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Mini Twister


gregrob

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Keep in mind, a lot of my advice and ideas are for bada, who's having crank and/or vibration issues.

 

We run engine stays on stock cylinder drag bikes. I consider then an absolute must.

I have a 1/2" thick stator cover, I bolt my stay from the upper chain roller mount (stock frame bike) right to the stator cover. I used to run it to the cases over the sprocket, but I got my cases with one whack.

After my buddy bit it on the ice two years ago, it chunked more of the case so I've got nothing left there to work with.

 

Take a measurement, use two heim joints, left and right thread...and a small swaged rod. Drill and tap accordingly.

 

It should NOT be tight. You should be able to move the stay with your hand or rotate the heims once it's tightened down to the bike.

 

I know that's hard to think about...but think about a heim joint. It twists a little bit even with a bolt through it.

You should be able to twist it that little bit when tightened down...

 

Pour in is the way to go. It just fills the gaps better, period.

 

Some have tried to weld cases...and the issue is they warp. It can be done...but it's not for everyone.

 

Dan @ A&S uses the pour in epoxy.

 

I'm not an epoxy fan, I like welds. But, I also have a bro in law that has been in the family biz of welding for over 40 years. He actually went to school for it and metalurgy, he's not a back yard buzz box arc welder, and his work shows.

 

I absolutely wouldn't run a bike without cushions for the basket. That's probably a big part of the issue right there. Something has to take that shock out of the crank to the transmission, without cushions, that's metal on metal and something's gotta give.

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Keep in mind, a lot of my advice and ideas are for bada, who's having crank and/or vibration issues.

 

We run engine stays on stock cylinder drag bikes. I consider then an absolute must.

I have a 1/2" thick stator cover, I bolt my stay from the upper chain roller mount (stock frame bike) right to the stator cover. I used to run it to the cases over the sprocket, but I got my cases with one whack.

After my buddy bit it on the ice two years ago, it chunked more of the case so I've got nothing left there to work with.

 

Take a measurement, use two heim joints, left and right thread...and a small swaged rod. Drill and tap accordingly.

 

It should NOT be tight. You should be able to move the stay with your hand or rotate the heims once it's tightened down to the bike.

 

I know that's hard to think about...but think about a heim joint. It twists a little bit even with a bolt through it.

You should be able to twist it that little bit when tightened down...

 

Pour in is the way to go. It just fills the gaps better, period.

 

Some have tried to weld cases...and the issue is they warp. It can be done...but it's not for everyone.

 

Dan @ A&S uses the pour in epoxy.

 

I'm not an epoxy fan, I like welds. But, I also have a bro in law that has been in the family biz of welding for over 40 years. He actually went to school for it and metalurgy, he's not a back yard buzz box arc welder, and his work shows.

 

I absolutely wouldn't run a bike without cushions for the basket. That's probably a big part of the issue right there. Something has to take that shock out of the crank to the transmission, without cushions, that's metal on metal and something's gotta give.

 

Yeah, the description of the stay rod makes sense. We will have to fab one of those up and slap on there. Thanks for the tip!

 

I prefer welds as well, but its hard to come by someone with all the tools and means to do aluminum TIG work the right way and make it look good. I did a little bit of welding at the machine shop I used to work in, and I know enough to know not to try and TIG on banshee cases. I'm just not good enough to do aluminum work like that yet. Hopefully some day. So in the mean time, I use epoxy where I need to unless its mild steel or stainless etc.

 

I was pretty unhappy when I saw his basket and all the free play it had in it when he took it apart. I wouldn't think anyone would put together a basket without the cushions.

 

Like I said, if we get the chance to tear it down this weekend I am going to take a LOT of pictures, as a walk-through of sorts. I guess we will find out what really happened then. I'm hoping once we have some pictures to share with everyone it will be pretty evident what went wrong so we can fix it for the next go-around.

 

On your engine stay, did you just drill straight through your sidecover and put a bolt all the way through? I was thinking about getting a heim with a male thread and drill/tap into the sidecover itself, so the heim joint would be in the sidecover, then run a solid rod with a groove cut in it to go around the heim, if that makes sense. Then do the same thing on the frame side with the rod, so it bolts in at the same place you have yours, up on the chain roller. Hope that makes sense...

