low end bog part II (videos)

[oldyeller]

This is continued from my low end bog after new pipe post...Ok so I got my light wieght clutch from Hetricks and installed it today to try and help it get off the line better,..I am running the red torsion spring and the 3 small red engagement springs in the rear clutch and 5 gram rollers in the variator...Engine is stock 90 eton with a APex pipe and boyeseen reeds and uni filter...
The low end is better but it seems to stay kind of flat and seems to upshift quicker than before or is it possible the belt was slipping before?...Here is a before and after video

http://i45.photobucket.com/albums/f84/frdnut/th_MVI_5193.jpg (http://s45.photobucket.com/albums/f84/frdnut/?action=view&current=MVI_5193.flv)
http://i45.photobucket.com/albums/f84/frdnut/th_MVI_5234.jpg (http://s45.photobucket.com/albums/f84/frdnut/?action=view&current=MVI_5234.flv)

[dblacks]

do you have a spacer in the front variator to make sure the belt is as low as possible in it so that it is in low gear

[oldyeller]

No I don't..Here are some pics showing how the belt rides in the rear and you can see how high it comes up on the front variator..Seems like a lot of wasted travel that isn't being used..

http://i45.photobucket.com/albums/f84/frdnut/IMG_5221.jpg
http://i45.photobucket.com/albums/f84/frdnut/IMG_5232.jpg

[Reimer Racing]

For one thing your belt is to short. If your running a Bando belt get the 788 style from a Polaris 90. Or order a Malossi 6112741 the belts are longer. The problem with the belt you have is it is to short. So the bike is already staring out in 2nd gear. Longer belt will let the belt ride higher up on the clutch.

[dblacks]

Originally posted by Reimer Racing
For one thing your belt is to short. If your running a Bando belt get the 788 style from a Polaris 90. Or order a Malossi 6112741 the belts are longer. The problem with the belt you have is it is to short. So the bike is already staring out in 2nd gear. Longer belt with let the belt ride highr up on the clutch.

agreed

[raidernut]

exactly your problem, good job in posting the clutch pics, easy to diagnose

[vindell]

Hello all, Having the same issue, had motor mod's done, pipe,clutch kit. and our 70 travels 5-10 feet then hit'shard.
work was done by Corey at kool kidz. Had a suggestion from a member to switch to a 788 belt. purchased one and took to Corey when mods were done. He gave me the 70 back, however, left the stock belt on, he expressed this was the wrong belt?
Was excited to get quad on truck, didn't ask why? want more power off the line, gonna install 788 belt when I get home, also must I install all the rollers, or can I leave some out to see if I have a roller issue?

[etondaddy]

Originally posted by vindell
Hello all, Having the same issue, had motor mod's done, pipe,clutch kit. and our 70 travels 5-10 feet then hit'shard.
work was done by Corey at kool kidz. Had a suggestion from a member to switch to a 788 belt. purchased one and took to Corey when mods were done. He gave me the 70 back, however, left the stock belt on, he expressed this was the wrong belt?
Was excited to get quad on truck, didn't ask why? want more power off the line, gonna install 788 belt when I get home, also must I install all the rollers, or can I leave some out to see if I have a roller issue?
Leave the rollers in.....do one thing at a time. If you do more than one thing you loose track of what fixed it and what didn't. :huh



Mike Kozura

[Reimer Racing]

It would be easier to call Corey and ask why he perfers the 780 belt to 788 belt. I think if you were to take a poll on here most people on here run a 788 belt when they use stock clutchs.

[oldyeller]

Ok I got the new 788 belt..It looks like it is up in the rear clutch a little more but not as much as I had hoped(old belt on the left and new on the right)..It is also a little over 1mm wider than the old 780 belt..I'm not sure it this is just due to wear on the old belt or not?..Anyway It looks like it is sitting up in the front variator a little more than the old belt as well so I'm not sure I have gained any more low end gearing by swapping the belt...Is there a way to open up the front variator to let the belt sit lower in the front so then it could sit higher in the rear clutch?.......I have also noticed now with the light wieght rear clutch that the clutches are starting to open/shift a little before the clutch engages so I am losing a little gearing there as well.(see video below).Do I need lighter roller,stiffer torsion spring or lighter engagement springs in the rear clutch to stop this?

http://i45.photobucket.com/albums/f84/frdnut/belts.jpg
http://i45.photobucket.com/albums/f84/frdnut/th_MVI_5240.jpg (http://s45.photobucket.com/albums/f84/frdnut/?action=view&current=MVI_5240.flv)

[neveready]

The 788 is a great belt, but..... it requires some rear pulley mods and some variator tricks to make it perform properly. The 787-16-30 is a more user friendly belt for most users.

