Thread: Intermittent vibration at WOT?
02-10-2015, 09:15 AM #1
Intermittent vibration at WOT?
This past fall/start of winter on my last run out with my ski the ski ran great and right as I was heading back to the ramp to have it out and stored for the long winter I gave it a couple of WOT runs. Max rpms on my ski with x charger, 42s, stock intercooler and ecu (other mods are handling mods and such - motor built by Slow91) are 8100-8160 with my 14/19 prop. While hitting WOT I felt a vibration coming from what felt like the rear of the ski. There we're leaves out in the bay as it was fall time so I figured I may have sucked something up. Stopped, sloshed ski back and forth, hit WOT again and no issues.. Right before I was at the ramp, the vibration hit again, I figured it was just more leaves, checked at ramp, no leaves. Vibration was only at max rpm and not until I hit 7900-8100. Drove home to winterize, no leaves in pump.. Winterized ski, it ran and turned over fine on trailer to winterize.. Pulled pump, bearings look ok but grease was grey and had some slight water intrusion so I am rebuilding it.
Motor was built by Slow91, not this winter but the previous with CP pistons, supertech valves, Riva valve train, etc. and all bolts needed to be replaced were replaced, pretty sure newer oem updated flywheel bolts.
I am in the process of starting to get my ski ready for the season and want to know if there is a way to set my mind at ease if it could be an issue with the flywheel bolts or not.. Any symptoms show while running it on the trailer? Could it be the bad grease in the jet pump or should it just be chalked off as mysterious fall time leaf litter giving me headaches and disappearing when I try to clear them from the pump? Motor has about 100 hours since being overhauled by Chris (Slow91) and has ran flawlessly
02-10-2015, 09:56 AM #2
When is the last time you replaced the carbon seal? My ski acts the same way when it's time to be replaced I just put in the new one with the bigger collar and the issue went away.
02-10-2015, 10:03 AM #3
02-10-2015, 10:04 AM #4
pump bearings? my Skat pump did a nasty vibration only wot. swapped pumps and it was fine. replaced the bearings good to go.
02-10-2015, 10:27 AM #5
When you rebuilt the motor I'm pretty sure you went with the oem upgraded flywheel bolts, or whatever you use, I'm pretty sure the only ARP you used were the head studs.. Are you still just using oem flywheel bolts? Think mine should be still be good?
02-10-2015, 01:20 PM #6
the OEM flywheel bolts are good if torqued properly.. The bearings in my pump showed no signs of wear but it was the problem.
02-10-2015, 01:29 PM #7
make sure the prop isnt split, cause mine did the same thing when it happend
02-10-2015, 01:34 PM #8
I would pull the prop too and look at the shaft. Mine started to split and caused a vibration at high rpm, then let go later and took out a lot of other things.
02-10-2015, 02:15 PM #9
Will do, will definitely look closely at the prop once I remove it to rebuild the pump, thanks guys
02-10-2015, 02:16 PM #10
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By Marcpxrs in forum 4-Tec PerformanceReplies: 8Last Post: 04-28-2014, 09:51 AM
By kdaily in forum 4-Tec PerformanceReplies: 12Last Post: 11-26-2013, 01:52 PM
By ktyamaha36 in forum Honda How To & FAQsReplies: 8Last Post: 04-17-2012, 04:09 PM
By hero in forum 4-Tec PerformanceReplies: 12Last Post: 11-15-2011, 06:56 AM
By turbojamie in forum 4-Tec PerformanceReplies: 14Last Post: 06-28-2010, 09:18 PM