korider.com | Hyosung Motorcycle Owners Forum

korider.com | Hyosung Motorcycle Owners Forum

  • December 14, 2018, 10:29:30 PM
  • Welcome, Guest
Please login or register.

Login with username, password and session length
Advanced search

News:

Welcome to Korider.com!

Pages: [1] 2

Author Topic: Can you identify this noise in my 1999 Sense?  (Read 672 times)

VTPete

  • Training Wheels
  • *
  • Offline Offline
  • Posts: 9
Can you identify this noise in my 1999 Sense?
« on: October 13, 2018, 10:11:12 PM »

Hi All,
I recently picked up a titled 1999 Sense for $80.  After cleaning the carb, I have it running fine.
But, it makes a rattle noise that reminds me of metal against metal.  I checked the variator and it's not coming from there.
It speeds up as I rev up the engine.  At higher RPMs it goes away completely. 
It's a bit like if the magneto fan was hitting something on every revolution.  I haven't taken off the cover to look yet as those side panels are a pain to take off and on. 
Or maybe they just sound like this?
Here's a video of it.  https://youtu.be/D5KttpTyjN0
For speed, it's topping out at 30mph... doesn't seem to want to rev up as much on the road as on the stand.  But, I can deal with performance issues later.  What do you think?
-VTPete
Logged

Register and log in and the Ads below will be gone! :D

BikeBandit.com

VTPete

  • Training Wheels
  • *
  • Offline Offline
  • Posts: 9
Re: Can you identify this noise in my 1999 Sense?
« Reply #1 on: October 14, 2018, 08:52:01 PM »

I've identified the noise.  It's the main starter gear wobbling behind the front movable drive.  (Variator.)

I'm not sure why it's wobbling... it moves both forward and back and side to side a bit.  Under higher RPM, centrifugal force holds in one place.

Here's the problem though:  For the life of me, I can't figure out how to get the movable drive off to inspect the starter gear.  (Not the starter's pinion gear, the drive gear behind the movable drive.)  The shop manual looks like it's only a simple metal spacer, but mine won't budge, and when I tried a gear puller on it, I think I may have done more damage than good.

On the bright side, I unplugged the screw in the muffler and got another 10 mph out of her!  Wow!

Now, I may have really done a number on that variator.  How the heck do you get it off?
-Pete
Logged

umop-ǝpisdn

  • Global Moderator
  • Forum Addict
  • *****
  • Online Online
  • Posts: 7394
Re: Can you identify this noise in my 1999 Sense?
« Reply #2 on: October 15, 2018, 02:17:36 AM »

Hi pete,

I've no idea about the sense, as I do not have one, but have a look in the parts catalogue for better quality exploded views. Maybe it offers a clue?
Logged
I used to be a sensitive, new age guy, but times have changed and now I am more of a caring, understanding, ninties type.

VTPete

  • Training Wheels
  • *
  • Offline Offline
  • Posts: 9
Re: Can you identify this noise in my 1999 Sense?
« Reply #3 on: October 15, 2018, 04:25:27 PM »

The parts catalog and the service manual show nothing special.  Just a roller on the drive shaft.
We applied a lot of pressure using a cheap gear puller, but it just bent the arms of the puller.
We're picking up a three tong'd puller today.  I THINK it's just supposed to slide off!
I'm worried there are teeth on the inner side of the variator bell that are butting up against another set of teeth on the shaft.  But no such teeth are on the shaft in the diagrams except for those that hold the starter gear to the drive shaft... and the outer, immovable, outside half of the variator.

Question:  Is the movable side of the variator... the one that expands outward... fixed to the shaft, or does it freely rotate?  Assuming it's fixed to the shaft, the $64,000 question is HOW?  I'm guessing the back side slides onto the same teeth on the shaft that the starter pully attaches to.  I feel like I'm the only person on the internet who's ever tried to take this off as there are million videos of people getting the nut off, but none pulling off the actual variator on a Sense.  And I can find not a single repair shop that knows anything about them.

-Pete
Logged

umop-ǝpisdn

  • Global Moderator
  • Forum Addict
  • *****
  • Online Online
  • Posts: 7394
Re: Can you identify this noise in my 1999 Sense?
« Reply #4 on: October 15, 2018, 09:10:21 PM »

I think you're on the right track, as in with the puller. It'd be interference fit onto the shaft and has now become stuck. Heat perhaps? Apply heat to the variator and it will expand, heat while the puller has tension. Cool the shaft with a wet towel so there is less heat soak.
Logged
I used to be a sensitive, new age guy, but times have changed and now I am more of a caring, understanding, ninties type.

