I am working on an Mxz 800,all stock except for 25/43 gears,50-44 helix and 1.25 track.All is well except when I pin it off the line the rpm's jump to 8200 and then eventually around 80 mph settle to 8000rpm.I have tried adding more weight to the lower hole to no avail.I put a felt mark on the clutch and it rubbed off right to the top everytime.Could this mean I could pull another tooth up top,it tops out at 170 kph consistently.Is the over rev off the line an issue or should I just leave it and what do you think of the gearing? Any one?

Put your 53 start angle helix back in to load the motor at the start of the shift.An over rev at any point of the shift is no good.

Going to the 53 angle Motor'n suggests will pull you RPM's down, and is a pretty good settup, as I just ran it last weekend, but you want to make sure the rest of your settup is close, because you don't really want to tune RPM's with your secondary. What weights were you running originally at both locations? What about your pins? Did you try adding another washer to the upper hole (closest to the pin?)

:hallo1:

When I started with the 53/47 I had 8 grams in both the top and bottom hole's.Used hollow steel pins. Tach would read 7600 rpm on launch and drifted up to 7900 at full shift.I proceeded to the 50-44 helix after that with 9.8 grams in the top and 8 grams in the bottom.Fom a dead start tach goes up to 8300 and eventually settle's back to 8000 at full shift as mentioned in first post.Again used hollow steel pins (10 grams).

I sent a message back to you, but try 7.6 grams each location, keep 10 gram hollow pin, clicker 2, 53/47 with doo white at A-2.

Let me know.

w00t

I have also been dialing in the TSA. What I have noticed was weight added to the lower holes doesn't affect rpm as much as the same weight added to the holes closest to the pin. In fact I have had to add weight to the back of the upper hole which should be ok to do.

Doo hollow pins are 10 grams and I believe Goodwin hollows are 11gr. I swapped the doo pins for the gw to put more weight on the tip. It also gives you room to add more tip weight. I still tried to keep the tip weight under the stock 16 gr pin weight to keep the advantage of the TSA.

Hope this makes sense, still learning myself.

Look how much total weight you ran with the 53/47 helix.8 grams in each hole plus 10 grams pin. A total of 26 grams. Put the 53/47 in and remove weight from the arms.Run the secondary pull off at 21 lbs,don't just go by the numbering chart it's not always what the poundage scale will read.Your 800 has a lot of bottom end torque,and shoudn't have a problem pulling a 53 angle with the primary set up right.

Hope I'm not butting in, but as I mentioned earlier I am still learning myself.

If 800 x has the TSA-295 the arms weigh 30 gr +8+8+10=56gr total

stock arms are 39 gr +16 solid pin=55gr total

Isn't that like adding 1gr?

just trying to understand

sorry TSA 290 arms are 30gr

TSA 295 arms are 37 gr

I'll try some different things and then get back to you guy's with the results.

Super7, don't ever think you are budding in, this is why these forums exist. Please give us any and all information you may have. I have had these arms for a few seasons now, but never really had the snow and ice conditions to really spend a day running different settups. Now we have the conditions, and I am still finding it hard to spend a lot of tuning time. With a wife and kids, my time is limited, and I have been choosing to ride instead of wrench.

In any case, I spoke with Bill Cudney via email yesterday, and he is suggesting an aluminum bolt and thin washer on the back side of the top hole, in addition to the 5.8 gram brass bolt, thick and thin washer. My arms aren't tapped all the way through, but maybe yours are. Try it and see what happens. He also said 5.8 gram brass bolt and thick washer on bottom, hollow 10.3 gram pin.

Keep this post alive. I think a lot of guys gave up on these arms, but I think there is something there. I know my sled runs great out of the hole, and midrange is real strong. My sled even sounds different, backshift is excellent, and I can hit my rpms immediately at any speed when I nail the throttle. I think there may be a bit more slippage on the high end, and playing with weight in the top hole or even the pin should do the trick.

Super7, to answer some of your questions above, even if you ended up with the same weight with the thundershift arms vs stock arms, you are still changing the shift characteristics because you are locating different masses of weight at different arm lengths on a fulcrum (arm). That is also why changing weight on the top hole makes more of a difference than the bottom hole, there is a longer arm or leverage point. Think of the teeter-totter or a pry bar. Its much easier to put leverage on a pry bar when you are farther from the pry point.

If you guys are threaded all the way through on your arms, maybe try the lower hole with your weight under the arm (pushing) and your top hole weight on top of the arm (pulling). I think the difference between pushing and pulling the arm should have a little attention.

Hope this makes sense.

:cussing:

I understand how the placement of weight would affect the shift characteristics. I think when large gram weights are mentioned on these arms you have to understand that the arms are actually about 9gr less than stock. I personally like the arms and have not had much trouble tuning them. My motor is not stock and I'm running around 93 foot pounds of torque at 7500 rpm. As you know most clutch kits are tuned for stock sleds at 7850 rpm. This is why I had to add weight to the back as well as some in the pin. Between the Goodwin adjustable pins (16 gr kit) and the weight placement on the arms it is very easy to achieve correct rpm. Shifting weight around now thats another story. Seems to be infinite combinations.