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You definition of narrow power band and mine may differ.

The bigger the motor, generally speaking the more torque which makes a narrow power band seem less noticeable.

 

Bada...

First thing I'd look for in your bike is the cases and the crank.

It's possible the bore is out of align or sloppy for the crank and/or the tranny.

It don't take much wobble or clearance to start shitting 2nd gears out.

 

I know their full billet trans eats shift forks like a fat kid on a cupcake. I've not heard....however, that the billet 2nd alone will do that.

A bad shaft, fork or worn case could be the reason 5th got eaten too...

Or a poorly cut tranny (not accusing, just throwing out ideas.)

 

Now, everyone thinks the billet 2nd gears are drop in, they're not. They have to have the matching/mating gear backcut to match. That could be a problem??

 

I'd also look at your crank. Have someone that knows what they're doing, perhaps crankworks or twister, check the balance on it.

 

Most of the time, you get it to within .003 to .005 of being true, weld it, done. Truing the crank does not check balance. That could explain the violent shaking, etc.

i put a new crank and new rods for the shift forks, the billet second gear was not broken but it did have very worn dogs so i replaced it with a stock gear.i have had my twister to the dunes 2 times aftyer replacing those parts and i have not had any problems i also change from pvl to stock ignition.however those 2 times that my bike saw the dunes i only made no more than 5 passes combine.so ill just wait and see if it will hold up...if not dave ill have to give you a call..thanks for the input

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15K posts, like I said, get a life.

 

 

Thanks JD. I didnt "start" anything and shouldnt have to explain every little thing I see. I guess some people are simple that way tho. (Not you)

 

Thanks again for replacing that grille for me a while back. Youre a great guy and do great work.

 

 

Thanks man, Im here if you need anything... I have a lot of new products out that I am trying to get the word out for... Check my site!

 

 

.....Looks like everyone is starting to get a long and talk about some good stuff.... This is nice :P

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Like I said, if we get the chance to tear it down this weekend I am going to take a LOT of pictures, as a walk-through of sorts. I guess we will find out what really happened then. I'm hoping once we have some pictures to share with everyone it will be pretty evident what went wrong so we can fix it for the next go-around.

 

I would like to see some pics of the tranny right after you split the cases, before you really touch anything so we can see what happened.

 

 

 

We run engine stays on stock cylinder drag bikes. I consider then an absolute must.

 

Got any pictures Dave?

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I would like to see some pics of the tranny right after you split the cases, before you really touch anything so we can see what happened.

 

 

Yeah, I was planning on it.

 

We got hit with a bunch of snow last night and everything's a mess. I've got to replace a fuel pump on my truck first thing in the morning, then if greg can make it up here to my place we will start tearing everything apart.

 

- Jared

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Yep...I'm too lazy to go in the garage and take a fresh pic, I'm on a vaca day dammit...LOL.

 

Here's a pic from the back 1/4 of my bike, you can see it pretty clearly and get the idea.

pict0006k.jpg

 

 

Cool design. I like it. Do you run a wheelie bar at the track? What do you have the weight down to on your bike?

 

- Jared

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Yep...I'm too lazy to go in the garage and take a fresh pic, I'm on a vaca day dammit...LOL.

 

 

On a stay-cation? LOL. I am guessing that is going to stop the engine from trying to pull towards the rear sprocket and take some stress off of the cases? This is the first time that I have seen something like this, do a lot of guys in MI a similar getup?I would think that the motor mounts would do a good job of keeping the motor were it needs to be and that the bearing support would take most of the load/stress off of the cases. Maybe I'm wrong or maybe its just cheap insurance. Thanks for the photo and good info Dave.

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The stock motor mounts are designed to hold 35 or so HP. They do a fine job of that.

 

Triple or quadruple that....no so much anymore. When you hammer the gas, the sprocket side will get sucked back by the chain toward the rear axle...this prevents that.

 

Yep, we all run it...

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