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Post by byufanatic on Jul 17, 2008 22:26:24 GMT -5
Question for those of you who have replaced drive belts before:
Should it be possible to put the belt on the rear pulley and then BARELY squeeze the belt over the front roller WITHOUT pulling the clutch pulley open?
If the answer is NO, then perhaps that might be a factor in making my top end speed disappear (just speculating).
Rob
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Post by "Big Guy" on Jul 17, 2008 23:15:06 GMT -5
The answer is yes, you squeeze the clutch plates and lower the belt to the lowest position on the clutch and then then remove the belt from the variator... easy and quick.
-Rich
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Post by byufanatic on Jul 18, 2008 0:52:58 GMT -5
The answer is yes, you squeeze the clutch plates and lower the belt to the lowest position on the clutch and then then remove the belt from the variator... easy and quick. -Rich Then you mean "no" right? *smile* I just asked if it's possible to slide the belt on to the variator shaft WITHOUT squeezing the clutch plates. This might be why my belt is rubbing against the benix. If I can (barely) wiggle it on to the variator shaft by hand without squeezing the plates then perhaps the engine, with all its torque, is causing the belt to ride too high on the variator pulley - in essence, my replacement belt might be at LEAST a few millimeters too long. Tomorrow I'll have to pull the belt and look at the part number on it. According to the Roketa website, their "official" part is: CVT BELT 669/18/30. I'm guessing the 18 is how wide it is (and that it should be no less than 17 mm). The 669 must be the length (in mm). And the 30 must be the angle? Rob |
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Post by Enviromoto on Jul 18, 2008 14:02:23 GMT -5
yep you got it rob.
Are you sure your getting enough fuel to carb?
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Post by byufanatic on Jul 18, 2008 14:22:47 GMT -5
The fuel filter is always full of fuel and the spark plug is reading normal.
I'm wondering if there's something up with the CVT which is causing too much resistance - and thus causing the hesitation and loss of top speed.
The CVT cover is getting HOT after only a couple miles of riding. I've pulled the cover and checked things out multiple times but can't seem to see anything wrong.
Maybe I'll put it together without the bendix in it and see if it gets hot without it.
Rob
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Post by byufanatic on Jul 18, 2008 23:11:08 GMT -5
gang -
you'll never believe it. I found the cause for loss of top speed:
The outside variator plate was flattened a bit where it slides on to the shaft. I am camping with my son right now so I will post pictures when I get home.
My top speed is now around 35ish.
However... the CVT cover is still hot to the touch. I will post a more detailed update when I get home.
Rob
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Post by Enviromoto on Jul 19, 2008 9:30:02 GMT -5
The CVT cover will get hot.
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Post by imagesinthewind on Jul 19, 2008 11:06:16 GMT -5
I'm happy for you!!! Whew! Good for you! Now you know everything there is to know about your scooter! Happy riding! I'm jealous! SO, these do go faster. Maybe my variator has the same thing?  Have fun camping! |
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Post by byufanatic on Jul 19, 2008 15:46:25 GMT -5
Jeremy - You sure it should be getting hot after a couple of miles? I took it for a spin - couple miles - hit 35mph+ on a few stretches. Stopped, touched the CVT cover and was able to hold my fingers to it for about a second ("one thousand one"). If I would have held my fingers against it any longer I would have got burned. I thought I remember reading others' posts about their CVT covers getting warm, but not HOT.... Ginny - I'm seeing the light at the end of the tunnel (either that, or it's an oncoming train). I'm not ready to pronounce the patient as "healed", but it is making progress. Maybe I'll take it out for an extended spin later today. Although the hot CVT cover is making me nervous. Ok... the variator story that I promised earlier: I pulled my variator apart again and was comparing it to the one on the other engine I had. Then it hit me like a bolt of lightning. The two plates are shaped slightly different! I had taken a picture of them side by side before I left to go camping but accidentally deleted it. Sorry about that. But, if you look at the picture below, you'll see where I marked with arrows how the variator slopes from the outside then at the arrows it slopes down to where it connects to the shaft. It's not supposed to do that. It's supposed to continue sloping up all the way to the shaft. I'm guessing that what happened is when I put the variator plate back on after replacing the brake and put the three-prong retainer/kick-start-gear on backwards and tightened it down I flattened the "cone shape" of the variator plate. This would cause the belt to ride up too high and contact the bendix. It would also cause the belt to deal with excess pressure/friction when idling - thus explaining why I had no power when trying to go from a stop. So, I put the other variator plate on and PRESTO! I got my top speed back. It is still kinda slow accelerating at low speeds, but pulls strongly (for a 50cc) up to top speed from the mid-speed range. Here's the bent variator plate: (the arrows mark where the slope stops going upwards and starts downwards as it gets close to where it meets the shaft)  Rob |
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Post by indy50 on Jul 19, 2008 16:28:10 GMT -5
Rob, don't feel bad about your smashing the variator. I once did a similar brain fart. after rebuilding a engine, I installed the variator and impacted the bejeezus out of the nut. I hung the engine thinking I had a fresh rebuild and the thing would barley start and when it did it seemed like there was lots of resistance somewhere. After three days of tearing the thing down and finding nothing wrong with the top end. I discovered that I had way overtightened my variator and it was crammed against the case. Duh! Sh*t happens. Just cause it says Guru Dawg under my moniker, doesnt mean Im a genuis, just means I been here awhile and post alot ;D
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Post by imagesinthewind on Jul 19, 2008 16:28:21 GMT -5
Cool for you!!!
