Technical Bulletin - Crank and Flywheel Nut

[rodent]

I picked my scooter up from the dealers after having the "correct" nut fitted, the mechanic told me that the there is actually nothing wrong with "incorrect" nut and it is exactly the same as the "slotted or black" nut.

He went on to say that allegedly the problem was just that the nuts were not torqued into place properly at the factory.

Your mileage may vary.

PS: On my bike the nut cannot be seen through the oil level hole with oil in the bike.

Edit: I took my bike off the trailer leaned it over to the left to let any oil drain away, and yes you can see the nut through the oil level hole. It's toward the upper left.

 

[yowie05]

Took my bike in to dealer 4 weeks ago tomorrow. Still no word on when I'll be getting it back. If you can get the nut yaself I would do that.

 

[Doc Brown]

I bought a new EC 300/19 last week and asked my dealer if the nut needs to be checked but he said no.

He said its a later 2019 model and it is not affected. How can he know? Do they have a list with VIN numbers. I doubt he tells the truth...

 

[Anders]

If you read the pdf attached to the first post, you will find the list of VIN numbers

 

[Doc Brown]

If you read the pdf attached to the first post, you will find the list of VIN numbers

Thanks Anders, I somehow managed to miss that one...

 

[Doc Brown]

I picked my scooter up from the dealers after having the "correct" nut fitted, the mechanic told me that the there is actually nothing wrong with "incorrect" nut and it is exactly the same as the "slotted or black" nut.

He went on to say that allegedly the problem was just that the nuts were not torqued into place properly at the factory.

Your mileage may vary.

PS: On my bike the nut cannot be seen through the oil level hole with oil in the bike.

Edit: I took my bike off the trailer leaned it over to the left to let any oil drain away, and yes you can see the nut through the oil level hole. It's toward the upper left.

My new 300's VIN belongs to the affected lot

So what you are saying is I can see the nut through the oil level sight glass if the oil is drained ??? You mean I can see it and identify if it is the correct one ???
Pls let me know asap.

edit: is it a normal nut or a left hand threaded one (tightening counter clock wise) ?

 

[rodent]

My new 300's VIN belongs to the affected lot

So what you are saying is I can see the nut through the oil level sight glass if the oil is drained ??? You mean I can see it and identify if it is the correct one ???
Pls let me know asap.

edit: is it a normal nut or a left hand threaded one (tightening counter clock wise) ?

Yes you can see it through the hole, just lean your bike to the left to let the oil drain away and the nut is to the upper left. I can see that mine is silver with the "LHT" marking cut out of the corners. So if it's black or silver with the cuts it's correct, yes it is a LHT.

As I said above, the dealer told me that there nothing wrong with the "wrong" nut, it's just that it may not have been tightened to spec when assembled.

 

[Doc Brown]

Yes you can see it through the hole, just lean your bike to the left to let the oil drain away and the nut is to the upper left. I can see that mine is silver with the "LHT" marking cut out of the corners. So if it's black or silver with the cuts it's correct, yes it is a LHT.

As I said above, the dealer told me that there nothing wrong with the "wrong" nut, it's just that it may not have been tightened to spec when assembled.

Rodent, you really made my day. Thank you so much! It makes it easier for me. I will check this tomorrow with a strong flashlight. Yep, if its black or silver with cuts its okay.
I'll report back!

Thanks again !!!

Doc

 

[shawbagga]

I believe it was excessive clearance on threads making them not tighten correctly/loosen easily also.

 

[rodent]

I believe it was excessive clearance on threads making them not tighten correctly/loosen easily also.

Do you know that 1st hand? Guy who did mine told me they were the same.

I never had both nuts in my hand at once(well you know what I mean) so I cannot confirm, but I have known this guy for many years and I am confident that he not mistaken.

If someone has both I'd love to hear their opinion.

 

[RudolfHucker]

I believe it was excessive clearance on threads making them not tighten correctly/loosen easily also.

That is the case. On the video I saw, you can see that the nut can be rocked when on the thread. I changed mine and although the original was tight, it was a lightweight job that seemed pretty flimsy.

 

[rodent]

That is the case. On the video I saw, you can see that the nut can be rocked when on the thread. I changed mine and although the original was tight, it was a lightweight job that seemed pretty flimsy.

Did you measure or weigh them? Did you check the threads with a thread gauge? Do you have pictures of both together for comparison?

 

[Doc Brown]

@Rodent: my dealer confirmed what you said. I called him today and said that when I looked through the oil sight glass I only saw a silver nut but no cuts on its edges.
He said dont worry, the nuts were not the problem, they just forgot the Loctite 648 on them and did not torque them properly.

He will sent me a written confirmation that he has checked/secured/torqued the nut and has filed a warranty claim to GasGas, he will also send me the worksheet and the warranty claim. So I guess I can relax...

If the nut is left hand thread how the hell can it get loose/off when the crank spins forward?

 

[RudolfHucker]

Finally found the still photo of my original crank nut. It is marked as loctited and it was solid.

 

[Doc Brown]

Finally found the still photo of my original crank nut. It is marked as loctited and it was solid.

Thx for the photo. If it was tight and installed with Loctite I guess it was okay? Did you replace it?

edit: I saw you replaced it...

 

[RudolfHucker]

Yes, I replaced it as the UK importer said it needed to be done due to the OEM nut being lighter material and he supplied the replacement.

I have found the video I mentioned but I can't find a method of attaching it to a post and I don't have an online photo store.

 

[Doc Brown]

Yes, I replaced it as the UK importer said it needed to be done due to the OEM nut being lighter material and he supplied the replacement.

I have found the video I mentioned but I can't find a method of attaching it to a post and I don't have an online photo store.

If you email me the video I could try to upload it to my YouTube channel.

However, I just ordered the new nut and the gasket for the engine cover. I don't trust the dealer so will replace it and then I can be 100% sure that it has been done properly.

Thanks again for the photo !

Doc

 

[Doc Brown]

@RudolfHucker

I fear its required to remove the clutch basket otherwise it wont be possible to put a socket on the crank nut, right? If so how can I block the crank so it does not turn when I torque the crank nut?

 

[RudolfHucker]

You don't need to remove the clutch basket, I didn't.

I used a Motion Pro gear jamming tool, a 6 point socket and a 1m socket bar (very carefully!) but my mate used a soft penny coin just as successfully.

 

[Doc Brown]

Thank you for the info. Good that I dont need to remove the clutch as I dont have the safety washer.
Like yer mate I will use a 5 (or2) Euro cent coin to block the gears.