Going through belts like crazy - variator? fan? By rosiemoto (Read 892 times)

[rosiemoto]

I'm trying to figure out why I'm going through belts and CVT is getting so hot. I've gone through 3 or 4 belts this year. I was just told to check my variator fan as a cause of the excessive heat in my CVT. I was told the variator fan could be put on backwards and cause heat.. I don't see how that's even possible to put on backwards?? BUT I do have a smaller variator fan about 107mm that comes from my local shop I bought it from. It does NOT seem to be the fan that's usually put on stock scooters! Its fins stick out past the pulley.
(107mm fan) vs (115mm fan)  <-- Pictures

I also have a bigger variator in (Koso 115mm), so they're mismatched in size but seem to be working great performance-wise. I figure mismatch isn't a problem because scooters come with 107mm variators and 115mm fans and are mismatched stock anyway! Mine's just mismatched "backwards." I was wondering though, the Koso variator does not allow the belt to ride to the top of the clutch pulley at idle I guess because of the ramp shape.. so it's almost but not quite like taking off in 2nd gear. I was wondering if that was possibly wearing the belts down too? The main problem is they get THIN quick and they leave tons of belt dust.

I have bought 2 different 115mm fans online and both seem to be cheaply made with weird ramp angles and the 2 holes for using a pulley holding tool are much smaller. Last time I tried the 115mm fan it didn't seem to affect the heat, or at least in how hot the cover got... so I'm not sure what to think... does the bigger fan help at all with cooling? Or possibly do I need to go back to stock variator?

Drilling holes in CVT cover seems to have helped a lot, but I'm not sure if it's enough and afraid to buy another new belt if it's just gonna fry it to death too.

[rosiemoto]

Just did some more research on gas, octane, etc, and I'm seriously wondering could it be that I'm using too low octane gas and overheating the engine, which is transferring the heat through to the CVT, since they're basically "neighbors"!?

The past 2 weeks I've switched to ethanol-free 87 and have noticed my CVT cover has gotten burning hot again lately, yet in the reverse order - clutch side is now touchable, and the middle and intake (front) side is way too hot to touch. Very strange because clutch has usually been the hottest side. I am wondering if it's simply the gas is pre-detonating slightly or something.. and I say slightly because I don't hear anything obvious. I was told from the shop I bought my bike from, to ALWAYS use premium (93) gas. I never asked why exactly, but I'm thinking there might be a good reason and this might be one of them. My emissions tag on the side says 87 or higher, but at the gas tank under the seat, it's got a sticker that says 90 or higher. Confusing.

I don't hear any loud sounds, but I DO hear a quiet "engine rattle" (different from bike vibration) sound while riding slow or on side streets, and a high pitched rapid dinging sound at idle. The dinging I notice right away when the CVT cover is off and it comes from the variator area, or more like "behind" the variator...and what's there? ENGINE! (at least I think!) I don't believe it's the variator or rollers because I've swapped all that out many times and it always persisted. So I think that sound could be engine pinging. I already adjusted my valves to .004" each a couple months ago.

Taking a ride at nighttime doesn't seem to help the heat at all. I also just did an oil+gear oil change and no help in heat from that either. I'm going to give it some good 93 gas for a few tanks and see how it goes, and hopefully these heat problems are as simple as the gas I've been using!

[jct842]

Pinging usually happens when the engine is under load. Is possible the cam chain is loose. Not totally unusual for the tensioner to go south. A rattle is more like a chain loose.

[rosiemoto]

That makes sense. That rattle I was talking about does sound a lot like when you pedal a mountain bicycle and you hear the chain going around. Like, certain gears would be quiet, and others have a slight rattle... <- that.

Um, other than that I get a sound like marbles clacking really fast at 7k RPM. I also lose power around that RPM.. it's like I must gear the bike to stay under 7k at all times.

Well I'm on my 2nd tank of 93 gas, and so far the CVT is still as hot as ever. Today I tried returning the A/F screw on the carb back to how it was stock (4+ turns out), thinking maybe I've set it too lean from when I adjusted it before. It stilllll seems to be the same temperature. 

I mean, I'm assuming my belts have been wearing out too fast because of the heat, OR is it just real bad luck and I've gotten 4 bad quality belts in a row? Two of those say Gates brand on them.

[cyborg]

The belt and case of my Vespa et4 would get ungodly hot ,,, untouchable