Sprocket in engine won't turn

GoldenMotor.com

adamrdiamond

New Member
Jul 27, 2011
2
0
0
San Francisco
I am putting my engine together on my bike and am at the stage where I place the clutch cable through the spring, attach it to the clutch arm and then I am supposed to engage it and spin the sprocket. The sprocket won't move even with a lot of force. When I engage the clutch are it feels like there is no tension against anything at all. Is it even engaging? I know I can either engage it with the cable and clutch lever or just engage it manually. I just don't feel like it is doing anything when I push it manually. Please help.
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
First let's get the terminology right. Engaged means the sprocket is connected to the engine crankshaft by way of the clutch pads, pressure plate and gears.

Disengaged means the sprocket is free to rotate by itself and not connected to the engine crankshaft.

Now, most new comers will seriously underestimate the amount of force required to disengage the clutch (move the clutch actuator arm in far enough) It's very difficult to move that arm with your bare hand, especially on a new engine. Connect the clutch cable with as little slack as you can get it and try that.

If you still have problems the clutch friction pads might be stuck. Not uncommon on a new engine. Usually a good solid push on the clutch actuator arm, wrap a rag around your hand to do this, will break the sticky parts. Some require a sharp rap with a soft hammer against the pin which protrudes from the center of the sprocket. DO NOT start adjusting on the right side of the engine, (flower nut) until you have tried all of the hints listed above. Let us know what you find.
Tom
 

adamrdiamond

New Member
Jul 27, 2011
2
0
0
San Francisco
Tom,
Thanks a lot. I got a little excited and kept going forward before I got your reply. In hine sight I did not realize the amount of pressure that needed to be placed on the clutch lever. I ended up taking off the cover on the other side of the engine, removed the flower nut and rotated the plates which were a little stuck. I put it all back together, got the clutch to move nicely now I just need to put the chain on and hopefully it will run. 2 bad things though. The first is I had no idea what tool I needed to remove the flower nut. I know I used the wrong tool but I had nothing else. That's right I used pliers. I got it off and was able to put it back in what I think is the same position. I scraped it up a bit but it seems ok. What happens if the flower nut is to tight or to loose? What tool do you use to get it on and off? What symptom would I see or hear that would require and adjustment to the flower nut? How much do you adjust it?
Problem 2: The frame of the bike is to big for the engine. I was able to mount the front part of the engine to the frame but the rear mount is about 3 inches away from the frame. Any ideas.
Thanks for all your insight. It's much appreciated.
-Adam
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
Adam,
We usually recommend that you mount the rear of the engine first then worry about the front mount. The seat tube on most bikes will readily accept the engine mount but due to the differences in frame design/size the front mount can present problems. There are aftermarket mounts but many of us fabricate our front mounts. Try using the search feature at the top of the page, type in, 'mounting' and you'll have lots to read on the subject.
Some 'V' frame bikes will require no modifications at all but most cruiser style bikes with a curved or oversized downtube will need a little imagination and work to get the front mounted solidly. Do not try to use any resilient material in the engine mounts. You'll want it as solidly mounted to the bike frame as possible and with no gaps in the mounts.
Good luck. Keep us informed of your progress and we're always here if you need more help.
Tom


Edit: Just reading through your first post I saw where you said you ran the clutch cable through the spring. We always suggest that you do not use the small spring that comes with the kit and use only the larger one which is really just a heat shield between the cable and the cylinder. The small spring will do nothing but increase the force needed to disengage the clutch from the handlebar lever.

Tom
 
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