Thread: Group K Ride plate mod for 250X
02-20-2007, 11:16 AM #1
Group K Ride plate mod for 250X
Here's the news from Harry, borrowed from his post on PWCToday.
"In the last weeks we have been testing with an Ultra 250 to be raced in the 6 Hour race at Lake Havasu on Feb 24th. Since reliability and longest possible fuel range are top priorities for this race, we did no engine compartment mods ... but found speed in the ride plate.
By the time we were done, our 4th version of the ride plate modification netted a 2mph increase (peak rpms were the same). We also installed the LX nozzle wedge to gain another mph on top of that. With the Stage-4 ride-plate mod, and nozzle wedge, the boat still handles and turns great. The elevated nose height of this setup makes the ride through rough water a whole lot less punishing as well.
With the reduced water contact surface area, it's reasonable to expect that high-speed fuel ranges will be increased slightly... but the 6-hour will tell us for sure.
The Group K Stage-4 rideplate mod is available for $140(3-5 day in-house turnaround), and the nozzle wedge is available from your Kaw dealer.... It's the cheapest 3mph gain you'll ever get from an Ultra 250.
Respectfully, Harry Klemm
Unless otherwise stated, responses to all forum posts are based on my personal experiences working within the PWC industry, and developing high performance PWCs since 1987.
02-20-2007, 11:21 AM #2
Damn, we must have been typing at the same time! Our posts are both at 10:16
02-20-2007, 11:28 AM #3
While you 2 guys were typing the same info at the same time I was looking up the cost of a new OEM ride plate for the Ultra. (otherwise we all would have submitted identical posts at the same time !) The rideplate retails at $99.92 Part number 59446-3759. If anyone wants one to send to Group K for their stage 4 mods, I pay $68.94 for the plate. With an extra one you ski won't be out of service waiting for the modded one to be delivered. Add that to the $140 Harry gets and it's still a bargain for a reported 2 mph increase.
Last edited by way2fast; 02-20-2007 at 04:14 PM.
02-20-2007, 12:47 PM #4
So does this mean we are now over 70mph on the 250x for under $200... with no engine work.
02-20-2007, 04:36 PM #5
- Join Date
- Sep 2006
- S. Florida
Interesting. Adding this of my list of things to do to my 250x after it is broken in.
I need to buy a gps as well.
02-20-2007, 04:40 PM #6
02-20-2007, 04:48 PM #7
This is great news, and Harry is usually conservative, or at least truthful.
I friggin' knew it. Wait til someone really gets that boat lifted. There's more there.
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By ZMANN in forum Yamaha Old School SkisReplies: 1Last Post: 05-03-2008, 12:53 PM
By shooter98xpl in forum Yamaha PWC Performance (2-stroke)Replies: 12Last Post: 02-22-2006, 12:00 AM
By nitro rxp in forum 4-Tec PerformanceReplies: 3Last Post: 08-13-2005, 01:00 PM
By 01xdime in forum 4-Tec PerformanceReplies: 8Last Post: 08-11-2005, 02:43 PM
By Krazy-K in forum 4-Tec PerformanceReplies: 8Last Post: 06-21-2005, 05:10 PM