1996 gen vi 7.4L impeller replace short bolt

Browja66

Cadet
Joined
Jul 4, 2019
Messages
11
Hello I searched forums prior to doing this job and it was very helpful. Seeing as I have a 1998 tige pre2200 v-drive with a 1996 gen-vi mpi plumbed with ballast which makes doing anything in the engine really fun on a 6’2” guy. It’s a new to me boat so still figuring out its quirks. It seems to like country music and running in less than a full tank of gas. Tends to lock up on hot days and think I have that figured out with running the vent fan and Opening throttle on hot days. Well last weekend went to start up after emptying ballast and had good belt squeak and temp started rising. Belt squeak stop temp went down. I know PO tightened belt so could be a belt but also I know it was due for impeller. PO did it year before. So dove into impeller change. Btw ran boat this weekend and no belt slippage or issues. I got the impeller housing off and the impeller looked fine but replace anyways. Went to put back on and I have one bolt shorter. I suspect it goes into the impeller housing on the backside close to engine that I cannot see (again v-drive). The parts diagram is not much help as it shows one bolt not all of them. So the PO was very mechanical took good care of the boat but I am not sure if this short bolt is a mod or if there is indeed a shorter bolt on this setup. The outside bolt has a bit on it and I thought maybe there was suppose to be a nut on the inside housing bolt but II couldn’t feel one and good thing as it would have been next to impossible to feeel back there and get a wrench on it. Any knowledge on the 1996 gen-vi mpi impeller bolt arrangement and if there is a shorter bolt on that engine side would be helpful. Diving back into the hot ski/ballast compartment to see what I can figure out.
 

Browja66

Cadet
Joined
Jul 4, 2019
Messages
11
I went to boat service shop and the parts guy looked up the impeller kit and that wasn’t much help as it comes with 7 bolts 5 long 2 short. I ended up getting a 3” 5/16-18 (split the difference) and seems to work fine. So my old impeller was not that bad but the boat is running cooler with the new impeller and it seems to like that 168-170 degree range along with country music. I think I will change the impeller annually versus the PO was doing semi annual. It likes a firm impeller!
 
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