I have had a few test ride around the block and my upgraded 351cc engine seems to be running reliably now, so I think I'm going to take it out for a test ride over the weekend. Before that I believe it is advisable to put heavier duty springs in to help minimise the clutch slipping under acceleration. So I bought a set of Barnett heavy duty springs.



Putting the heavy duty spring (top) next to the stock spring (bottom) there is no obvious visual different, but squeezing the springs using my fingers you can definitely tell the Barnett ones are harder to compress.



I actually have a full set of replacement clutch plates and springs off RMATV, but I will only install that later if the stock clutch is too worn. The manual has instructions for measuring if the clutch plates are worn enough to need replacement, but I wasn't feeling motivated to do that so I'll just stick with the original plates with heavier duty springs for now.

Under the clutch cover the clutch is like other manual clutches I guess.



The "Throw-out" (I think that's what it is called) and and washer come off easily.



Removing the 6 bolts holding down the pressure plate reveals the springs that need changing



Switching the springs over and bolting everything back together isn't rocket science. The lever feel might be marginally stiffer, but I can't say I really noticed much of a difference. Taking the bike out for a test ride went fine and the clutch seems to be working nicely... so now we just have to take the bike out for a proper test ride. I'm looking forward to Saturday!

 

Oh yeah. The EBC dirt racer clutch and the Barnett springs are the combo that I found is the best for the 351. I did a lot of experimenting a few years ago with clutches, and this is the best! Good luck.