Re-jet/tuning R&D 3.5" Pro-Lock filters for 1997XP?

[KevinLamb]

Spent the day searching Forums, FB Forums, Google, etc. for info on whether I need to change jets/carb settings on a 1997 XP (787 engine) when I put on the R&D 3.5" Pro-Lock flame arrestors. Can't find the suggested carb tunings. My uninformed opinion tells me that the R&D's don't funnel as much air into the carbs like the Prok's do. So I am thinking maybe no carb adjustments needs to be done and I can just go with my current Factory settings. Betting I am wrong. Betting I might need to increase the size of the jets or maybe turn a screw out on the carbs to let more fuel in. Again, I can't find any info on what to do once the R&D's are on - the info is not even available on the R&D website. Has anyone who has put these on the 787 motor know if I need to pull the carb out of the boat and make changes?

 

[snikwad003]

You will have to make some adjustments, the stock air box has more restriction than the f/a so it messes with the metering. Make sure your tray seal and everything thing else that let's water in on the 97 is good because the f/a doesn't keep the water out of the motor like the aorbox does.

 

[Matt Braley]

You can try to turn the low speed needles out before you need to tear into the carbs. If the ski has a new bog when you hit the throttle then you can try turning the low speed needles out up to just over 2 turns out from closed. After that it makes no tuning difference and they may vibrate out.

The low speed needles are the ones closest to the base of each carb that have the "T" on the ends. If that does not work then you have to install higher low speed jets or lower the pop off pressure of the needle and seat.

 

[KevinLamb]

You will have to make some adjustments, the stock air box has more restriction than the f/a so it messes with the metering. Make sure your tray seal and everything thing else that let's water in on the 97 is good because the f/a doesn't keep the water out of the motor like the aorbox does.

Thanks - it is the exact adjustments I am trying to find - the biggest being whether I need to physically replace the jets to let more fuel in - that is a bigger job that turning the screws on the carbs - a much bigger job that I have never done before. Regarding water getting in - my boat has been really good about that so far - I do not get much in even when I ride fairly aggressively though when summer comes and I am out of a full wet suit I will ride harder and probably get a lot wetter. What little I can find about the R&D's says that the meshing is water resistant - but that is the dream marketing statement. Since my boat does not have the 951 engine (heavy) and I only weigh 138 lbs. the nose of my 97XP stays out of the water pretty well. If I start to have a problem I can restrict those giant holes in the boat hood. Last resort - those old red bilge pumps we used to run in the late 90's.

 

[KevinLamb]

You can try to turn the low speed needles out before you need to tear into the carbs. If the ski has a new bog when you hit the throttle then you can try turning the low speed needles out up to just over 2 turns out from closed. After that it makes no tuning difference and they may vibrate out.

The low speed needles are the ones closest to the base of each carb that have the "T" on the ends. If that does not work then you have to install higher low speed jets or lower the pop off pressure of the needle and seat.

Thanks, Matt - this is the kind info I was looking for. I will start with what you have suggested. The carbs were recently cleaned and the grey Tempo fuel lines have been replaced so any bogging or change in how it operates should come from the new filters. Should it come to the point that the best course of action is to do one or two the "inside carb" mods you suggest I will maybe trying going one jet size up first - this sounds a little simpler (for me) than trying to change pop-off pressure.

 

[KevinLamb]

I just talked to R&D. They said to NOT put their filter on the 97XP. Said because of the accelerator pump the carbs flood with their 3.5"'s. They said I would have to disconnect the accelerator pump to use them.Said they will work on my 96XP but the pilot jet has to go to an 80. Kinda sucks because I was not planning on doing anything with the 96XP and I have already ordered the R&D's. Guess I will keep the 96 and put the new Solas Concord 15/23 on the 96 instead of the 97.

 

[Matt Braley]

Yeah everybody needs a 96XP around. You would miss that if you let it go.

 

[mikidymac]

My 1997 XP had a Group K sleeper kit on it and he required the R&D Power Plenum and it ran great with the accelerator pumps. But if the manufacturer says not to use it I guess that's it.
Also on a stock ski you will see no performance as the stock airbox provides all the air it can use. And it is much more water resistant.

 

[KevinLamb]

Yeah everybody needs a 96XP around. You would miss that if you let it go.

I think that even if I get a 2019 RXPX-300 next season I will keep the 96XP - just as you suggest. The PX-300 will be the couch I drive at 75mph and the 96XP will be the air boat/fun boat. X4 hull in chop is the craziest ride Sea Doo ever made.

 

[KevinLamb]

My 1997 XP had a Group K sleeper kit on it and he required the R&D Power Plenum and it ran great with the accelerator pumps. But if the manufacturer says not to use it I guess that's it.
Also on a stock ski you will see no performance as the stock airbox provides all the air it can use. And it is much more water resistant.

Well, Mikidymac, I guess I just screwed myself. The factory says not to use it on the 97 and you say it is of no use on a stock boat. Guess I will sell the R&D here or on the 2-stroke parts Forum. what would I have to do to get a benefit from the R&D flame arrestors on a stock boat? I am guessing new head/domes?

 

[mikidymac]

Aftermarket pipe. More air and fuel out equals more in.

 

[KevinLamb]

Aftermarket pipe. More air and fuel out equals more in.

There are still some Factory Spec2's floating around out there...some Rossier's too. I guess I either sell the R&D or step up and spend more money. Let me ask this - I am told: "Your boat will run like shit if you run it with the stock air box off. The pop off pressure is to high! Those stock filters are really restrictive and run a 115 gram spring. if you take it off you will not pull enough vacuum through the carbs to send fuel through the motor. if you take it off you will not pull enough vacuum through the carbs to send fuel through the motor."
So, looks like, just to run the filters I have to re-jet, re-spring, re-do pop-off pressure, and put in a pipe! I think I have hit the point where it's costing too put into an old boat. I think I will put a Solas Concord 15/38 on it and be done. Anybody want to buy a pair of never used R&D 3.5" filters?! They should be here any day!

 

[mikidymac]

You hear correct. No reason to mess with a stock seadoo. The factory did an amazing job on getting all the power they could out of these engines. Short of adding a pipe there is almost nothing to be gained. Even the stock impellers are hard to beat.

 

[KevinLamb]

Thanks M., I am not going to mess with it anymore. I will either put the R&D's on a shelf for possible use if I get a pipe or I will sell it the day it arrives.
I did get an impeller that is an improvement for the 97XP - tested it and it performs well. Got the Solas Concord 15/23. Because the 97XP struggles more to come out of the hole than the XPL's that followed I find the Solas give me a really nice push to help me come back to speed from a sharp turn. Solas also says this impeller will give 1-2mph extra on the top end too but I am not counting on that to be true. And if I do get a pipe I will also have to re-do the carbs so I will just take it to Chris at Watercraft Magic because he will know what to do with the package.