[Reimer Racing]

Post a pic of the front var. that might be your whole problem. Some of the Eton Varieters came with a soild outer ring those varieters never open up enough to drop the belt down. As for the diving down before the bike moves that is a shoe spring problem. Try putting on a stock clutch shoe setup. then see if it dives down.

[oldyeller]

Originally posted by Reimer Racing
Post a pic of the front var. that might be your whole problem. Some of the Eton Varieters came with a soild outer ring those varieters never open up enough to drop the belt down. As for the diving down before the bike moves that is a shoe spring problem. Try putting on a stock clutch shoe setup. then see if it dives down. Not sure what you mean by "outer ring"? Here is a pic of the variator parts..

http://i45.photobucket.com/albums/f84/frdnut/IMG_0736.jpg

[Reimer Racing]

Ok here is where the fun begins. The outer ring is where the rollers roll out to at there farththest point. Most var. have cut outs so the rollers can roll father out thus giving you more top speed. In your case it the other end we need to work to get the bottom end.

Do you have access to a lathe? you are going to need to turn down both faces. That way the belt will sit deeper into the Var. What I am trying to say is that you need to open up the bottom so the belt sits down in.

If you want call me and I will explain it better.

[oldyeller]

Ok I think I know what you are talking about now.(does the pics look right?).I do not have access to a lathe or machine shop so I would have to pay someone...Is there a an aftermarket or different variator that comes with these cutouts already?

http://i45.photobucket.com/albums/f84/frdnut/img_0735fgh.jpg

[dblacks]

Turning down the fixed halve will work but you may need to still add a spacer to get the belt all the way down it, may dont have access to a lathe so they just use spacers.

I would just add a washer in as a spacer to seperate the 2 halves a little more and then you will be able to get the belt all the way down so it will start off in low gear.

Put the variator on the crank, put the hub in, add a washer that will fit over the crank but isnt taller then the hub diametier and then put the fixed halve back on with the star washer.

If you dont have a washer that will do it take the hub down to the hardware store to get one that matches the inside and outside diametier.

Once you get that solved I would then try to get 6 rollers that match the weight of the 3 that are in there, 3 is okay for testing or when in a pinch but that is a lot of stress on 3 rollers when you kid gets riding hard, it is desinged for 6 for that reason.

[oldyeller]

dblacks if I do that will I still have room to put the star washer back on afterwards?..Seems to me like adding a shim would move the whole fixed half over leaving less room on the outer edge of the shaft to get the star washer back on (it is already pretty tight)

[dblacks]

It doenst take much to shim it out and you only need a little bit of teeth showing to catch the kick start gear

You may need to look at the shim on the inside as well as there should be one still on the crank, you may need to take a bit off from that to move the whole assembly in towards the case just a touch.

[oldyeller]

There doesn't appear to be anything removeable on the inner side to free up any room..

http://i45.photobucket.com/albums/f84/frdnut/IMG_0734.jpg
http://i45.photobucket.com/albums/f84/frdnut/IMG_0733.jpg

[oldyeller]

So I would try to add a washer here?..In between the inner sleeve and the fixed outer half?

http://i45.photobucket.com/albums/f84/frdnut/ghj.jpg

[Reimer Racing]

You are getting the idea. If you can get rid of the ele. starter that would be good. You will need to add a 3mm shim in place of the starter ring. But add just a 2mm spacer that way it will give you a little on the star side. kinda like robbing peter to help paul. I am leaving for a race so i will check back sunday nite. If you need to call feel free.

[oldyeller]

I really don't want to get rid of the electric start..Is there any other way to get full range out of the trans?..We don't race just looking to make a stout little trail machine and the electric start works so well..

[Bill Lemans]

If you don't wish to remove the starter ring, you can still do the shims safely by adding the mentioned spacer, I think mine was .02-.03 thick, then you can grind a little off the star and/or the inside of the kickstart ring. Very small amounts. To be honest , I don't think your shim would be thick enough to worry about the star. When I did mine, it was only the kickstart ring that was affected cause it sits at the end.
I'm getting ready to do the vario mod on the cnc, to allow further roller travel.It could be done by hand as well. I may have an extra old eton vario I can mod at the same time and send it your way for trial.Doesn't take much longer once it's programmmed. If you like it, send me yours and i can do it as well. I'm not sure how much you'll notice it on the trails, but I do know that my 11 yr. old wished his had more top end for trails before he was riding a bigger quad.