Let us know about the extended ride, I'd love to know what the
real top speed is after a good ride.
Unfortunately for me, your variator problem probably isn't my problem so
after it's finally running I'll have to find out why mine is topped at 25mph.
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Post by byufanatic on Jul 19, 2008 19:12:14 GMT -5
Estimated new top speed is approx 35mph. Could possibly be slightly faster as I ran out of road. I'll need to find a different place to test my speed or borrow someone's GPS unit.
The CVT cover is still hot to the touch - but I was able to touch it for two seconds rather than one. Jeremy says this is normal. I'll take his word for it since it's bolted onto the engine casing and the engine definitely gets hot. But I'd like to hear back from everyone else.
So here's what I need from everyone:
How hot does your CVT case get after a ride? Just put your fingers on it and count (one thousand one, one thousand two, ...) and see how high you get before it's too hot to keep touching.
PS - I just wanted to say thanks to all of you who have been helping me out in this thread. I REALLY appreciate it BIG TIME. Bones for all of you (as fast as this board will let me dole them out).
Rob
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Post by imagesinthewind on Jul 20, 2008 12:08:52 GMT -5
So Rob, you out riding?
Have fun!
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Post by byufanatic on Jul 20, 2008 17:42:02 GMT -5
Took it out for a nice spin last night. Picked up my daughter from her friend's house and stopped at the gym to workout. It ran well. But I'll say this - it has no guts. *grin*
With both my daughter and I on the scoot the only time we got it above 30mph is on a downhill or with a very long (and flat) road.
When I'm riding solo it's not bad. But with a passenger we "puttered" around most of the time.
Rob
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Post by imagesinthewind on Jul 20, 2008 18:09:13 GMT -5
Well, at least it's running faster and better for you.
Will you try another carb adjustment? Might that
be what is taking away it's guts?
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Post by isawhim on Jul 20, 2008 19:08:50 GMT -5
That would have changed the whole range... Since the bend would also have moved the whole pulley inward... it would have pinched harder, attempting to push the belt above the outter rim. (If the belt is 20mm wide, and you indented the pulley 3mm, it would be 17mm wide at the top now, and that would attempt to push it higher, since it would be trying to compress the 20mm into 17mm, while the belt rides the CVT case, causing friction.)
You may get gains from a lighter set of rollers. That will retard the CVT raising, and give you more lower power, and possibly higher speed, since that 35MPH will have more power to the spin. I am guessing that it is rising way too fast, thus, it gets to 35MPH, without any power, since it jumped right up into high-gear, too fast.
A longer belt or thinner belt would give you "Chatter", as it slips between the pulleys. It would also have severely altered your power and response. The additional "Pinch" at the bottom, would have made your starting real difficult. Again, because that starts it in a higher gear, since it did not drop down all the way.
How did you do that again? Did you over-tighten it while the belt was on, near the center? The rollers must have been out all the way... That is just an odd bend...
