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2017 exc 450 sputtered and died.Questions

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I recently had a problem with my bike,the issue was solved but I want to share it to help other and maybe get people to pay attention.

So i was out riding and fell in a hill,when i tried to start the bike it was completely dead.No horn,lights,starter nada. After 5 min of thinking about pushing the bike to the nearest rode I tried to start it and it turned over and started and ran perfect.I thought i had activated some kind of tip over safety feature and didnt think more of it.

Next time out riding i stopped the bike by kill switch,talked with a friend and same thing,bike completely dead.Thought again i had activated some kind of safety feature somehow,after a while the bike started like normal again,continued riding when I noticed the engine started to loose power,then it started to sputter like it was running out of fuel,and eventually died.Pushing the starter button did nothing,after a while bike could be restarted again,but it would not run for long before repeating the symptoms described earlier,manage to limp the bike back to the car although it died on me a dozen times.

I found both battery connections tight although corroded,also the washers for the screws were missing.The main problem was were the ground cable bolts to the subframe,it was only finger tight and aluminium oxidised .The subframe is aluminium,aluminium itself is highly conductive but it builds up a aluminium oxide layer when exposed to air,this layer is not conductive and will cause alot of resistance,its like the aluminium builds up a non conductive plastic layer on itself.I see it all the time while welding if the aluminium is not cleaned where the ground attaches to will cause all sort of problems and arcing between metals.I cleaned all the  contact surfaces and reattached everything and the bike was back to normal and starting better than ever.

I would suggest people clean these terminals and apply dielectric grease to stop oxidation. Im also contemplating on making a separate ground wire from the battery to the engine,its possible to get a resistance problem between the frame and subframe, at least in theory.

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I found both battery connections tight although corroded,also the washers for the screws were missing.The main problem was were the ground cable bolts to the subframe,it was only finger tight and aluminium oxidised .

This will continue to be an issue until owners add grounding from the Battery to Frame to Starter. Covered with shrink wrap & connected with 1/4" eye connectors. About 30" of material.

 image.png.6d1b39f4fbab71c1ad93c22d56c655fc.png

Happy grounding

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I actually redid all the terminals properly today,also put dielelectric grease as i didnt have any at the trail.Found the ignition coil ground quite corroded as well as the frame ground under the tank and it was only finger tight,cleaned them up,greased and then I ran a new ground wire from the battery to the frame ground terminal.I might do the suggested extra ground to the engine/starter as you suggested.

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