We are new to karting, and this is our first time cleaning the clutch after around 3 hours of use. When we took it apart, we thought it looked pretty bad. We bought this engine used (3 hours of use) and noticed that it seems to be missing 2 washer-like spacers. Does this clutch look bad, and should I be worried about installing another one and facing the same issue again? it seems like number 2 and 6 in the diagram
Thanks!
Not the worst I’ve seen, especially during the initial break in. Check the drum for signs of galling or overheating. Sand with 600 grit, spray a little WD-40 on a rag and wipe the inside of the drum. Take a wire brush to the shoes and that’s all the amount maintenance needed other than a very small amount of grease on the needle bearing.
Source those two missing washers and put it all back together in proper order. I’ve seen #2 missing on karts I’ve helped work on and not have an issue but #6 can allow the grease trap to contact the drum and make a ringing noise because the drum has some inherent wobble by design at idle. Once the shoes engage fully it’s not present.
We don’t run 2 or 6 ever.
Replace or regroove those shoes. All black springs and no weights slip too high, imo.
Help us understand what your seeing. If OP goes to all black springs wouldn’t that have more slip than say all white or a mix of black and white? Also, what do you do to regroove the shoes?
All black will slip more the the black/white combo. The pic looks like all black to me. I could be wrong on that because the whites can end up looking black.
Dremel or die grinder cutoff wheel cleans em out pretty good. A file does a good but slower job as well.
In the latest update, I noticed that the kart’s clutch was emitting smoke almost immediately after starting the engine on the ground. I was testing it on the street without going very fast. It appeared to accelerate faster, but when I attempted a full lock turn, I significantly reduced my speed and executed the turn. During this maneuver, I had to almost fully depress the accelerator for the kart to move at all.Is this normal? Additionally, I had adjusted the idle speed on the carburetor and cleaned the clutch—both of which I did for the first time. Unfortunately, I don’t possess a mychron, so I was unable to monitor the RPM while making the idle adjustments.
Been using the flame for years now and definitely haven’t seen my groves that covered after races of use. Are you over applying chain grease? Don’t need much for these. Usually take the clutch off and clean after each race. Two black two white no springs is what I run
i clean out the grooves after every race, so they don’t ever get that filled up. i use a small screwdriver to clean out the grooves. i use your same spring set up, no weights, and i really don’t have any issues on track.
Yes, racing clutches do not tolerate the repeated slipping that’s common while driving on the street. Usually they slip once at the start of a session entering the track and that’s it until the next session.
If you clean with WD-40 that could be burning off or a build up of chain lube on the outside.
Remember these clutches are spring loaded to engage as a specific RPM (depending on springs) so lower than that RPM it will slip. However, with a high load like accelerating from a stop or out of a tight turn it is going to slip as the motor builds RPM and the kart has less moving resistance. You might think about it like a bicycle. If you try to start moving on a bike and you are facing downhill its relatively easy, however, if you do that going up a hill it requires much more effort to get to the same speed. Try to turn your steering wheel and push your kart its hard to do, but pushing it in a straight line its much easier.
How often do people clean their Flame clutch with WD-40?
Fixed typo: flame instead of flange.
Several items in response to your post:
Yes those shoes look like they need some TLC. Simply rub down the drum ID with sandpaper as others have noted, then use a wire brush or sandpaper to scuff the glaze on the shoes. Glazed shoes will slip more. Then use a flat tip screw driver, file, or dremel to clean the grooves. This gives the wear material a place to collect and helps reduce galling of the shoe face and drum ID. Wipe it all down with a light coating of WD 40. We service our clutch after every race weekend, it’s minor but keep the maintenance easy. If you let it go until you notice a performance issue, then it’s way more effort to clean up.
As for the engagement RPM, you will hear lots of opinions. Typically you will see a recommended target an engagement of 3000-3400 for the 206 class. Truth is, at most tracks that engagement should be below you lowest corner RPM if at all possible. The only time that clutch should disengage or slip is on the start or in very heavy braking and very slow corners. Some people like no weights and some prefer the weights, but you simple mix the springs in pairs to get the target rpm engagement shown on the chart above.
We replace our springs after 2 race weekends or 1 big regional race weekend. They get soft from heat over time and IMO can negatively affect starts, so we replace them.
And the washers, sometimes we actually use 3 of them. 1 at the bearing and 2 at the grease shield. We do this because the stupid grease shields have a tendency to rip the keyway tab and the slip on the shaft and make a score line. 2 washers helps reduce that for us.
