To anyone who is still getting notifications on this thread. Finally done with the whole rebuild, two months later and it's purring like a Cadillac. Replaced crank collar, and crank seals and all around which caused mag and pto compression to raise 2 psi cylinders reading 118, 116, 119 m-p. Removed RTV on main cylinder and replaced gasket, was already disintegrating, officially done using that stuff unless service manual says so. Finally, rebuilt the carbs once again with genuine kit which are no longer leaking. And the results!? Well, not in the water quite yet but running it off of the hose it's noticeably much much better already. Took about 5 seconds to start right off the bat after priming by blowing through return lines. With a +1/2 turn on H and L screws to compensate for bore it idles perfectly and starts without a problem. Even revved it a bit without hesitation, buying an actual pop off pressure tester really helped get it perfect. Forgot the PSi but I believe it was a user on this forum who posted his results and I copied them verbatim. Can't wait to put it on the water, I'm pretty positive it'll be near perfect. I'll update once I know, it snowed last weekend but supposedly supposed to be 63F this weekend which is good enough for me.
Thanks to everyone for their help, I owe you guys so much!!!!!
As a quick edit, seals installed by dealer from prior owner never had yama/threebond or grease on ID. Also by looking at the sides of them they are the SBT ones, known for popping out and overall being crappy. New ones are yamaha.
2001 Yamaha SUV 1200
1.5 MM Overbore
Last edited by aedan929; 10-14-2019 at 08:30 PM.