[Bill Lemans]

Just looked , only have the fixed half. If you have any epoxy putty, try this ;

Remove your fixed half and belt. Take a marker of some kind and color the pin, where the belt rides, all the way around. Reinstall your fixed half but not all the way. Push some putty in there and snug up the bolt until it starts squishing the putty to about 1/16 "or whatever looks good by eye so the fixed half isn't squishing the belt, then let it set up.

After it sets up, reinstall belt and and reassemble the vario. Be careful to keep slack in the belt, so you can snug up vario nut without any belt tension on the assembly.Typically when you reinstall the variator the fixed half cocks slightly until it's seated on the shim due to belt interference. Although the epoxy's are strong, they will crumble,so it's best to have it sitting flat before you tighten it. Then let the belt sit normal and spin it . Check to see if the marker wears off.If it does, your belt is all the way down ,all you have to do is sand or file the washer off a bit at a time until your fixed half just makes contact with theside of the belt.
Essentially you have made a fit washer that you can now copy out of a steel washer.
If your washer thickness is close to a standard size you can purchase ,you can file and stone the washer to the correct thickness.Then you can grind off the od and id by hand with dremel or whatever you have.I found one that fit the id and put it on piece of threaded rod between washers and nuts and put it in my drill press(or cordless) to effectively make a mini lathe. just spin it and apply your hand grinder, file, or whatever you have.

The whole process might take 1/2-1 hour or so depending on how close of a washer you can find.

Another thought is to find an old variator pin and use a thin cutoff wheel to slice a piece off, then grind it down to correct thickness. I did this the second or third time......worked well.

It seems like alot to do but it's really not. Of course, I like to play around with stuff,and this is more of a hobby that we race, so it's kinda fun for me:D

[Logan #34's Dad]

Come-on! Just get on a couple scooter sites and buy a pack of shims made just for this purpose. They come in all different thicknesses to get it just right. Your crank appears to be a 90cc size spline (eton) so it may be a little harder to find the shims.
Try: www.scootercraft.com
I think this will work - you'll have to measure the thickness of the output shaft.
http://www.scootercraft.com/product_info.php?info=p18221_Stage6-Variocontrol-Adjustment-Washers---14-8mm-x-20mm.html
Good luck.

[Team-Ty]

Well you can't just shim it if you want to have the full travel of the belt. If you look at the back of the front variator the ramps are to short and looking at the picture of the front of his variator with the belt on, you can see the wear marks on it. Its like 3/8" away from the top. Adding a shim will make it worse. It needs to be cut inorder to have the full travel of the belt, adding shims will not help him.

[Team-Ty]

Well you can't just shim it if you want to have the full travel of the belt. If you look at the back of the front variator the ramps are to short and looking at the picture of the front of his variator with the belt on, you can see the wear marks on it. Its like 3/8" away from the top. Adding a shim will make it worse. It needs to be cut inorder to have the full travel of the belt, adding shims will not help him.

[Bill Lemans]

Originally posted by Logan #34's Dad
Come-on! Just get on a couple scooter sites and buy a pack of shims made just for this purpose. They come in all different thicknesses to get it just right. Your crank appears to be a 90cc size spline (eton) so it may be a little harder to find the shims.
Try: www.scootercraft.com
I think this will work - you'll have to measure the thickness of the output shaft.
http://www.scootercraft.com/product_info.php?info=p18221_Stage6-Variocontrol-Adjustment-Washers---14-8mm-x-20mm.html
Good luck.

Thank you for that. You would think that the countless hours I've spent reading stuff here, and looking a parts sites, would have turned up that tidbit. I didn't even know they sold them.....:o This is why i keep coming back.My new motto is gonna be "learnin' the hard way":D I want that time back !!!

As for it not being worth it, i did it and it worked. If your just trying to get the belt to sit lower, it works, which is his primary issue. If your trying to get the belt up, it seems like cutting needs to be done to get further roller travel.
Gonna give it a go this week;)

[oldyeller]

I am still taking notes guys thanks for the info..I only have my son half of the time so testing has been kind of slow so nothing new to report..

P.S We did try a short run across the yard again tonight just testing take off..It actually seemed worse with the longer belt..I think this is due to it riding up in the front clutch too much and also it is starting to shift a little before the rear clutch engages..

[Logan #34's Dad]

Hey Yeller, You absolutely do not want the clutch shoes to engage AFTER the belt starts moving. Get yourself one of the koso clutches with the brass weights that can be added and start playing. OR if you have a stiffer torque spring OR lighter rollers. BUT ONE THING AT A TIME.
PM me and i'll give you another "trick" that I do to get more travel.:devil: