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  1. #1
    raiderteen's Avatar
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    Old School Gurus - Pump Conversion Question

    Hey guys,

    Been a long time member due to ownership of a raider 1100 since 2005. Well I recently picked up a LS2000 jetboat equipped with twin 1200 Non-PV motors. I am in early planning stages of a 4 stroke conversion and have a pump question...

    The 1100/1200 pumps used the completely removable pump including the duct as opposed to the newer 1200PV and 4 strokes having the pump duct space glassed in and the rest of the pump bolting up. Also, the newer 4 strokes use a larger diameter driveshaft and larger couplers as well.

    I think I have four options listed in order of best to worst.

    1st: Modifying a newer 155mm stator to work with my existing pump setup. Which if I am correct would allow me to use the larger driveshafts seen on the 4 strokes due to the bearings being of the larger center diameter. The only issue here is if the larger driveshaft would fit through the driveshaft tube? I would obviously have to upgrade to the newer midshaft/intermediate bearing carrier as well.

    2nd: A custom or modified midshaft coupler allowing me to use my complete existing pump setup. My only worry here is strength of the smaller diameter driveshaft. But maybe it wont be a issue. This is a boat so I have to remember its not going to get thrashed on as much as jetskis do.

    3rd: A custom driveshaft or modified 4 stroke drive shaft that would allow me to thread the larger 4 stroke coupler in place while using my existing pump setup. This would be expensive potentially. And might not even work due to the bigger end for the coupler not fitting through the driveshaft tube.

    EDIT 4th: Retap the original motor couplers to fit the larger threads of the 4 stroke crankshafts. Allowing me to use all of the existing pump setup. I consider this the best option at this point. Thanks TimeBandit for the suggestion (from another thread)...sometimes the easiest options get ignored when overthinking things.

    Which option is most feasible? I know the stator can be converted to 2005 style. In theory I would use the stock 05 bearings for use with the larger driveshaft...if it would fit through the tube. Addicted has done this here but swapped the bearings to the 1100/1200 size bearings. http://greenhulk.net/forums/showthread.php?t=139120

    I wish I had a larger driveshaft laying around for mock up as I have one of the pumps removed from the boat currently for a impeller housing replacement...
    Last edited by raiderteen; 03-21-2019 at 10:06 AM.

  2. #2
    raiderteen's Avatar
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    Edited first post to add 4th option...

  3. #3
    Adam's Avatar
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    The problem you will find is the length of driveshafts on the newest skis are shorter than the 1100/1200 pumps . The 1100/1200 pumpshafts are smaller diameter too , you can fit the later pumps to the 1100/1200 pump shoe with the larger diameter driveshaft but you will need to a longer mid shaft to reach the newer shaft . Anything is possible with some thought and effort. You might as well use a 160mm pump if you are going to use the 1.8 SVHO engines to get the most from those more powerful motors .

  4. #4
    raiderteen's Avatar
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    I had another thread in the 4 stroke section discussing this conversion and inquiring about 4 stroke engine dimensions. The MR1 and 1.8L engines are simply too long to fit in my engine compartment. I have 31" MAYBE 32" with foam insulation removed from front bulkhead to rear bulkhead in my engine compartment.






    I have yet to get any detailed dimensions of the TR1 motors. Specifically with the front air box and electronics removed. That will be the only way that motor will fit (relocation of air box and E-Box) as total length as installed is longer than 31".

    Using the TR1, it would be very close to existing power output (slightly lower most likely). So option 4 would be the best bet if I had to guess. Just reuse existing pump setup and convert a 4 stroke coupler to thread onto the existing intermediate shaft.
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  5. #5
    Myself's Avatar
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    I had a customer with an LS2000 that ran great after I did pumps and carb mods.
    I have another customer with a twin engine Exciter that I need to tune in this spring.
    They really are strong when dialed in. Why try to reinvent the wheel? Just rebuild and lightly mod those 1200's.

  6. #6
    raiderteen's Avatar
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    After purchasing it back in March for a great price and bringing it back from the dead (blown motor, seized pump, electrical issues) I ran the boat all season long with zero complaints. It is a fantastic boat with plenty of space and still pretty quick for its size. I am beyond happy with it as is.

    But I think it would be a pretty cool project to do. It's pretty common in powersports and the auto world to want to be a little different. I am the same way with my vehicles. Its not every day you see a 1985 GMC Jimmy with the L98 TPI motor from a Vette or a 1986 Trans Am with a fully built 406ci fuel injected small block and TKO 600 5 speed. Sure I couldve done bolt ons to the factory motors in each vehicle. But I wanted more and had a goal to do it a little different instead of the typical "LSx swap it". Similar to anyone else on here who has converted to a different power plant from factory. Without that kind of mindset you would never have seen GPRXP swaps, MR1/SUV swaps, ect.

    Not to mention the improved fuel economy of a pair of TR1's over the oil and gas thirsty 1200's would be greatly welcomed.


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