i have a 247 montesa, complete rebuild i have good spark clean carb and plenty of compression,  wont start !!!

Usual checks:

Fresh petrol? Fuel reaching plug? (Is it wet after attempts to start?) Choke mechanism working? Ignition timing set correctly? Fresh spark plug, correctly gapped? Tried a bump start? 

Edited March 5, 20206 yr by cleanorbust

You'll also have a hole in your crankcase unless you move your kickstart lever round a bit. As it is it will move the internals round too far.  It should be more towards upright than you have it now  Googling for a picture should give you the right setup. Though I notice you have a later lever on it I would still check.

 

 

 

Edited March 5, 20206 yr by 2stroke4stroke

Does it have a spark at the ht lead ? Kill switch functioning correctly? Re cleanorbust carb float valve not sticking?

Edited March 5, 20206 yr by section swept

Any backfire ?    Is the spark properly timed ?   Maybe try putting 1/2 thimble of fuel down the spark plug hole. Good luck

thanks for the tips, buzy weekend for me then !!

 

Check the spark from the end of the lead to engine metal, if it can't make 5mm at least at kicking speed you have a problem, also try another plug, they can look fine out of engine but then under compression just die. Also with the plug out dribble a bit of premix into the plug hole, put the plug back in and give it a kick see if it fires at all.

On 3/6/2020 at 4:17 PM, misscrabstick said:

Check the spark from the end of the lead to engine metal, if it can't make 5mm at least at kicking speed you have a problem, also try another plug, they can look fine out of engine but then under compression just die. Also with the plug out dribble a bit of premix into the plug hole, put the plug back in and give it a kick see if it fires at all.

 

seems that i don't have much of a spark, tried new plug , same as before, looking into the coil next, thanks

Lots of ignition/spark problems are caused by a bad earth, check that first. Was so on my 247. Changed everything but the earth lead, when I finally did, put all the old kit back.

 

replace the points and condenser 

I put Electronic Ignition on mine, best money I spent. Starts & runs perfectly now.

On 3/11/2020 at 4:43 PM, MartinH955 said:

I put Electronic Ignition on mine, best money I spent. Starts & runs perfectly now.

Yup, me too... I did the rounds trying to optimise the standard ignition and fuelling arrangement on my 247 and I mean, BIG TIME - timing set-up, condensor relocate, HT lead and plug replacement, points swap, air leak check, crank seals, carb strip and rebuild, fuel line replacement, the list goes on and on and on!. It simply refused to start, nothing, not even a suggestion of firing-up!

Threw the towel in eventually and on the advice of a fellow TC 247 owner, made the call to Electrex World. Two hours of installation time and TWO kicks later (with the aid of a decompression lever, again on the advice of another TC enthusiast) and... perfection. Starts now second kick EVERY time, with a lovely even idle, perfect pick-up and no drama, whatsoever, even after months of not being used! It's the single most effective improvement I've made to the 247 and one, without which, I'd have likely sold it on as a project and bought something newer!

 

 

Edited April 1, 20206 yr by riffraffretro

Condenser, are the contact (points) faces blue colour....indicates condenser faulty.  

Check that contacts open and close freely.....the pivot bush can dry and grip the pivot post causing opening and slow to no closure.

On 3/11/2020 at 4:43 PM, MartinH955 said:

I put Electronic Ignition on mine, best money I spent. Starts & runs perfectly now.

Same here..........