Krispy
Well-Known Member
The trim tabs are well worth the reduced porpoising I see in rough water. I weigh 165# Ambient temp was mid 90's engine has 220 hours (!) on the original bore size, still has 147#'s compression.
96 XP Top Speed
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The trim tabs are well worth the reduced porpoising I see in rough water. I weigh 165# Ambient temp was mid 90's engine has 220 hours (!) on the original bore size, still has 147#'s compression.
spx800
Active Member
I don't have a gps, but my spx stayed ahead of my rx all day on smooth water (77 deg. F). The speedo on the rx was saying 60mph turning 6900 rpm. The compression on the spx when i checked it in the spring was 155/155 on a stock motor. All new fuel system (carbs, lines, filters etc.), new oil filter, counter balance oil yada yada. It has a prop, nozzle, intake grate and a different pump, but nothing major. My buddy and i are roughly the same weight, around 190 lbs.
scrisp
Active Member
My 58 mph run was with me (240 pounds lol), and a set of R&D tabs (0°) I think, and an R&D grate. It was about 76° that day, with no wind at all. I need to get a TinyTach installed, as I'm not sure of the RPM. I haven't checked compression since I first got the motor running (about 10 hours ago) and they were somewhere right around 162 each. Someone said that they will settle in a bit lower wfter the breakin period, which just ended.
I'm still running the plugs that I used for the breakin, and my RAVES are leaking a bit. So, I have a bit of maintenance to do. Two guys were running Yamaha Tigersharks, and both asked me how fast I went, when I got the dock. They seemed impressed. lol
I'm still running the plugs that I used for the breakin, and my RAVES are leaking a bit. So, I have a bit of maintenance to do. Two guys were running Yamaha Tigersharks, and both asked me how fast I went, when I got the dock. They seemed impressed. lol
scrisp
Active Member
I have R&D tabs on mine, and it is way crazy with the porpoising. :-( They are the flat/straight 0° type, so I wondered why even both adding them? My SPX is way more well behaved than my XP. I have wondered if the VTS is not extending to its limits, it doesn't really seem to do much, but it definitely moves up/down.
scrisp
Active Member
I can feel bit of difference, when down it cuts through the chop a bit, and when up, up goes over the chop a bit. But my SPX, when the trim is down, it pushes the nose way down in the chop, and when it's up, it is as if just the grate is in the water.
The ski sat for a long time, and the girl that I bought it from said that the VTS didn't work at all. So, maybe there is some issue with it going the full travel that it should, or maybe those tabs in the rear make it handle differently. It does porpoise like crazy on just a little chop though.
purple_people_eater
New Member
you boys just wait... i'll show you the meaning of x4 speed here soon. if i don't kill myself in the process lol. :willy_nilly:
Krispy
Well-Known Member
When I added the nozzles to my setup it seemed to give my VTS more authority over the situation. I think it may be slightly longer than the stock nozzle so it has more "leverage" on the ski.
The thing that I think is the coolest, is that my mostly stock ski will hang with many of the new skis, even some forced induction models, especially out of the hole. And I have a fraction of the $ invested in my XP than others do in their trailer alone.
If it wasn't for the trim tabs I would have sold the ski, I rarely run with the trim all the way down except for launches (and then I trim full up) or when I am trying to do 360's, I find with the trim down (or mostly down) after I rotate that first 180 my pump stays hooked up somewhat so I can power through the next 180.
[MENTION=37676]purple_people_eater[/MENTION] what do you have cooking?
The thing that I think is the coolest, is that my mostly stock ski will hang with many of the new skis, even some forced induction models, especially out of the hole. And I have a fraction of the $ invested in my XP than others do in their trailer alone.
If it wasn't for the trim tabs I would have sold the ski, I rarely run with the trim all the way down except for launches (and then I trim full up) or when I am trying to do 360's, I find with the trim down (or mostly down) after I rotate that first 180 my pump stays hooked up somewhat so I can power through the next 180.
[MENTION=37676]purple_people_eater[/MENTION] what do you have cooking?
scrisp
Active Member
I don't standup on mine, so maybe that is where I'm a bit different. When I launch, it jumps up and out of the water and the grate unhooks and loses thrust. If I adjust the VTS down all the way, it will still do it, but does improve somewhat. If I trim it up, it beats me to to death even in the smallest chop. If the water is really smooth, I don't have any problem, but super smooth water is pretty much non-existent unless I go out there at 8am. lol On my SPX, if I'm trimmed all the way down, and at full throttle, then trim up, I can actually feel the increase in speed. The XP is way more fun though, so even with the beating that I take, I wouldn't trade it for nothin'. 
purple_people_eater
New Member
you'll all find out here soon. lets just say i've finally gotten the money and bought the parts to do something that i've wanted to do for years. i got my hands on some serous stuff, including a couple things few people have ever heard about, much less seen. its either gonna be one bad x4 or a complete death machine. even the guy i've gotten all the parts from and had a similar set up in his xpl that he raced says it'll be a scary ski.
I bet I've heard of those parts. I probably know of the guy that had them. Can't wait for your build and hit me up anytime for ideas and little odd performance parts.
Kallibrated
New Member
All I do is stand up on my XP. It just feels better. When I sit it seems to beat me up and hop out of the water. There is no way I could ride this machine sitting all the time especially where I ride. When I drag race I've found I get the best hole shot by standing and leaning far forward. My only gripe is my back gets sore (6'3") from hunching over.
purple_people_eater
New Member
i'm 6'2" and aftermarket handle bars fix that issue, also standing up, your knees are absorbing the shocks from the hull.
Krispy
Well-Known Member
Well start a thread already! This sounds sweet.
purple_people_eater
New Member
i'm getting to it bro lol my work load at the shop right now is insane. i'm actually turning away business. i'm pretty much resigned to the fact i'm not going to have it running and out this year. i'll start the thread here soon. i'm waiting on the last puzzle pieces to come in.
No you should be a little faster then that. How many rpms are you turning.
rj2
New Member
7030 - 7050 or so. maybe on glass it would be better? i sometimes have a problem with it porpoising when wide open so i have to lean either way a little bit to get the ski to stop bouncing but then its not running a straight line, not sure what run was 57.5. other max i have seen anywhere from 55.5 to 57.5...
what should my jets be? i think it might be underjetted. when i was looking for the carb filters to clean them and saw one of the main jets was 140 which i figured should be higher for pipe + prok's?
could it just be poor carb tuning too? i made changes to the adjusters when i had the carbs off for cleaning. i have more response and higher rpm now than before but have to give it a little gas for warm start and had issues 2x with cold starts where it took awhile to start. could those be fixed with carb adjusters?
what should my jets be? i think it might be underjetted. when i was looking for the carb filters to clean them and saw one of the main jets was 140 which i figured should be higher for pipe + prok's?
could it just be poor carb tuning too? i made changes to the adjusters when i had the carbs off for cleaning. i have more response and higher rpm now than before but have to give it a little gas for warm start and had issues 2x with cold starts where it took awhile to start. could those be fixed with carb adjusters?
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