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Showing content with the highest reputation on 04/20/2020 in all areas

  1. More recent pic of the updated $30 steering wheel, with quick release I had lying around the shop. The stock steering wheel was like some Fisher Price thing. Not ideal at full clip on the trail lol
    1 point
  2. -----First my required disclaimer: Don't try this at home!! ----- Now with that out of the way: Here is a 'drivability profile diagram' (Reference: Olav Aaen''s vey informative Clutch Tuning Handbook for the scoop on the math behind all this - or this link: https://web.wpi.edu/Pubs/E-project/Available/E-project-022014-185837/unrestricted/MQP_Timothy_DeGreenia_Edited_Jan19.pdf ) Just to give an idea of the empirical 'shift out' with the CVTech in 7:1 mode, just subtract 10MPH from the numbers shown in this graph. (this graph shows the gear ratio 10.15:1 we are using which adds 10MPH to all ratio points in the graph over stock gears) as stock may be 13.25:1 final drive in these buggies. Stock top speed for most these UTV's is 25MPH at 3800RPM - = .75:1 final CVT ratio with 13.25 final. Full stroke allows it to pull to .45 (give or take a couple points due to belt slippage, heat, etc.) at the shift out RPM. Now this could potentially stall/bog stock engines, (we have not seen this at all) but with a 650cc or larger, should be fine. Not like the clutch is being re-calibrated - just allowed more 'shift out' which holds the engagement or governed RPM more consistent with more pull on top. Of course I don't suggest driving one of these buggies at 50+MPH, (or try!) the idea is full use of the CVT ratios. Much like going from a 4 speed manual, to a six speed manual with some more gears for lugging the engine along.
    1 point
  3. Update on the swap. Since getting the new engine spun up, and dialing in the Mikuni, we have been putting this buggy to use! After a good snow storm, it proved to be handy to have to go clear broken branches and fallen trees in the area. and on our property. I could tell right away though something wasn't quite right with the CVT, it would 'shift out' and the motor would just wind out (as in 5K+ RPM) too high in other words at an anemic 20 MPH tops. Once all the work was done I learned all about this CVT setup. Here is what I learned, and this should apply to all CVTech PWB50/80 type CVT setups for reference. I did the pen mark on the driver(primary) sheave to see what was up with the primary clutch pully, and it was only climbing out with an inch or more of the pen mark left. So I ordered a new Kevlar belt, turns out the original belt was worn about .032" or more, and the new belt being wider will climb higher up the sheave making it more efficient at least. While I was at it I decided to pull the driver pully off, and clean it up, document the spring, blocks, weight, and make sure everything worked - I suspected it was jamming up on the stationary sheave binding the sheave stroke. But I came to discover these clutches have a "Stroke limiter" ring, that stops the sheave stroke about .250" short of the full stroke. Since CVTech specs these CVT's with a shift ratio of 6.97:1 - (3:1 - .43:1 ratio range), with the limiter ring in there it limits the clutch to a 4:1 shift ratio = 3:1 - .75:1 or so depending on belt, spring, etc. So after reading the service information and some trial and error, mock fitting the belt to the sheaves and checking the belt position to full shift out, I removed the limiter to allow the full shift ratio of 7:1. To make a long story short - not only does it haul wood really well, now it hauls ass! lol The grippy belt with full sheave stroke is a night and day difference. The shift out is slow and mild, but the motor pulls down much better - no more crazy RPM to gain a cruising speed. So for anyone with a CVTech Powerbloc 50/80 (aka series 0400/0600), CVT and you need to gain about ~10MPH net speed increase, worn belt or not just remove that limiter ring. (The REAL benefit of this: will help give the belt more usable life with full sheave stroke, and mellow out the engine RPM) while cleaning the primary pulley assembly -- if you have one of the ASW/Landmaster, BullDog, Land Pride Trekker, etc. utility rigs (not sure what all this clutch setup comes on). I imagine it was up to the manufacture to install some type of limiter or not as the manual says (1 or 0) so it's not needed for proper clutch operation. I don't know why they cripple a fairly decent clutch like that, I imagine for some 'saaaafety' regulation, but it really makes the drive setup very inefficient. Once the weather gets a bit more decent we plan to shoot some video of it running. for the amusement of the five other people that own one of these Has come a long way since dragging it home! Anyway I hope someone finds this tip helpful, especially if you are going through a lot of belts. I attached a diagram showing the limiter and a couple pics of the process.
    1 point
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