Engine Drive Suddenly Uneven Problem


Irish John

My Huang Shen & Grubee frame mounted motor runs OK for many miles then suddenly it starts to drive like the chain sprocket is slipping. I though it was a broken key on a shaft but both keys are fine. I think it might be the centrifugal clutch although it feels like the drive sprocket shaft. I wonder could the engager be causing problems. I can't see how although it feels like its the engager. I've looked at the engager and it seems fine. I've looked at the clutch and it too seems fine. I don't think its fuel or carby. I have a filter but maybe it is the carby. There's no water in the fuel. The line has air bubbles but should that matter?
Anyone had experience of this. It feels very horrible when it happens - it feels exactly like there are a few teeth missing on the sprocket but they are all fine. gears fine too.
Any help gratefully received.
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Uneven Drive Problem Solved

Tonight on a busy freeway I solved the uneven drive problem. The motor was revving fine but occasionally starting to miss out on the drive - like it was engaging and disengaging alternately. I lost my temper and pulled the clutch in really hard to stop like a motorcyclist would. By pulling really hard on the clutch it engaged the engager really hard and this solved the problem.
Although it felt and it sounded like the engager was engaging properly it wasn't. I stopped and tightened the cable in the engager lever. It was so simple to solve but I just didn't think that was the problem. I pulled the gears apart yesterday to look at the shaft keys. I looked at the engager teeth and they looked OK. The whole mechanism for the Grubee engager\ disengager is a joke. It's back to front to the way human instincts work. HoughMade has fabricated a reversal mechanism so you let the lever out to engage it and pull it in to disengage it. This is the way it should have been designed but unless the spring to hold the engager in the engaged position is very strong I fear it isn't going to work well for long. My engager needs to be held in place by a strong force so the teeth don't slip. Anyway the problem with the rough drive behaviour is solved but a proper clutch/engager lever solution still needs more thought.
Mine is working fine reversed, but I am thinking of modifying it so that the engager cable comes in from the right side like it did before the reversal. I may not, however, because coming in from the left, it does not interfere with pedaling because I inserted the cable in a piece of copper tubing (left over from the dishwasher install) and bent it so the the cable is out of the way.

We'll see.

I am glad to see you solved the issue- I just love riding this thing around and I'm sure you do too.
HoughMade, I knew that dishwasher install would result in something cyclingly positive. Can you grace us with a good picture of it all with the copper pipe etc. Would an ordinary noodle from a bike shop not have been a better solution? I would have to use a very strong spring to hold the engager on the engagee so to speak.