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Post by byufanatic on Jul 20, 2008 23:10:53 GMT -5
Well, at least it's running faster and better for you. Will you try another carb adjustment? Might that be what is taking away it's guts? Nah. At the moment, no more carb adjustments (unless I opt for a bigger jet). My kids will also be using this scoot to run around on when they get their licenses (in a year for one, two years for another). So the last thing I want to do is make it go fast (kids and speed don't mix well sometimes). This is just a tiny little 50cc. So "gutless" is something to be expected. It was not built for a full-size rider and passenger (despite the big enough seat). Rob |
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Post by byufanatic on Jul 20, 2008 23:13:18 GMT -5
That would have changed the whole range... Since the bend would also have moved the whole pulley inward... it would have pinched harder, attempting to push the belt above the outter rim. (If the belt is 20mm wide, and you indented the pulley 3mm, it would be 17mm wide at the top now, and that would attempt to push it higher, since it would be trying to compress the 20mm into 17mm, while the belt rides the CVT case, causing friction.) You may get gains from a lighter set of rollers. That will retard the CVT raising, and give you more lower power, and possibly higher speed, since that 35MPH will have more power to the spin. I am guessing that it is rising way too fast, thus, it gets to 35MPH, without any power, since it jumped right up into high-gear, too fast. A longer belt or thinner belt would give you "Chatter", as it slips between the pulleys. It would also have severely altered your power and response. The additional "Pinch" at the bottom, would have made your starting real difficult. Again, because that starts it in a higher gear, since it did not drop down all the way. How did you do that again? Did you over-tighten it while the belt was on, near the center? The rollers must have been out all the way... That is just an odd bend... Yep, basically that's what it was doing - the flattened plate was pushing the belt up too high and was pinching it too hard in idle. But, fortunately that problem is now fixed. I did it by putting the three-prong washer/fan-holder-thingy on backwards. Sorry, don't know the name for that thing. Directly under the nut is a three-prong metal washer-type thing and I had it on backwards. I tightened everything down with my impact wrench after changing the belt and if you've got the washer on backwards, it can flatten the variator plate. Rob |
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Post by tortoise on Jul 22, 2008 11:39:21 GMT -5
is your CVT cover hot to the touch (can't touch it for more than a second) after a ride There are numerous variables, but this 139QMB reading was taken after ascending an inclined section of road . . around 1700' elevation, 90°F ambient air temp, and 185# driver weight (in full riding attire).  |
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fastgast
Big Dawg
Go fast, turn left
Posts: 19
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Post by fastgast on Jul 22, 2008 12:23:25 GMT -5
I'm running a znen 50cc and after 7 miles it is pretty warm to the touch but not hot. Thanks to youall for the tips and tricks really helped me get to 35MPH  |
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Post by mixxxxmaster on Jul 22, 2008 21:23:36 GMT -5
WOW.............. Rob I am kinda of lost this thread, was a bit long! For starters I don't think that is TDC you need to line up the T not the F Take a picture of the T lined up with the tab and another shot of the cam and we can tell from there!
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Post by miles4less on Jul 22, 2008 23:31:55 GMT -5
The CVT cover is still hot to the touch - but I was able to touch it for two seconds rather than one. Jeremy says this is normal. I'll take his word for it since it's bolted onto the engine casing and the engine definitely gets hot. But I'd like to hear back from everyone else. So here's what I need from everyone: How hot does your CVT case get after a ride? Just put your fingers on it and count (one thousand one, one thousand two, ...) and see how high you get before it's too hot to keep touching. Rob I've been trying to fix my hot running CVT cover for a couple weeks now. Air scoop on the air inlet, removed some of the pieces that seem to stop any airflow inside the cover and drilled a few holes in areas to increase airflow. Nothing seems to make a difference. Still only able to touch it for a couple seconds. People say heat kills belts but I've got the stock belt with almost 700 miles (1100 km) and it's holding strong. I've got a spare ready but I'm curious on how far this one holds up. |
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Post by byufanatic on Jul 23, 2008 0:42:10 GMT -5
