Results 1 to 7 of 7
  1. #1

    Figuring Out this Pro 785

    I'm a lifelong diehard 2-stroke Seadoo performance guy but I've always been tempted by the Pros so when a 785 and a 1200 came up for sale on a clean double I pulled the trigger. The guy thought he had all the issues worked out but the 785 does not seem as impressive as it should especially since there are some mods. I would love some insight from you guys, been lurking over here for years.

    Mine is a 97 with a 2000 engine. I don't know what the stock pumps looked like but this seems like an aftermarket 6 vane to me. There is a wedge between the pump and nozzles as well. Can anyone identify it?

    I recognize the Red Top(True CAD) 44mm carbs. I am very familiar with these and other annular discharge carbs from my Doo tuning. These seem to be in great shape but I have no idea where pop off and jetting are at. They are sitting on what appears to be an aftermarket mani and I see V-force reeds.

    Compression from front to back is 130, 136, 140. The holeshot is not that impressive and it's only turning 7050 rpm so I think the impeller has too much pitch. The steering has slop and it appears to be inside the cable. I can tell it had an aftermarket head because it has the 3 bypass fittings on the rear right under the seat. There are no decals on the ski so I'd like to do something there too.

    I want to get this thing right. Thanks for reading and any knowledge or suggestions you might have.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	IMG_0350.jpg 
Views:	38 
Size:	88.2 KB 
ID:	452732   Click image for larger version. 

Name:	IMG_0349.jpg 
Views:	28 
Size:	88.6 KB 
ID:	452733  

  2. #2

    Join Date
    Aug 2007
    Location
    Wisconsin
    Posts
    178
    +1
    2
    Impeller should be 12/17 skat track. Can't really tell what you have from the pics. You can pull the pump and look at the number on the side of the impeller and we can figure it out.

    Ok hitting 7050 is a not healthy pro. When the pipes hit it should hit hard. I am a pretty strong guy and after an hour of riding a pro I struggle to open up hands all the way from holding on so tight.

    What do the plugs and wash look like? You will know when it is running right.

  3. #3
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
    Join Date
    Oct 2006
    Location
    Cleveland OH
    Posts
    17,634
    +1
    55
    Welcome.

    The SS 6 vane pump is very common. Nothing unusual there.

    All Polaris pumps use a wedge between the pump and exit nozzle. Make sure it's installed correctly though. Thin part at the top and thick on the bottom. Factory wedge was 4* but they were made ranging from 2* all the way up to an 8*. 2 would provide the least amount of bow lift (best rough water) with an 8 providing the most. (best for flat water)

    Some people love the red top carbs, and some do not. I personally have a set on mine.

    Can't tell from the pic, but what makes you think the intake manifold is aftermarket?

    If you suspect the head has been replaced, that might be why the carbs aren't responding well. Prob had high compression heads before and went back to stock without adjusting jets is my guess.

    You'll need to get a look at the piston wash and see what the pistons are telling you as far as jetting goes.

    A couple things that might be causing you issues may be 1. the exhaust valves and 2. the triple pipes

    1. First, a common mistake others make is installing the exhaust valves up-side down. They will go in and not perform correctly like this. They also run off an electric motor that is controlled by the CDI and utilize cables for movement. So make sure the cables are adjusted properly on all 3 and that they are moving when engine RPM increases around 4k RPM.

    2. The pipes are aluminum and do sometimes crack. When this happens, your performance goes out the window. A pressure test of the pipes will let you know if they are damaged.

    There is a lot of info in the "tech" section if you take the time to look around. Here is a quick link to show the preferred method of triple pipe cooling using a single jet works valve.

    http://greenhulk.net/forums/showthread.php?t=19308


  4. #4
    Great stuff thank you. The intake mani might be stock I'm just not used to the parts yet. That pump is very impressive, it would be a very costly upgrade on a Seadoo. Someone has done the Jetworks upgrade to mine so that's good. I'll look into those other things and see what I find.

    I used to race and one year a 785 passed me up all 3 heats. I'm looking forward to getting it right.

  5. #5
    casey67's Avatar
    Join Date
    Sep 2006
    Location
    Lemont,IL
    Posts
    3,113
    +1
    65
    It might just be the picture, but is the pump exit nozzle opened up? Should be a cast-powder coated smooth piece.

  6. #6
    Connecticut CrazyA's Avatar
    Join Date
    Nov 2005
    Location
    CT.
    Posts
    8,266
    +1
    1,107
    Definitely make sure everything is right and that it’s not gonna burn down on you and then like Xlint said, make sure that your exhaust valves are in properly and opening all the way. Just like the motors that you’re used to with the RAVE valves, you know it will never reach top RPM if they’re not opening up all the way. These guys will definitely get you squared away!!!


  7. #7
    rpa101's Avatar
    Join Date
    Mar 2014
    Location
    kingston ont canada
    Posts
    1,229
    +1
    70
    When my pro only turns 6800/7000 it’s always been a power valve problem
    when it turns 7500 max it’s been a cracked pipe or head pipe leaking water in to the exhaust
    these are a funny ski all you need is a tach/and a gps to tell if there’s something going on

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Selling polaris pro 1200 and pro 785 2001 and 2000
    By polaris pro 1200 mods in forum Polaris PWC Performance
    Replies: 1
    Last Post: 07-18-2013, 09:33 PM
  2. WTB - Parts looking for a factory polaris cover for my 97 pro 785 and 2001 pro 1200
    By 1998PRO785HO in forum Polaris Classifieds
    Replies: 0
    Last Post: 04-23-2012, 01:53 AM
  3. To buy a Pro 785, or not to buy a Pro 785...that is the question.
    By sn-95 in forum Polaris Open Discussion
    Replies: 38
    Last Post: 06-26-2011, 12:51 PM
  4. 785 PRO..--Asking for CDI Polaris 785 Pro, 2000
    By deba-os in forum Polaris Open Discussion
    Replies: 0
    Last Post: 08-28-2010, 01:49 AM
  5. Replies: 1
    Last Post: 10-15-2007, 01:42 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •