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  1. #1

    SC Washers, Low RPM Starboard?


    I just bought '05 Speedster 200 with the 370hp SC engines. I've been reading my butt off trying to learn everything I can about these bad boys, and the ceramin washer thing has we quite worried.

    Anyways, I am only pulling 6,500 rpm off the starboard engine (according to tach, but who knows how accurate it is), and 7,200 on port as WOT. It seems like it wants to push right (have to hold steering straight with a fair amount of grip or wheel will pull to the right).

    I did notice when working on something the starboard throttle cable has been adjusted or worked itself loose, because the locktite bead is broken (port cable is intact). I'm hoping this is the case, and not a SC problem.

    I'm going to check it tonight, but in the interim, I wanted to see if anyone could enlighten me on a couple things.

    First, what washers (link?) are the ones I need to buy for my 185hp SC/a side motors?

    Second, I have worked on performance engines for ATVs for quite a while as a hobby (rebuilts, porting, polishing, milling heads, etc), but I adminitantly have no experience working with any type of blowers, in any capacity. Is this a job that is better left to those with direct experience, or is it a pretty simple procedure for those machanically inclined with a equipped garage? If the latter, can anyone recommend a good AZ based mechanic (I saw they can be shipped out, but I have a couple things I want looked at/worked on as well).

    Third, I saw someone mention a thread in the PWC forum since they are the same engine, but I think that was for the intercooled version? Can someone direct me to the proper thread and rebuild for these specific engines' SCs, if one exists?

    Thanks, and awesome forum!

  2. #2
    Took the intake off the SC and the impeller does not spin. It has just a tad, maybe a almost millimeter of slop when I tried to spin it either way, just enough to make a little clicking. I suppose this is normal.

    So, anyone know how to properly adjust the throttle cable. Usually the body has a notch or something to line up against for full throttle, so the two cables can be sync'd but I don't see anything like it. Or, is it more or a trial and error things once it is in the water?

    I'm also starting to wonder if I don't have a fuel or air delivery issue? Hrmm, so much to troubleshoot.


  3. #3
    Dr Len's Avatar
    Join Date
    Jan 2006
    New Jersey Attitude Capital of the World
    I think it would be a good idea to rebuild both chargers. You do have ceramics in there.And they could go at any time. Then you will be in a world of sh_t. Pull out the charger your having problems with. That the real way to see if there is any problems.

    Read this thread it has alot of good info

    Then you can get everything you need from Jerrys store

  4. #4
    Senior Member watermedic's Avatar
    Join Date
    Apr 2005
    West Virginia
    I agree with Dr. Len. Pull the chargers and get the ceramics out. That's one thing you won't have to worry about. While the SC's are getting rebuilt you can get the throttle cable problems resolved and be good to go.

  5. #5
    Thanks for the feedback. When you say rebuilt, do you mean a full rebuild, or just the washer replacement?

  6. #6
    cyoungesq's Avatar
    Join Date
    Apr 2006
    Bridgeport, CT
    Quote Originally Posted by beezer View Post

    I just bought '05 Speedster 200 with the 370hp SC engines. I've been reading my butt off trying to learn everything I can about these bad boys, and the ceramin washer thing has we quite worried.

    Anyways, I am only pulling 6,500 rpm off the starboard engine (according to tach, but who knows how accurate it is), and 7,200 on port as WOT.
    You have a Supercharged '05 370 hp speedster?! I thought they didn't come out with those until '06, and, 370 hp is the naturally aspirated motors' output, and, 7200 is awfully low for a supercharged engine, let alone 6500.

    You sure you have superchargers?

  7. #7
    lol, yes, I can see the chargers with my own eyes and like I said, inspected the impeller.

    In '05 they were SC, without the IC. They had 155hp X 2 (NA) and 185hp X 2 (SC) available.

    According to the specs it is rated 185hp @ 7,500 RPM. I have seen it flutter up to 8k or so under cavitation =(

  8. #8
    cyoungesq's Avatar
    Join Date
    Apr 2006
    Bridgeport, CT
    Ah, I the grasshopper now see the wisdom in your reply.

    Over time, my cables streched and got slack in them ... an ajustment of the cable with the nut near the throttle body took up the slack and cured the resulting slight drop in rpms.

    I did it with the throttles in idle - all the way back - and then taking up all slack so that in idle there was virtually no slack in the cables.

    I have since heard that there is a theory that if the cables are overtightened, the butterfly valve in the throttle body could open too far and cause a slight reduction in flow (like overextending). I have not perceived any loss in performance having done it the way described and both throttles are in synch very well.

    Sorry about my model ignorance and suggesting yours!

  9. #9
    Jeepster's Avatar
    Join Date
    Jul 2007
    Quebec, Canada
    Get those throttle cables sync and adjusted well first.

    The definitely remove the 2 supercharger and (at least) do put in some metal washers in, i think on the older 185HP they were already in metal, but were titanium coated and prone to slip, i'd discuss the clutch washer with Greenhulk prior to buy anything, he is the man and will let you know what you should be aware of (providing you at least buy your parts from him in a manner to thank him back...!)

    I think your problem is caused by 2 issues, throttle cables more than anything, but as you know if you do not take care of the superchargers could cost you total afterward...

    By the way, how many hours you got on them...? Close-to or past 100 hours mark, and i would recommend total ground up rebuild of the supercharger, and while you do it, they will be rebuilded to latests specs/model years parts.

    Good luck.

  10. #10
    I went out today with my GPS. I managed a meager 50mph top speed (2 people totaling 320 pounds, maybe 100 pounds total gear/supplies on board, 1/2 tank when tested). This seems low because the manufacture claims over 55 (and manf. numbers are always understated in my experience to ensure ALL the products will do a minimum of the stated claims), and others have said they have had GPS verified 60 - 65mph stock. The owner claimed he got 70mph with one person in the very same boat the first season (likely exaggeration, but you can't confuse 50mph with 70mph on water). The boat only had 25 hours on it (now 30), and you can tell by the looks it was only used a few times. This boat was only used for special local outtings once in a while as they had/have a 40 yacht in Cali for weekend get aways).

    I adjusted the cables and still only 6,500 rpm on starboard at WOT, about 7,100 RPM on port. When it cavitates (end of a 360 if I don't pull the throttle back just at the right time), it gets much higher on both.

    So, I'm at a loss as to what to do in terms of troubleshooting it. I figure there could be up to a dozen or more different things to go through. Anyone have any ideas on the most obvious/easy things to inspect to cross off the list first? Does the service manual include troubleshooting procedures and such?

    FYI, the boat had been sitting for without use for about 6 months (according to owner, Upon reflection, the gas could be older as he used it about once every 3 months on average, argg). I didn't drain the tank, figuring I could dilute it, but didn't realize there was more old (doesn't smell like stale/bad gas though) than I had thought based on the gauge until the gas pump told me I was full. I now had 40 gallons of fuel (25 of it old), I had no idea how to safely and responsibly dispose of, so just decided to burn it. I have since topped it off with another 20 since then with no performance change. My cals suggest I would have a max of 30% "old gas" content, and this time out. Now I am thinking about siphoning out the bottom 5 gallons in case there was any separation.
    Last edited by beezer; 04-14-2008 at 02:21 AM.

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