Topic: 78 750F Sprocket Play

[ZanVooden]

So recently I was on my 78F on my way home from Road America. I noticed my chain seemed a little loose and I noticed a kink in chain links. I stopped by a friends place, and tightened the chain a bit and worked the stuck links enough so they would move easier, and figured I would limp the bike home to my shop.

Unfortunately disaster struck and the chain broke on the highway. So I hauled the bike home in the back of a pickup and just recently got around to fixing it.

Luckily there the chain did not break the engine cases, just mangled the chain guard, broke the rear turn signal and scratch a few things.

So new chain and sprocket go on. New chain guard, and turn signal as well as new rubber cush drive dampers.

Tighten the chain with somebody sitting on the bike. Then go take it out for a test ride just to be sure everything is fine. As I'm riding it I can hear a knocking noise coming form the lower cases, so I bring it back in and pull the front sprocket cover off.

There seems to be a lot of play in the sprocket when in gear.

This doesnt seem normal so I thought I'd post here for some help.

Hopefully these videos show how much rotational play the front sprocket has when in gear. And in the second video you can hear the noise.

[brandEn]

You sure its just not chain slap from the chain being to loose?

[ZanVooden]

That was what I thought at first. But I cant see anywhere the chain would be hitting. These videos were when the bike was on the center stand, so maybe I'll try tightening the chain to see if the noise goes away, and proves I'm just crazy and a bit paranoid...

[brandEn]

The chain looks REAL loose from your video. Take it for a spin around the block and run it through the gears.

[shinyribs]

IMO that is typical tranny slop. I have a '76F (42,000 miles) and a 78K(33,ooo miles) they both have the same amount of slack as yours. As you shift from 1st to 5 th gear (bike off) you will notice that the slack decreases/increases with the gear reduction. Crazy,I know.

Also,your chain does look awful loose. I would take a look at that. You can actually see it falling off the bottom of the front sprocket. Careful bud!

If you set your chain tension with the rear suspension squatted under rider weight it will cause a super loose chain otherwise. The point of the slack is to allow for suspension travel causing tightening/loosening of the chain. It's really best to set the chain rider off/on the side stand. JMO,please dont fuss at me if anyone's opinion varies.