The CVT cover is still hot to the touch - but I was able to touch it for two seconds rather than one. Jeremy says this is normal. I'll take his word for it since it's bolted onto the engine casing and the engine definitely gets hot. But I'd like to hear back from everyone else. So here's what I need from everyone: How hot does your CVT case get after a ride? Just put your fingers on it and count (one thousand one, one thousand two, ...) and see how high you get before it's too hot to keep touching. Rob I've been trying to fix my hot running CVT cover for a couple weeks now. Air scoop on the air inlet, removed some of the pieces that seem to stop any airflow inside the cover and drilled a few holes in areas to increase airflow. Nothing seems to make a difference. Still only able to touch it for a couple seconds. People say heat kills belts but I've got the stock belt with almost 700 miles (1100 km) and it's holding strong. I've got a spare ready but I'm curious on how far this one holds up. Thanks for that info! I was thinking about drilling holes and removing some air flow obstructions inside the cover but if they haven't made any difference in your case, they likely won't make a difference in mine either. I've heard conflicting reports too - some people say the CVT cover is supposed to get hot and others say theirs is "just warm". I've asked people to do the "fingers against the cover" test for me and so far I haven't gotten any responses except from Tortoise (who used a temp sensor - which is pretty cool, but doesn't help much since I don't have one to compare with *grin*). One question - has yours always been hot, or just happened within the past couple of weeks? Rob |
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Post by mixxxxmaster on Jul 23, 2008 0:50:19 GMT -5
THATS NOT TDC
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Post by mixxxxmaster on Jul 23, 2008 0:53:02 GMT -5
whoops wrong post
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Post by miles4less on Jul 23, 2008 9:18:07 GMT -5
I've been trying to fix my hot running CVT cover for a couple weeks now. Air scoop on the air inlet, removed some of the pieces that seem to stop any airflow inside the cover and drilled a few holes in areas to increase airflow. Nothing seems to make a difference. Still only able to touch it for a couple seconds. People say heat kills belts but I've got the stock belt with almost 700 miles (1100 km) and it's holding strong. I've got a spare ready but I'm curious on how far this one holds up. One question - has yours always been hot, or just happened within the past couple of weeks? Rob It has ran hot since I've had the scooter, which has been a little over a month. It has just been on my mind a little more the last couple weeks since the temps around here have been close to 90. I'd like to add that most of my trips are 5+ miles and mostly wot. That is about all it takes to get a hot cvt cover for me. It doesn't seem to get any worse on my 15 mile trip to work. |
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Post by byufanatic on Jul 23, 2008 10:06:30 GMT -5
Looks like you're riding your scoot a lot more than I am at the moment, so if this kind of heat is gonna kill the belt, yours will probably die first. *grin*
Let's just hope you and I are worried about nothing. But, keep me posted!
Rob
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Post by indy50 on Jul 23, 2008 10:25:03 GMT -5
cvt covers on 50's offer poor ventilation. just keep a close eye on your belt. My 82 used to get waaaay hot. I modded the cvt cover by cutting vent slits and opened up the internal passages to prevent premature belt wear. Carry a spare belt and an 8mm deep well so you can change belt roadside. Also remove plastic filter thing at the front of cover.
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Post by byufanatic on Jul 23, 2008 16:35:32 GMT -5
cvt covers on 50's offer poor ventilation. just keep a close eye on your belt. My 82 used to get waaaay hot. I modded the cvt cover by cutting vent slits and opened up the internal passages to prevent premature belt wear. Carry a spare belt and an 8mm deep well so you can change belt roadside. Also remove plastic filter thing at the front of cover. Mine if I see a pic of where you cut your slits? Did you basically punch or grind out all the internal "squigglies" that the air is forced to flow around? I'm thinking of epoxying on some extra plastic to make the cooling fins bigger. Good idea to carry around a spare belt. Question though - how do you get the belt ON without an impact wrench? I can compress the rear spring by hand if it's off the scoot, but on the scoot I can't seem to squeeze it enough to slip the belt over the rear pulley. Rob |
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Post by byufanatic on Jul 26, 2008 23:18:14 GMT -5
Yo Indy -
While I'm waiting for your response (see post directly above this one) I have a question for you and others out there who may know:
My acceleration from a stop is very unimpressive. Especially if on an incline or with a passenger. Hill climbing can be equally unimpressive. I believe my rollers are 6 grams (weighed them once, but forgot). I want to go with lighter rollers to avoid getting cagers behind me upset at me.
I weigh around 193 lbs. About 1/4 to 1/3 of the time I anticipate I will be having passengers (one of my kids). They're between 50 to 100 lbs.
Would 5.5 gram rollers do the trick or should I try for 5 gram rollers? I'm willing to give up a LITTLE bit of top speed (still want to stay above 30mph) but need to have better acceleration and hill climbing.
Just to give you an idea - On one hill (not a big one, but it is a long one) my speed dropped down to just under 20mph. Not very fun/safe with traffic whizzing by me.
Rob
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