2011 GasGas EC300E Nylon Crankshaft Counterweight bolt problem.

[Westd]

Hi there, Just wanted to see if I could help others avoid mangling their engine by explaining a recent problem I had with my 2011 Gas Gas EC300E.

Went to start the bike with the button and it turned over a few times then stopped cranking abruptly!

First thought starter motor was jammed, tried to kick start it also jammed solid , would not turn over.

Put it in gear and pulled back and forward to see if I could release what I thought was a jammed starter motor, would not release.

Back on the trailer!

Got it home pulled apart the following (in sequence):

1. Starter motor out, nothing wrong, still wont kick over with Kick Start (solid)
2. Flywheel cover and fly wheel off, nothing to see here, all ok.
3. Remove Spark plug, to make it easier to rotate (no Compression).
3. Clutch cover off, no broken teeth or jam ups I can see here.
4. Take off clutch (to see if it was a problem is in the gear box or crank related), gear shaft turns freely, gears all work whilst rotating shaft.
5. Try to rotate crank from the retaining nut with socket and ratchet, no movement ?
6. Take of exhaust look in through exhaust port - all looks ok.
7. Again move crank "back and forward" with socket and ratchet on crank retaining nut, after a couple of goes I get "crank movement" back and forward, but then locking at eack point about 180 degrees?
9. Take of tank, radiators, head and barrel, no damage to be seen?
At this stage I am perplexed , what the F***???

Crank is now turning back and forward by hand to a "lock point" at 180 degrees, I decide to put a magnet in between the crank halves to see if it will pick anything up.

A screw (slightly bent) comes out with the magnet, now the crank is freely turning again full rotations.

How the hell did that screw get in there !, only one way in (in my mind) through the aircleaner / carby, but how, I am too careful for that to happen, right??

To bring this saga to a close I start feeling around in the gap between the crank halves with my finger, and one of the nylon counter weights (some times refered to "Stuffers") is wobbly, and I can "now" see a screw missing near the conrod.

I though I might be able to get another screw in (as there was no damage) but gap between halves dont allow for it.

End of this story, I will need to split the caseings and crank to install and "loctite" new nylon counterweight retaining screws in ..... "AAAHHH!".

Now, this bike has never had the bottom end apart from new, and is in like new condition even though it is 10 years old (i have owned it from new).

I just wanted to put this post up just in case this happens to others, so you know where to look first, finding the problem was frustrating, as there was no visual evidence of damage!

I guess "I am lucky" as it happened whilst "cranking it over" to start it before it was running (less chance of damage to components if it was at high revs), but I dont feel lucky, as this did not need to happen if the screws were "loctited in" when the thing was assembled!

I would suggest checking these screws for "Looseness"during top end rebuilds, "Yes I know you cannot get to them all from the top", but if those you can get to are "loose" then the others are likely to be the same.
As much as it sounds outrageous, if these screws are loose, the crank should be removed, split and screws refitted with loctite.

A screw/s coming out at "revs" has the potential to turn your motor into a mangled mess, costing you big bucks.

Hope this helps

D Dub
Australia