Thread: 1200 upgrade questions?
12-19-2006, 08:44 PM #1
- Join Date
- Jul 2006
- grand bend.
1200 upgrade questions?
I'm a long time reader and I have a few questions regarding upgrades that I'm doing over the winter.
My current mods under the seat consist of
& riva d plate.
I will be adding
r&d power plenum,
milled stock head(150psi),
protec reed stuffers
& rejet carbs.
My first question is regarding the carb jetting. I have researched the correct jetting with choke plates and acc. pump disabled is 110 pilot, 120 main, 95g spring & 1.5n/s & adjust the #3 high thandle a 1/4 - 1/2 turn out more. I have also seen that some folks increase the main jet size on #3 to 122.5 or 125. Should I stagger #3 to 122.5, 125 or just go a 1/4 - 1/2 turn out more on #3? I realize that using a 120 main and turning the handle out more accomplishes the same thing so am I struggling with semantics here? Is removing the choke plates a waste of time? My boat doesn't start too easily cold(30-60 secs.) so I will be adding a primer. Where's a good place to buy the jetting & primer kit?
Do you think I will have enough power to spin a nujet 13/21?
I have modest expectations and hope to hit 70mph with this stuff...
Thanks for the Input.
Last edited by thebert; 12-19-2006 at 08:49 PM.
12-19-2006, 08:58 PM #2
What are you plan to do with your ski mainly, race or just rec riding ?
Carl at Long Island racing sells the rejet kits with T-handles.
This task can be done by yourself if you are mechanically inclined.
If the stock carbs have never been off the boat, they will need to have the "tamper caps" removed in order for the t-handles to be replaced.
A primer kit is a good idea. You can purchase those from places like Parker Yamaha, Ebay, ect....It helps from dry cranking your engine for quicker startup. Removing the choke plates help improve air flow.
If possible, try to get the PROK flame arrestors. They flow better.
70 is not a problem for a GP1200R.
If you keep your current pump, I would suggest a Solas 14/20 depitched to a 13/19 in order to keep your RPM's up.
I also recommend the V-Force III reeds. They give you roughly 80-100+ RPM's.
With the extra RPM increase and if you plan to upgrade to the 05 pump assembly, this will give you another 1.5-2mph depending upon the setup. Use a box stock dyna-fly if you get the VF3 reeds.
Also, ditch that stock intake grate. They are dangerous.
Get and R&D or RIVA 2 bar GP1200R grate.
If you buy the R&D or RIVA 800R intake grate, it will yield 1 more mph over the 1200 grate, but will not have the holeshot as the 1200 grate.
Also get an aftermarket rideplate such as an R&D or RIVA 1200 rideplate for better handling and more speed over the OEM plate. The OEM plate is great for rough water.
The jetworks mod really improves your holeshot !
Also, get an aftermarket digital tach to keep track of your motor's condition as you tune and modify the motor. PET-2100 is a grerat tach.
Invest in a good compression guage so you can get a baseline of your motor and keep track of its health.
Last edited by RX951; 12-20-2006 at 04:50 AM.
12-20-2006, 09:13 AM #3
I agree with RX951, he would never steer you wrong and has years
of experience with the 1200. With the help of Billie and a few others
(WFO, Fercho, Spud) my unported 1200 now runs 75 in the summer
with a blistering holeshot!
Also do a search for pump shoe sealing and reinforcing the pump
tunnel. If the shoe is not set correctly in the pocket you will never
get good speed no matter what you do.
12-20-2006, 07:42 PM #4
- Join Date
- Jul 2006
- grand bend.
Thanks for the replys.
I use the ski for rec. use only. I only have time to ride approx. 25-30 hours a season. I have already purchased the parts afore mentioned minus the carb jetting. I'm on a budget as I'm modding two ski's(wife's xpl) and mine with similar mods(head, flame arrestor, impeller & carb jetting) so I need to be thrifty. I have researched the carb rebuild, rejet & tamper cap removal and it appears quite easy as I have turned a few wrenches before. I have already reinforced the pump tunnel and sealed the shoe correctly. The 13/19 solas, riva intake grate & riva 1200 ride plate that I sanded to a smooth finish & shimmed to approx. 5 degrees has gotten me to 67mph. I also installed the jetworks valve via the fercho instructions to get a great holeshot. I made my own aluminum gasket for the water blockoff on the stinger. I definately need to get a tach after this round of changes. Perhaps next winter I will upgrade to the 05 pump...
Happy Holidays to all.
12-21-2006, 08:49 AM #5
Also, becareful by just adding shims to the front of the rideplate to obtain your "angle".
To acheive the correct angle, there is soem grinding that needs to be done to the bottom of the pump stator and rideplate bosses.
By just adding washers/shims, you can cause your rideplate to hang down on the sides where it meets the pump shoe.
From past experience, I have seen how .010 - .030 of material hanging down can cause "drag" losses in speed from 2-3mph !!
Also, if you are on a budget, ask on the forum or go on ebay, find a solas concorde 14/20. Have it depitched to a 13/19. this depitching allow you to keep the RPM's up in the 7200 range the 1200's like. Also, the 14/20 has a different root angle and hub vs. the 13/19 based prop.
* The 14/20 Processes more water.
* If you buy a 14/20, I will pitch it for you for FREE ! Just cover the Shipping to/from.
I was able to get 72+ mph out of the 14/20 Concord before I switched to the 05 pump.
With a 13/19 I was only able to get 69.6
Between all this experience on the Forum, using the search feature and browsing the How-To section, you can find lots of information. It doen't take alot of mods to just hit 70, but there is alot of "proper setup" like Duke Mentioned in order to allow what you have to work together.
I'd like to see more 1200R's on this forum run 72+ or mORe!
Seems today, everyone is 1300cc or biGGer ! These 1200's have so much potential. Ask Spud, H204You & Duke
And again, I highly recommend the VF3 Reeds. Thats one of the best bang for the buck mods you can buy.
Also, on the stock carbs, its been proven that there are plenty. There are some boats on the this forum running 80+ mph on "stock carbs"
* We have many carb afficianados on carb jetting and tuning....Spud, Hopatcong, Fullboogie, Fernando to mention a few.....
Here is the conversion parts list also if/when you decide.
Keep the 1200's ALIVE !
Last edited by RX951; 12-21-2006 at 09:13 AM.
12-21-2006, 08:57 AM #6
I think there is one on ebay already pitched to 13-19 by
Island Racing. Will try to find link.
12-21-2006, 09:29 PM #7
- Join Date
- Jul 2006
- grand bend.
Thanks for the heads up on the rideplate.
I have done a lot of research on this forum & the riva board over the past year. I have probably read 1000+ posts Yes, I grinded the bosses & pump stator down to fit the plate. Testing my modded riva plate vs. the stock plate, I'm getting approx. 3.5 mph gps on glass. I got the
used 13/21 nu-jet (THEBERT) from Jim(Thank You again) and want to use it.
I believe this is a nujet 6.5 setback? Should it be repitched to 13/19? I have read good things about this impeller for midrange & topend. Have you repitched a nujet? I have read that I need to install a plastic liner to use this impeller? I'm not quite sure on how to get the steel liner out and the plastic liner in? I still can't decide whether I should use 125 mains without choke plates or 120 mains with choke plates on the carbs. Somebody please decide for me.
12-21-2006, 09:38 PM #8
Hello Terry, You are correct it is a 6.5 setback. If you remove the chock plate you will need to run a primer kit and the 125 mains will work fine.
12-21-2006, 10:19 PM #9
03-16-2007, 09:04 PM #10
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