10-10-2006, 02:17 AM #1
Another old GP1200 trying to keep up with the big boys!
Well i went out today, not the best conditions with fairly strong cross winds and 6-8inch chop.
About my ski,
Jet works valve on the stinger,
Air filter turned so intake is against the hull,
Primer kit, butterflys removed.
That's it on the motor.
R&D scoop grate (sealed inside as well)
Riva performance ride plate - 2 washers
Worx Sponsons (set low)
Solas XO, stock pitch.
Wet Wolf AAT cone (3rd smallest shuttle)
Spout blocked off.
Blueprinted pump, (myself)
Bored exit nozzle - 1mm overall.
61.7 @ 7000rpms trim set at neutral.
I hope to slowly go up in shuttles size's which will drop the rpm's, without top speed dropping off.
The best speed I did before any mods were done was a 58.3 @6890 ski was stock.
Am very happy with that result and think I can get it better with fine tuning the AAT cone and removing a washer on the ride plate, smoother water with the trim set down 2. (bow up) and lifting the sponsons up. Still have to seal up the bolts holes and get some trim tabs....ah Bill!
OH and other thing.... "How the hell do some of you guys take the photo's while still on the move"?????
10-10-2006, 02:59 AM #2
The cheap way would be the Tony Hawk Helmetcam.
Your air filter sounds interesting it sounds like carbs are in stock position but box is on 90 deg elbow extensions.
Does this leave room to get to the carbs adjusters.
Are your speeds low on gas or full tank
Are you on the seat or in the superman.
10-10-2006, 03:30 AM #3
The air filter box is just turned 180 deg and bolts back on as normal. Just thought cooler air would be drawn into the carbs instead of been above the head which you would think would be hotter air getting sucked in.
I knew I forgot something... butt on the rear seat with nose on steering pad....well just about on it!, if I moved back I would start to skip over the chop and have a empty pump for a second or two, made it alittle awkward to stay nicely on the seat. hence set in neutral as I would start that famous riding bull ski.
Gas tank had 2 bars which must of been close too 1 1/2 as when I got back in only one bar showed.
Tony Hawk Helmetcam.... cheap are they?? seen some helmet cams here for $680 NZ hmmm.
10-10-2006, 06:43 AM #4
got my tonyhawk helmet cam shipped to my door for roughly 50.00 used.
new they run from about 65-85.00
10-10-2006, 08:19 AM #5
Great numbers you are seeing improvements over last time out. I talked to Pistonwash a few weeks ago and he stressed how important the truing of the hull is on these models. He also said learn from what the GPR guys are doing make sure as you go back on the hull each transition has a step and there are no edges to grab water and rob speed. Spud was over last night made the same comments about edges and once again pointed out the cutout for the speedometer told me to chamfer the rear edge of it. also fill the holes in the nozzle visibility spout and bilge pump with JB weld or similar product and smooth out. Install an electric bilge pump for handling the water in hull. also Spud suggested experimenting with stepping or angling the sponsons like on a GPR. There has been a lot learned since guys put these older rides to bed and went to other platforms seems to me from what I have read here over the past year is that the biggest gains came from proper hull set up.
link to Pistonwashes hull truing and some other great tuning advice
10-10-2006, 09:55 AM #6
10-10-2006, 10:58 AM #7
Very good numbers GPKiwi, in better conditions I would say you would be at 64.
10-10-2006, 02:47 PM #8
97sleeper... yeah would love to hit around the 64 and think your right better conditions it shouldn't be too far off hitting 64.
Bill yes more work around the hull would pay off for sure,hope to get it setup with ride plate angles to get the best in all conditins which may not have the best top speed, but better all round, then seal all bolts up etc. Have the spout blocked with some stainless rod pressed into the hole and cleaned up the inside of the rod to make it smooth with the nozzle surface. but not the bilge spout, never quite sure where to place the bilge pump...so thinking on that one.
I will tonight clean up around the speedo wheel area and go out tomorrow and spend most of the day out.. it's a awesome morning here but have to take my daughter on a school trip so the day is buggered!! (Wednesday morning here now)
See Darthraider machined his Riva plate flat as there is a hook in the center part of the plate, which I will get done next week when I am at work.
Some pic's, see the arrow, this area here had a lip and I also matched the top of the shoe from the intake grate, as it sat lower than this ring with about 1-2mm lip at the top of the shoe sides. (can't see that) I placed some felt packing along the shoe edge which made it a tight fit inside the ducting, then placed silicone to fill in the gap as so it wouldn't fall all the way thru.
Last edited by GPKiwi; 10-10-2006 at 02:58 PM.
10-11-2006, 06:10 PM #9
Went out today, full tank of gas as I thought I would be out for a while...but weather turned nasty and rain set in so I called it a day.
Got some runs, with 62.6 on the first sprint with trim set in neutral and dropped one washer off the ride plate, next run was trim down one (bow up 1) and got 63.3... I am stoaked with that and still not the best of conditions. Had trim set on down 2 but just could not stop the bull from bucking...damn thing!! That was a half superman with one leg still in the footwell.
64 has been my goal, but wonder with perfect conditions and hull all sealed etc that 66 may be knocking at the door?
10-11-2006, 08:25 PM #10
What is the temp in New Zealand this time of year? You will gain more with better weather. I believe the stock rev limiter kicks in at 7050-7100. You are knocking on that door right now. With your current motor mods you definetly have the best impeller, but with you running so close to the rev limiter you can't gain much more speed. If you fill the bolt holes in you should gain 1mph.
There are three mods I am considering. One is doing away with the siphon tube and installing a bilge pump, the other is blocking off the pisser, and the final mod is experimenting with the Wet Wolf AAT cone. Do you have any solid back to back numbers with the cone? It will be next spring before I do any of these. If you come up with a good location for the bilge pump let me know.
Congrats and keep up the good work.
Last edited by 97GPSLEEPER; 10-11-2006 at 08:30 PM.
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