the screws should be, i guess that it will be different from factory due to age and wear but if i could get it somewhere near i can fine tune it from there.

thanks in advance. d tomlinson.

I always start a turn to 1.5 turns out from full in on the mixture to start. Start the bike and warm it up and set the ticker just over idle so you can hear the difference in idle as you adjust the air/mixture screw. Adjust the air/mixture screw until you achieve the best increased idle, adjust in small incriments and pause so that you can hear the difference. Rev the throttle from idle so there is no bog and adjust/repeat until you feel the bike is reving clean. Each bike is different and has a "sweet spot" and this has been working for me over the last 30 years. At least it should get you started. I hope it works for you.

All the best,

Carl

i will give that a try mate thanks alot great help.

I was going to ask how to set up my carb on my montesa cota 200 but it has already been answered.

Could you please tell me which screw is which ie the angled screw adjusts tickover or mixture

Thanks Mark

The angled screw lifts the throttle slide for tickover and the horizontal screw is for mixture

Dave

Good info you have received here. However, if the 348 still does not run properly it is because the slide and the bore are worn out. They were made from the same material and their working life was not very long, You will need to have both parts recoed like I did on my 348 and the difference in amazing. If you live in Australia let me know as I have contact details for the bloke that did my carb.

thanks for the info everyone that would have been great belldane but i think the shipping from england would out do the price of new parts. ha. cheers everyone.