Finally Austin/Yamaha test drive time...clutching way off

[Seann17]

OK, "IF" I decide to lighten the weights, (after spring test) which rivet should go first?

 

[Yamajon1]

Install the lighter spring and test drive it to get a baseline to go off of. Then evaluate what it’s doing versus what you want it to do. Generally heal weight or closest to the pivot point effects engagement, center weight midrange and tip weight top end but the profile and total weight also need to be considered. It’s trial and error with lots of testing. As said before change one thing at a time so you learn what change made what difference. It’s a balancing act between spring rates, weights and roller diameters in the primary and secondary spring rate and helix angles. I have no experience clutching any wheeled vehicles but the principles are the same. Maybe the SxS guys have some more knowledge on this.

 

[Seann17]

Good info...with my road racing background, I'm with you on only changing one thing at a time. First time I've heard mention of roller diameters/effect, have to read up on that. Will post with softer spring update.

 

[Seann17]

Tried what looked like a short white/silver/white spring (from dealer junk bin)...brought engagement down to 32-3300 (better, but not enough), preload is same at 35 by the chart. I’m going to keep testing...look for something with preload of 15 (e.g. white/gold/white), 20 (blue/blue/blue), 25 (blue/yellow/blue) & 30 (blue/pink/blue) preload to try. Good start though. Didn't rattle with the shorter spring. I'll try and take it down the road tomorrow (raining here).

 

[mysledblows]

I might still have some short cover springs in a box in the shop. probably not in the 15-20 preload, but might be something in that 30 range. I'll let you know if something looks useful.

 

[Seann17]

I've ordered a blue/blue/blue (short) 20 preload, will share results....

 

[Seann17]

Update...got the blue x 3 spring, I can crawl around at 2500 (not bad) but the engagement is still similar, too high. This spring has a 20 preload, thought it would make more of a difference. Time to start lightening the weights I think...any ideas for starting this process?
Thanks,
Seann
mocking up extractor fans for "trunk"

 

[sxr70001]

I think heavier weights would bring on earlier engagement, but if you want to lighten them you could just start by drilling a hole in the weights. Try to keep all the arms the same weight.

 

[Seann17]

OK, maybe I should have said "adjusting the weights" instead of lightening the weights...all new to me. How do you go heavier if that does bring in the engagement?

 

[Seann17]

Also, does anyone know what the gap should be for the speedo pickup? Made mine adjustable, don't know if the sleds were...I have a cheap gps gauge but would like to see how accurate the stock gauge is with this setup.

 

[maim]

start with the rivit closest to the heel. that will bring engagement down a bunch.

on my apex, the speedo pick up is about the thickness of a playing card away from the tone ring (toothed gear).

 

[Srxspec]

Removing the rivet closest to the heel will not bring engagement down, that will actually raise engagement. If you want to bring engagement down, remove the tip weight (furthest out from the pin). This will allow the weight to swing out sooner and engage at an earlier rpm.

 

[Seann17]

OK, anybody want to break the tie on these two opposing suggestions?

 

[maim]

srxspec is right. i had a brain fart.

 

[Seann17]

OK, top rivet coming out for tomorrow...test drive #4