Hillard Clutch Issue

Hey everyone,

Looking for some guidance on my Hillard flame clutch. I am having an issue where i have an excess amount of slippage. This weekend in one of my heat races I had a terrible start because the kart just wouldn’t go so I had changed shoes for the final. Immediately leaving the grid the engine revs to the moon then starts to move just absolutely torching the replacements.

Been running the same set up for a while now and have decent luck with it but this seems to happen not to often but often enough where I am scratching my head with what to do.

2 black 2 white 1 heavy weight in the outside hole towards the tip on each

Is the life expectancy of the drum the same as the shoes? Change one=change both?

Has anyone found manufacturing inconsistencies?

I’ve tried lighter springs but just get walked coming out of the corners/pulled down the straights. It just doesn’t work.

Any help would be awesome!

-Arann O.

New springs? Less chain lube? Less grease on the needle bearing?

It’s almost not worth it to completely rebuild one and replace the drum vs buying a new one.

Sounds like grease got inside the drum. Did you clean out the drum between rebuilds?

I clean the drum with sandpaper and wipe it out real good before putting it back together. The instructions that come with the clutches from Hillard say to clean with wd40 because they are powdered shoes.

In my eyes that doesn’t make a lick of sense but i follow what their recommendation is. Do you guys do the same? When I ran Yamaha I’d spray clutches out with brake cleaner when rebuilding them.

The I know the cost of a new one is cheap but it really doesn’t help my question as I have had this happen on two different kits.

I must be missing something…

Arann did this occur out of the blue or was there some maintenance activity that could have caused the issue? I would have to think if the springs weren’t changed somehow the friction surfaces became contaminated. What I’m not sure is whether you can save the shoes and drum or do they have to be replaced.

Rob,

It’s happened at least twice. One of the days I had to pack up because I didn’t have spare shoes. Each time I’ve replaced them, new springs go in and I lap the drum.

I’ve never replaced the needle bearing but it appears to be in good shape. I grease it moderately but clean my hands when putting on the drum.

What type of grease do people run? I just use some synthetic stuff I have in my garage. Does anyone run a sticky chain lube like a xeramic instead of conventional grease?

I only oil the chain once a day at the track

I’ve been told from the get go to use chain lube after each track session. I think that’s the conventional wisdom. But, it may vary from engine types.

“Moderately” may be too heavy. Centrifugal force can fling it into the rest of the assembly, so I go very, very conservative with Xeramic. I’d much rather under-grease the bearing than overdo it because that bearing is only there for idle. In my mind, that bearing is unimportant relative to getting grease inside the clutch.

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I’ve never followed the instructions on the WD-40 portion. Sand the shoes and drum, then brake clean both and reassemble. Put 1 drop of motor oil on the needle bearing and run it. I’ve run the same clutch for 4+ seasons without issue.

Other thing to mention is make sure you have the shoes in leading direction, not trailing.

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Not trying to highjack but my son’s Inferno Flame was fine last time we ran it which was a practice day at NCMP about 5 weeks ago. At that point it had 3 weekends on it. We have been working on the kart lately and axle rolling smooth. Loaded up the kart and brought it to my work to scale it and at some point noticed that axle was not rolling good at all. It felt like a slight brake drag or badly aligned chain drag but after inspecting I knew it had to be the clutch. Curious what was up, but too lazy to pull the engine I let him try to scuff his tires on our concrete lot for a bit. He simply went about 60 feet around the building started to smell something burning, could hardly accelerate so he hit the kill. Clutch had smoke out of it for minute. We let it cool off a bit, put it on the stand to find the axle rolling smooth again and the clutch engages on the stand normal. I am wonder what you guys think I am going to find when I pull it by this weekend. I need to swap our other new one on anyway due to needing to go up a tooth on the driver. I will report what I find when I pull it apart. I assume a sticking shoe was to blame, maybe from debris or corrosion.

Parking lot scrubbing is really hard on clutches, especially as you state 60’ and turn around. The whole time he was driving that clutch likely never locked up and was slipping and cooking itself. I’d just dress the shoes well and sand the drum, throw new springs at it and go for it.

Agree, and I thought about that since he basically when 15-20ft and turned while still on the gas. But the drag present on the stand was there before that and had came out of nowhere. And now it is gone. Again I will pull it apart and see.

Is it the original Flame drum? Is it solid all the way around or does it have some vent holes at the perpendicular bend in the drum?

Something to keep in mind and it’s a little tricky to explain fully but let me try. Not all drag on the stand matters.

  1. Could be a dry roller bearing in the clutch - drop of oil at the bolt head will work its way in and free up *does not effect kart’s speed on track once clutch is locked
  2. Chain drag - either dry or too tight, dry can slow you down and eat gears, tight will not slow you down on track
  3. axle bearing drag - likely dirt in bearings, in theory slows you down but it’s not enough to lose you a race unless it’s locked up
  4. inner clutch shield rubbing drum - just how the clutch works into itself, noisey and draggy * does not effect speed when the clutch is locked up on track

interesting thread for me, cuz i’ve never, ever had an issue with the flames. i’ve sprayed wd-40 straight into them, too, with no issue. i’ve changed shoes, no issues, just cuz. i do trade out the springs though, every now and then. if you compare a half season old spring to a new one, you can usually see the used spring appears a bit more expanded. i don’t think it really matters much, though.

main thing i hate about the flames is dropping the key, lol.