Stalkaholic
12-21-2007, 04:34 PM
As a lot of you know, the first test drive of my newly rebuilt Marlin did not go so well. The suction housing broke and I almost sank my boat.
What happened was when I installed the wearing (stock shoulderless wear ring on a lipped insulator), the part of the insulator that butts up against the thrust area of the suction housing was sticking up (there's always a little bit of excess in that area). I did not trim this excess off after I installed the wear ring, and I also never checked the thrust clearance to catch this mistake. I remember when I spun the shaft by hand there was a spot where it would drag on something, but I figured this is normal since they do call it a "wear ring". However I learned the hard way that this is not correct, and that the pump should spin freely and quietly when properly assembled.
What I think happened was the thrust face of the impeller ripped off pieces of the excess insulator on the thrust lip of the suction housing. These pieces got caught between the impeller and wear ring, heated up, which hardened up the pieces. These pieces started gouging away at the impeller and caused pieces of the impeller to start doing the same thing. At one point, the pump tried to lock up, but the engine "torqued" it out of lockup. This excessive force applied to the locked up pump I think is what broke the side of the suction housing. This is the only logical explanation I can come up with based on what we found when we took the pump apart.
However, thanks to R.A.D.Man fronting me a suction housing, Tom at JBP for hookin' me up with all the parts I needed, and Beerjet for helping me rebuild her for the second time, we had her back on the water for Labor Day.
This thread is a rather interesting read of what we found and how we rebuilt it. Originally typed by Beerjet on SoCalJetBoats, I have copied and pasted it here for all to see. Enjoy! :D
What happened was when I installed the wearing (stock shoulderless wear ring on a lipped insulator), the part of the insulator that butts up against the thrust area of the suction housing was sticking up (there's always a little bit of excess in that area). I did not trim this excess off after I installed the wear ring, and I also never checked the thrust clearance to catch this mistake. I remember when I spun the shaft by hand there was a spot where it would drag on something, but I figured this is normal since they do call it a "wear ring". However I learned the hard way that this is not correct, and that the pump should spin freely and quietly when properly assembled.
What I think happened was the thrust face of the impeller ripped off pieces of the excess insulator on the thrust lip of the suction housing. These pieces got caught between the impeller and wear ring, heated up, which hardened up the pieces. These pieces started gouging away at the impeller and caused pieces of the impeller to start doing the same thing. At one point, the pump tried to lock up, but the engine "torqued" it out of lockup. This excessive force applied to the locked up pump I think is what broke the side of the suction housing. This is the only logical explanation I can come up with based on what we found when we took the pump apart.
However, thanks to R.A.D.Man fronting me a suction housing, Tom at JBP for hookin' me up with all the parts I needed, and Beerjet for helping me rebuild her for the second time, we had her back on the water for Labor Day.
This thread is a rather interesting read of what we found and how we rebuilt it. Originally typed by Beerjet on SoCalJetBoats, I have copied and pasted it here for all to see. Enjoy! :D