Just when i thought yama engineers could do no wrong..except for powervalves...and pump plug kits..
The 97gp12 impellar shaft has a nut on the pump end under the grease filled plastic cone. It is the highest torque spec'd item on the whole dang assembly.
Yet my 97 venture1100, same pump, has no nut at all! Threads are there..but no nut!!
I was changing impellar and thought the factory forgot the nut! But after checking both factory service manuals, gp12 and venture11 sure enough in the pic it shows a nut for the gp and no nut for the venture!
Should i put a nut on the venture anyway???
thanks for your opinions, Dave
Posts: 2624 | Location: Louisville,KY/So.IN | Registered: August 04, 2001
I'm just thinking out loud here... it doesn't seem that that old Venture would be capable of generating the same type of torque/power that the GP can. The nut is probably Yamaha's way of strenthening up the pump system to take on heavier loads. I'd leave it alone.
On the other hand, if you want to get a nut, that is not within the scope of this forum, and no bodies business but your own!!!
Salty
this thing is killing me!!!
Posts: 341 | Location: Texas City, TX | Registered: October 26, 2001
LOL..thanks Salty...haven't had a nut in a week cuz i been so tied up with these skis...
my venture has a head, f/a, and a 13/19 prop..so i was thinkin' about the nut..
last night i was changing the head on my gp12 and piston #2 was in low position so i put a shop rag in it to keep debris out while i scraped old gasket off and then put the new head on and gave it a crank. Oh chit. Luckily only a partial crankover but it stopped the piston like a hydrolock..pulled the head and the towel and ran it up and down by hand and all looks good..just hope crank isn't bent..how would i tell? comp is 150 exactly on all 3 cyls now.
gonna get a nut tonight. Might get one for the venture too..
Posts: 2624 | Location: Louisville,KY/So.IN | Registered: August 04, 2001
that nut keeps the prop fro driving forward and ripping the motor off it's mounts as it chews throught eh bulkhead and the pump shoe. Ask me how I know...... the nut is a simple item that is supposed to be on all yam. pumps that call ffor it. I have had thte same thing happen to a vaveventure 760. That nut was not properly torqued. 50lb? and use red locktight. there should also be a washer in there. As for the checking for bent crank, do a search or checking crank index or checking for twisted crank on theis forum. Fercho found a brilliant image showing what to do and hwe and I have posted it sevetral times now.
Posts: 603 | Location: Bermuda | Registered: January 11, 2001
RIVA Performance Forums 
Luckily only a partial crankover but it stopped the piston like a hydrolock..pulled the head and the towel and ran it up and down by hand and all looks good..just hope crank isn't bent..how would i tell? comp is 150 exactly on all 3 cyls now.
