CVT cover WAY too hot (venting) By rosiemoto (Read 3,665 times)

[rosiemoto]

I've been going through belts like crazy lately and found out it could be the heat inside the CVT area. Touching my CVT cover after a ride was not possible.. too hot. I decided I'd drill some holes in the cover to vent it, after reading about some people's success doing that. I thought I'd share my version and experiences.

First I started with a bunch of holes on the side of the clutch area, and 3 holes in the back. That alone didn't help at all. I then took off the rubber intake cover/filter, and then I noticed a decent difference; I could hold my hand anywhere on the CVT for at least a couple seconds now! Intake area became only warm, and clutch area could be touched but only for a couple seconds. I felt it was still much too hot in there though; opening the cover and touching the variator, clutch bell, and belt nearly burnt my finger the instant I touched it.

Today I just got done drilling more holes in hopes to get more airflow. I created an intake for the clutch area, and a bigger hole for extra exhaust. My attempts of drilling the bigger holes aren't pretty..all I had was drill bits to work with, no fancy grinders or other tools. Anyway, I haven't taken a ride yet with the extra holes, but if it doesn't improve then I heard it could be a clutch bearing or belt slipping. If belt is slipping, why would that be? CVT temperature is the same on a brand new belt.

Here's some PICTURES... the pink thing underneath is just a dollar tree "kneeling pad"..works well for sitting "indian-style" out there working on the bike. This is about as far as I'll go drilling holes, unless maybe someone strongly believes there should be a hole here, and a hole there for best venting. I'll update when I go for my next ride, on how the heat is doing.

[cyborg]

I think if you wanna get more holy,,,you'd have to go to church

[jct842]

amen

[rosiemoto]

You guys are silly. Well it seems the extra holes did NOT help at all , so maybe I do have a problem in there that's generating too much heat. Anyone have ideas? Possibilities I'm thinking is: belt constantly slipping without me knowing, clutch bearing, or clutch slipping. I can't feel or hear any slipping though! Except for, I was beginning to hear a little bit of creaking as the clutch engaged during takeoff, but I think it might've stopped since the new belt.

This might be something: When reassembling the CVT, when I manually squeeze the clutch pulleys apart to give slack to the belt, the belt keeps freely sliding right back to the top of the clutch. Is this a sign that the belt is slipping on the clutch pulleys??

I've read that you should sand all the pulleys when putting on a new belt... I've been through 3 or 4 belts with these same pulleys in the past 7 months, and I cleaned the variator pulleys with soap+water, but never touched the clutch pulleys. Sounds like I should give it all a good scrub and a little sandpaper, huh? What do you all think could be going on?

[jct842]

I have seen the covers that had more holes than metal. That being said the heat of the engine which is aluminum is transferred thru the left side case right along to the end of the clutch cover. Just like a frying pan, you heat it with the small simmer flame and the outside edges get just about as hot as the center where the fire is.

Welding aluminum takes much higher heat than to weld steel because it transfers the heat so readily. Probably the only way to cool it would be more fins. It is not the belt and clutch making the heat, it is the engine and the holes should help.

[rosiemoto]

I saw some scooter racing pictures and their holes seem to be only at the under side. I don't have any there except the stock vent, which I took the metal piece out from inside. I was thinking also, maybe I need MORE air coming in from the front. Or just more holes everywhere I guess?

I drew a picture of what I'd do if I went crazy with more holes... do you think this would be an improvement, or more more more?

[cyborg]

Have you looked at the contra spring?,,,,maybe a wrap broke off

[rosiemoto]

Cyborg, yeah I've actually been wondering for the past couple weeks if the clutch is acting right. When I'm slowly accelerating, at about 10-15mph I can feel as if the clutch pulleys are shifting to a different gear, because I feel the pulling force going back and forth a few times, but the RPM stays the same. But especially with new belt, RPMs are too low and refuse to go above 5800 (& weak acceleration) until 35mph, then it starts returning to normal. It's like it won't downshift to rev higher. It also happened with my previous belt, but not "as bad."

Can what you said be checked without opening up the clutch? If so I can take pictures. I just don't yet have a wrench big enough for the clutch. I've been keeping my eye open at thrift stores.

[cyborg]

When you've been in there you haven't found a piece of wire have you?

[rosiemoto]

No... I don't remember seeing any wire or weird things in the CVT.

[cyborg]

The spring may have fatigued and has gotten weaker with time,,,probably one of the reasons you've been going thru belts also I would think

[rosiemoto]

Yeah my original belt lasted about 5 years, and was still going but I lost too much top speed so changed it. Belts wearing out quickly started around the time I got a new clutch; it was from eBay for $30, and arrived dirty, and was slipping/slow at takeoff until I cleaned out the bell and pads. I think you're onto something there!

What are the symptoms of a bad torque spring? Here's what I've got:
- Too-low RPMs/weak acceleration until 35mph+
- A creaking sound during takeoff
- Can feel the bike shifting gears around 15mph, as in I feel the acceleration change, but RPMs stay constant

[cyborg]

Don't take this wrong ok,,, buy quality parts,,, don't cheap out on parts,,, there is a difference,,, you know now what's wrong with the machine,,, I would change the clutch and contra spring,, end of story

[cyborg]

Also if there's a harbor freight near you lots of times they have great sale deals,,, you can get an electric impact and a rack of sockets very inexpensively ( like $40-50) all in

[rosiemoto]

I was there at Harbor Freight today and picked up a pipe wrench, but my gosh that clutch nut on my stock 6 year old clutch is STUCK. I was planning to open it up, clean it good, then put it in place of the one that's in now and see how it goes.

Question! I sprayed WD-40 on the clutch springs in it before (while assembled), and after a ride or 2 it went all over the clutch pads and inside of the bell. I cleaned it before, put it in, and it happened again... this was months ago... do you think the WD-40 would have dried up by now and won't be a problem now if I clean up the pads and bell once again?