Broken down in South America, I need help diagnosing my problem
--------------------------------------------------------------------------------
Hello, I'm new here (site recommended to me) so be gentle
Problem: Motorcycle turns over but won't start
Motorcycle: BMW F650 GS Dakar 2006 US import
Background.
The motorcycle now has over 60,000 miles on the clock
NB: To date I have not checked the valves/shims neither have I replaced the fuel filter
I have just ridden through Brazil where the quality of fuel is very low, possibly as low as 85 RON and I think it has a percentage of ethanol in it too. When I entered French Guiana and filled up with high quality fuel I immediately got over 30% more mpg. I was very happy!
In Brazil I had poor mpg, and I sensed that the bike had become sluggish in nature – it no longer had the same acceleration or torque, made me realise that I should get the valve clearances checked. I am aware that I should have done this sooner. Having never done it before I've been putting it off until symptoms like back firing occurred. I was hedging getting to Suriname or Guyana before doing it but I have now broken down. The bike hasn't been backfiring and the mpg and sluggish nature improved with the better quality fuel in French Guiana. I've not noticed any particular problems with starting the motorcycle.
Two days before I broke down I was riding in 3rd/4th gear and the bike surged and perhaps briefly cut out two of three times betwwen 3,500 & 4,500 RPM. When I stopped and switched the engine off I had problems restarting it. I could hear the Moditec unit making a whirring noise in between starts and I allowed 5 or more seconds before hitting the ignition button again. In between the starts I noticed that the rev counter would flick up in time with a noise form the Moditec unit and I assumed it was calculating air/fuel mixture etc. When I got home I reset the Moditec unit by disconnecting it for 20 minutes. Following this the motorcycle restarted on the third attempt and I observed what I consider to be normal behaviour as it calculated the air/fuel mix between each start.
The following day I went out on the motorcycle for an hour and stopped for 10 minutes. When I tried to restart the bike it wouldn't fire up. I eventually got some help bump starting it and all was good but I was now more concerned. When I arrived home I switched it off and it restarted immediately first time.
The next morning the motorcycle wouldn't start at all. It turns over but doesn't fire up. When I turn the motorcycle on I no longer hear any noise from the Moditec unit and it no longer appears to be doing any start up checks. The rev counter remains at zero in between restarts. The motorcycle wouldn't bump start, and I even got a very slow tow to see if it would start but the rear wheel just locked up and it wouldn't fire up.
I have checked the wiring loom, battery connections, air filter, all appears good. I have plenty of oil and there is fuel in the tank.
My thoughts are:
Valves... have I ****ed up my engine?
Are the fuel filter, pump or injector needles ****ed from the poor fuel in Brazil
Is my Moditec unit ****ed
Is the Brazilian fuel problem a red herring?
Thanks for your help.
