Hey guys, I believe I've got a few issue's with my 12JG, attached to a 454, and that's attached to a 3800 # 26' sleekcraft. Being my first boat (and jet) it seems to take feathered throttle motions to keep rpms down (with what I would call cavitating) to get it to go anyplace. I may be jumping the gun here, I have not taken it apart yet, but, here is what I've noticed. Impeller (cut?) is a little chipped (seen worse). Water leaks around rope packing shaft in to the hull (can get it to quit leaking by snugging down the two nuts, but after a run, it leaks again and after repeating on a Saturday, no more adjustment). Also, when I service the bowl ( 80-90W) the first start-up blows a water-oil mixture all over the floor. Other than those things it seems to run on the water well with LOTS of patience. I'm looking to get your help on the matter, as I would love to fix the problem or take part in your exchange program.
Many Thanks, Chris
Last edited by nelsont509; 06-27-2011 at 05:50 AM.
Welcome to jet boating. Some things to start looking at; The leaking at the packing gland and cavitation sound like the packing is worn out or may be glazed. Suggest you remove the old and replace with new. While you have the packing out you may want to try to see what the condition of the shaft is where the packing rides on the shaft. It may be grooved badly either due to wear or improper packing adjustment at some time. Service the bowl? Are you removing the second fitting when adding the lube? If not, you may be pressurizing the bearing area and pushing oil and water past the seal. Not final answers but some points to start from.
Thanks for the quick reply!! I've heard that my pump could be sucking air where the packing goes. I wasn't sure but I'll be sure to check the shaft for wear and replace the packing. Yes I do remove the other plug when I fill the bowl. I think I fill left and watch the right. Is this not correct??