VTPete

  • Training Wheels
  • *
  • Offline Offline
  • Posts: 9
Re: Can you identify this noise in my 1999 Sense?
« Reply #5 on: October 17, 2018, 11:05:34 AM »

Ok, job done.  And, I might not have ruined the shaft nor melted any rubber parts on the crankcase seals.

Removing the variator's rear (movable) bell required destroying the variator.  We tried heat, penetrating oil and several types of pullers.

In the end, we finally removed the center bushing the variator spins on by putting my smallest set of pullers behind the back ramp plate and cranking.  Because the back ramp plate is made curved, the puller arms didn't have anything to grab onto, they would just expand outward as I pulled.  But, by wedging metal between them and the engine casing, we caused the center bushing to move out an 1/8 inch.  Yes, we applied a propane torch while doing this.

Once there was enough of a gap between the back plate and the starter gear, I put another set of pullers on it (larger) and ran several passes of strong brake cable wire through the holes in the arms of the puller to prevent them from expanding outward as we pulled.  Then it was just a lot of slow pulling.  The trick was to buy another set of pullers that fit better.  This of course deformed (warped) the entire variator badly, but a run-up of the engine later showed that the shaft seemed to still be nice and straight.

What was holding the center bushing on?  Rust!  The bushing is about 2 inches long and it was completely frozen to the shaft with rust.  I doubt the penetrating oil helped, but the heat applied likely helped.  The shaft looks like it will require very light polishing with some 000 steel wool to remove that light coat of rust.  (No pitting found.)

I ordered a replacement variator... the Morini AD50 one; I'm guessing it's a drop in replacement.  Hopefully.

In the end, the noise could have likely been fixed by simply tapping the center pushing in towards the center of the scooter to push the starter motor and rear variator plate against one another... but I didn't know that because I had no idea what the actual problem was.  (It was, in the end, a millimeter gap between them which allowed the starter gear to wobble at lower RPMs.)  In the end, I ran up the engine with no load (nothing attached to the shaft) and it sounded perfect.

So now I just have to wait for parts.  I hate that part!
Logged

spit051261

  • Grinding the pipes
  • *****
  • Offline Offline
  • Posts: 1261
Re: Can you identify this noise in my 1999 Sense?
« Reply #6 on: October 17, 2018, 12:11:14 PM »

What do you think?
-VTPete
What exactly did you expect for $80 ?  ::)
You could probably sell the lights for more than that and throw the rest away and still be in front  ;D
« Last Edit: October 17, 2018, 12:13:46 PM by spit051261 »
Logged
2010  GT650R in the best colour RED

VTPete

  • Training Wheels
  • *
  • Offline Offline
  • Posts: 9
Re: Can you identify this noise in my 1999 Sense?
« Reply #7 on: October 19, 2018, 01:30:41 PM »

What did I expect for $80?  A scooter with a completely frozen engine, locked up parts, flat tires...  I expected to find a parts bike.  I know it was a rhetorical question, but I wanted to be clear that I consider this the find of the year!
Logged

Joss

  • Scraping the pegs
  • *****
  • Offline Offline
  • Posts: 918
    • Website
Re: Can you identify this noise in my 1999 Sense?
« Reply #8 on: October 19, 2018, 01:44:21 PM »

I doubt the penetrating oil helped, but the heat applied likely helped. 

I've tried many PT oils. It's total BS. It will never penetrate (on its own) down a totally stuck shaft or thread, it just doesnt have those magical powers.

Heat always works because of expanding and contracting. Then I use old engine oil in a can as it doesnt evaporate instantly like most PT oils.
Logged

umop-ǝpisdn

  • Global Moderator
  • Forum Addict
  • *****
  • Online Online
  • Posts: 7394
Re: Can you identify this noise in my 1999 Sense?
« Reply #9 on: October 20, 2018, 12:48:57 AM »

Nicely done Pete.

Not sure if you know of them already or not, but there's quite a few online Hyo parts sites.

In Korea, you have:
koreanbikeparts.com
hyosungwholesale.com
hyosungsource.com

In the USA you have:
ragingparts.com
hyosong.biz

In Australia:
www.hyosungpartsonline.com.au
Logged
I used to be a sensitive, new age guy, but times have changed and now I am more of a caring, understanding, ninties type.

Pages: [1] 2