Yose 350W not engaging after left standing

[Jaypeedee]

I have had a Yose 350 700C rear wheel kit fitted for a bit over 4 years now and it has covered about 1K miles with no problems and was a godsend to get me out into the countryside in lockdown. Just recently it has developed a fault in that after being left standing say overnight it does not respond to the pedal sensor when I start off and if I press the hand throttle either nothing happens or the motor spins but does not engage. If I do this a few times, sometimes while pedalling as, well the motor engages as it should rather than spinning free and there is response to the pedals turning. Mostly this is then OK probably for the rest of the day but sometimes the problem recurs. Unfortunately this leaves me reluctant to risk going far from home as sometimes it takes a while to nudge it into operation.

I have undone and checked all the connections and checked the alignment of the pedal sensor and disc. Any suggestions as to what is going wrong and how to fix it.

 

[saneagle]

If the motor is whirring and not driving, the internal clutch is stuck. If the motor doesn't whirr, the problem is elsewhere. Which of the two is it - the first, second or both?

If you ever get water in the motor, then leave it, the clutch goes rusty and sticks. I'm not saying that's it. We need more information to make a proper diagnosis. Also, which way does the cable exit the motor axle - upwards, downards or sideways?

 

[Jaypeedee]

The motor whirrs but does not engage though after several tries it does seem to engage OK and then generally continues working OK for the rest of the outing but sometimes recurs. Your suggestion of sticking clutch does seem to fit and that would explain why blipping the throttle means it then responds to the pedals if it frees the clutch. The cable comes out at almost 5 o'clock. Any help how to fix this very much appreciated.

 

[esuark]

Had a similar problems with my Bafang SWX02 hub after 6,000 miles. Turned out to be the clutch not working, stuck. Ordered a replacement from China and all OK now in excess of 10,000 miles. Took the old one to bits and I think the grease in it just hardened/thickened. Another member on here had a similar problem with a different make of hub and soaked his, in what I don't know to cure his. It is all here on this site somewhere. Good luck.......

 

[Nealh]

ATF should suffice to soften hardened grease without washing it out..

 

[saneagle]

The motor whirrs but does not engage though after several tries it does seem to engage OK and then generally continues working OK for the rest of the outing but sometimes recurs. Your suggestion of sticking clutch does seem to fit and that would explain why blipping the throttle means it then responds to the pedals if it frees the clutch. The cable comes out at almost 5 o'clock. Any help how to fix this very much appreciated.

The best thing would be to open the motor and put some 3-in-1 oil on the rollers in the clutch. I can guarantee that you have some rust in there. The oil will stop it reforming when you stop using it.

 

[Jaypeedee]

Thanks a lot guys. It looks as if we likely have a fix. It sounds as if the "clutch" is something akin to what you find in in a recoil starter for an outboard so I am familiar with them. The wheel is still on the bike and it is sort of usable for short journeys to local shops and because of other things on hand I might not be able to get to grips with it for a little while. Does anybody know if there is a photo or video to be found on the web indicating how I get inside it, and what will confront me when I do, or is it all quite obvious when you look at it? I suppose it is too much to hope there is a pdf workshop manual in english to be found anywhere?
I am a diyer with a have a go attitude but it is nice to have any advance info available

 

[Jaypeedee]

I have just been watching some YouTube videos and I see I was wrong about the clutch but if they all work along similar lines I now have a better idea.Will have to look see how easy it is to free up the rollers or if the whole clutch has to be replaced.

 

[Nealh]

Removal of the core depends on which hub you have , if it has the face plate fixing (six m5 screws) then removal is easy , if it has the hidden fine screw thread then a tool is needed to unscrew the joint.

For the former remove the freewheel or cassette, on the LHS remove all fixtures from the axle inclding any nuts inboard of the brake rotor.
On the RHS remove the six face fixing screws , the core should then come out.
(Some times one may have to tap the LHS axle end for it to pop out) , use a rubber mallet or wod block and hammer to tap it.

 

[matthewslack]

The fact that sometimes it works is good news for it being fixable by lubrication once access is gained.

 

[saneagle]

The fact that sometimes it works is good news for it being fixable by lubrication once access is gained.

Everything depends on which motor you have. Some pictures of both sides would help. If it's an AKM motor, you should sort it sooner rather than later. If it's the type with an enclosed clutch, the only thing you can do is replace the whole clutch because you cannot get in to lubricate them; however, that type is more likely to fix themselves without dismantling.

 

[Jaypeedee]

Thanks Guys. This is all really helpful and encouraging. I will have to get the wheel off and post some photos for comment. The Yose site shows a planetary gear assembly for an AKM motor but says it is 40teeth and out of stock. Elsewhere I can see numerous assemblies with 36 teeth at wildly varying prices. All looks do-able once I have it apart. If I can get the right part it almost looks more sure fire to replace than clean it.

 

[saneagle]

Thanks Guys. This is all really helpful and encouraging. I will have to get the wheel off and post some photos for comment. The Yose site shows a planetary gear assembly for an AKM motor but says it is 40teeth and out of stock. Elsewhere I can see numerous assemblies with 36 teeth at wildly varying prices. All looks do-able once I have it apart. If I can get the right part it almost looks more sure fire to replace than clean it.

They've used different motors. Only you know which you have. Until we do, we can't help you.

 

[Nealh]

My Yose hub is an early one and I believe it was I who introuduced the Yose kit to the forum some 8 years ago.
My hub came from the day's when KT 's were the control system used.
The early hubs weren't AKM but had no identifying maker to who it was made by.