So, a mystery then as rain could not have a permanent effect on the plug.

The advice would appear to be normal but I have found no difference in running if I start up then ride off after a few moments.

I found that when I ran the bike in the garden without letting it warm up the plug failed - this happened a few times but not since letting it warm up before riding....

If you find that the bike is missing from not letting it warm up properly don't try and rev and clean it out like a 2 stroke- this makes it worse.

just park it up running on tick over and it will sort itself out after 5 mins or by the time you walk the first section.

if i remember right back when montesa 4rts came out they said to start bike let run for 5 min to allow it to adjust to your climate and elevation changes if you ride the same are area all the time your pretty well set . 

On 3/6/2017 at 1:21 AM, ianwilson said:

Have you tried the ECU reset. Full throttle open / keep kill switch pressed and 3 kicks on starter. Then start as normal. Unlikey be water ingress they are very well sealed.

Hello.. i have this problem.. the ECU Reset only work if i connect 12v battery.. do you have any idea? I put extra capasito 10.000fart 50v Also doesn’t work only work if i put battery..

What solved the problem for me was to service the bike every 15 hours in summer and every 10 hours in winter and warm up the engine (Until the fan comes on ) before riding off.  The bike seems sensitive to regular plug changes. 

I once dropped the bike into a stream- fully submerged it and even after it was dried I had problems with sudden cut outs, even 2 weeks after the dunking. After a service (new plugs) no problems.  There was no water in the oil or petrol so why the cut outs remains a mystery.  

So first call with any problem is change the plugs.