Super7, it sounds like you know what your doing. You must have the light arms (30 gram). Your weights mount horizontal in the arms, and not vertical like mine, so the top or bottom isn't an issue for you. Have you ever tried running the arms empty, and loading up your pin, like a mag or composite arm settup? My arms are 37 grams, and I weighed my stock ones at 41 grams. Have you tried any of the oversize rollers? I have had some luck with them on the stock arms.

800 x,
Today I switched from a 52/46 helix to a 54/48 and ran into the same situation you have. rpm's went over when throttle was pinned then settled about 200 rpm over my target. What I ended up doing was change my clickers from #3 to #5. The rpms didn't jump around as they did on #3 but I was still over reving. Added weight to get desired rpm and all is good. Try to find the clicker position that works for you then add or remove weight as needed.

legolamb,
I do have the light arms. I have thought about running the arms empty but came to the conclussuion I would have to add to much weight to the tips. I now have 15.4 gr pin weight, 9.1gr in top hole, 8.6 gr in lower hole, and 6.2 gr in back top hole. Thats 39.3 grams on the 30 gr arms. I think Goodwin heavy pins only go to 21.2 gr. I really don't like running so much weight. With less weight the belt does't go to the bottom of the secondary. Maybe the secondary spring is to stiff 205/315.
Maybe it's ok to use that much weight in the primary I really don't know. It seems to be hard on belts. My clutch temps are not all that hot other than the fixed side of the primary. ( wish I could figure that out.) I have only been messin with clutches since last year and have been basicly tuning what I have.

Good info guy's,I rode all weekend with the 50-44 helix and it is not the way to go for me.As time permit's this week I will throw the 53-47 back in and try some of those weight combo's Legolamb got from Cudney Racing.Thanks again for the info.I will put another post up on wednesday when I try the 53-47 again.Stay in touch.

I ended up with a few hour's of spare time today and tried Legolamb's set-up from Cudney Racing.I went back to the 53-47 and had good results.I now have it set in clicker #3 and am just a tad shy of 8000 right through the shift.I will take out a thin shim out of the top front and it should be good from there.Thank's for everyone's input.One thing I noticed when I was changing helix's was the new secondary button's I put in 600 mile's ago have taken quite a beating and were wore down a good 1/16 or more.

800 x, Glad to here things are comming together for you.
Just an update on the helix change from 52/46 to 54/48 on my sled. The switch was just what the doctor ordered. I run a slightly modded 02 MXZ 700 the sled did very very well at the lake I was at Sunday. I also deal with Bill.
Thanks Bill

Glad to hear both of you making progress. Super7 are you still running the heavier weights you mentioned earlier with the steeper helix? I got to snake out sewer drains all day Saturday, what a frickin blast that was.

w00t

legolamb, Yes, I am running the heavy weights and 54/48 helix. As I posted to 800 x, the switch to the 54/48 was a breeze to dial in. Had the secondary off once to change helix and the primary off once to add weight. Seems like any time I make a change I am always adding weight. I think I just added the last gram.

The racing around here brings out all the best tuners. I have run against some very stiff competition. I'm talking about any where between 50- 100 sleds from a 60 mile area to give you a idea. Any body that has anything to run usualy shows up every Sunday. I don't know how to explain without sounding like I'm bragging but in the 700 and 800 class there was only ONE F7 and ONE Rev 800 faster this Sunday. I must have raced 45 sleds of different brands. I can not beat 800's with big bores but have beaten many 800 piped sleds. My 700 suprized a lot of bigger sleds. We race hardpack about 1200-1500' I don't think I can get any more out of this sled.

I have 03 800 rev and i am running thunder shiftkit as well but just pins
and i run 26.6 grams with stock arms my rpms are bang on all the way threw my shift 8050 to 8100 clicker#4 if that helps I find pulls harder with weight at the tip
:devil:

Thats great Super7, glad you are dialed in. How is your clutch heat with that helix? That is one thing I have been chasing for a few seasons, even with regular arms and pin weight.

Satan660, glad to hear you found a good settup. You are using the more traditional approach of just adding pin weight to get better low and mid, but I think the TRA tends to overshift at higher ratio's (.83 to 1) and you lose efficiency on the top end. The adjustable arms are in theory are supposed to correct this problem by placing weight mass at two other locations on the arm, not the end where your pin is. Both settups work, but which one is better?????? Still testing!!!

legolamb, My secondary is cool, outer half of primary is warm and the inner half of primary is hot: confused:

I am a firm believer that the TSA help midrange and top end. I don't know if it's the porting or the arms or even a conbonation of the two but my midrange is unbelievable. This is where my sled shines. Most of the weight is applied on the upper hole front and back without neglecting the pin to much.