advance unit springs

LOUD MOUSE · Post by **LOUD MOUSE** » Tue Feb 09, 2010 5:48 pm

I mentioned the Neoprene as ya had stated you didn't know where (I have never seen neoprene on a cam sprocket) it was so I mentioned the location and reason which I added Clack-Clack to describe the sound one hears if it's been removed (carb cleaner/heat) and I'll now mention it can also be confused as being loose rivets also. ..............lm

teazer wrote:Thanks, I was struggling to interpret the pior post. No harm, no foul as they say.

teazer · Post by **teazer** » Tue Feb 09, 2010 5:53 pm

LM,

Thanks. I see where the neoprene was. But I have never seen that on a motor. Is that one of your upgrades, or is that a common change?

I've never seen it and it rather surprised me using a soft material there.

LOUD MOUSE · Post by **LOUD MOUSE** » Tue Feb 09, 2010 6:00 pm

It's a HONDA design to keep the Clack-Clack sound as the engine runs.
Near as I know it's been on all cam sprockets from number one.
Put that part in carb cleaner or flame and you're finished as I'm not aware of anything to replace it. ............. ............lm

teazer wrote:LM,

Thanks. I see where the neoprene was. But I have never seen that on a motor. Is that one of your upgrades, or is that a common change?

I've never seen it and it rather surprised me using a soft material there.

teazer · Post by **teazer** » Tue Feb 09, 2010 10:53 pm

Wow. I have had multiple CB72/77 motors and even bought a box load of cams and sprockets and have never seen one with that neoprene or whatever it is on it. Some early, some late, but never saw one like that.

Learn something new every day. I wonder if that was a US market thing. I only stripped three or four of them and they were early models, so maybe it was a later change. I'll watch out for that .

LOUD MOUSE · Post by **LOUD MOUSE** » Tue Feb 09, 2010 10:55 pm

Like I stated earlier they were all that way.
Can't ya imagine the sound when it's gone.
I have heard it. .............lm

teazer wrote:Wow. I have had multiple CB72/77 motors and even bought a box load of cams and sprockets and have never seen one with that neoprene or whatever it is on it. Some early, some late, but never saw one like that.

Learn something new every day. I wonder if that was a US market thing. I only stripped three or four of them and they were early models, so maybe it was a later change. I'll watch out for that .

teazer · Post by **teazer** » Wed Feb 10, 2010 12:54 am

And yet here is one on the desk beside me with no sign of that rubber stuff. Weird eh.

This one is in almost perfect condition with no slack in the advancer, so I don't want to pull it apart. Hang on. I just took it out to the shop and examined it under a brightly lit magnifying glass and it's interesting.

It looks like it has a back coating around the pegs, but when I tried to poke it with a scriber, it turns out to be as hard as the steel underneath. As best as I can tell, there is indeed something there, but it's almost like a black coating of something. It does not appear to be a thick soft coating, but almost like a layer of paint - in terms of thickness.

That probably explains your earlier comment about it potentially being destroyed by carb cleaner or heat.

Now I'm tempted to pull that one apart just to see exactly what it is, but this one is too good to waste.

That's very interesting.

And this one has both O marks, on the sprocket and the splined center section.

LOUD MOUSE · Post by **LOUD MOUSE** » Wed Feb 10, 2010 7:48 am

The coating (neoprene?) isn't very thick but ya can get a better look at it if ya by accident put the part in carb cleaner.
Ya can then get a first hand look at it when ya scoop the 2 little black things out of the cleaner. ...........lm

teazer wrote:And yet here is one on the desk beside me with no sign of that rubber stuff. Weird eh.

This one is in almost perfect condition with no slack in the advancer, so I don't want to pull it apart. Hang on. I just took it out to the shop and examined it under a brightly lit magnifying glass and it's interesting.

It looks like it has a back coating around the pegs, but when I tried to poke it with a scriber, it turns out to be as hard as the steel underneath. As best as I can tell, there is indeed something there, but it's almost like a black coating of something. It does not appear to be a thick soft coating, but almost like a layer of paint - in terms of thickness.

That probably explains your earlier comment about it potentially being destroyed by carb cleaner or heat.

Now I'm tempted to pull that one apart just to see exactly what it is, but this one is too good to waste.

That's very interesting.

And this one has both O marks, on the sprocket and the splined center section.