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  1. #1

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    1998 exciter engine mods

    i have a 1998 exciter with twin 1200's. 1 eng is blown so i'm going to rebuild them both. my question is this. what's the best way to get a little more horsepower from them. are there any decent aftermarket exhaust systems for these engines. i also want to rework the heads, remove the choke shafts and install aftermarket flame arresters. who and what does everyone recommend? any suggestions are very welcome. thanks


  2. #2
    krispaintballz's Avatar
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    Quote Originally Posted by burdmark View Post
    i have a 1998 exciter with twin 1200's. 1 eng is blown so i'm going to rebuild them both. my question is this. what's the best way to get a little more horsepower from them. are there any decent aftermarket exhaust systems for these engines. i also want to rework the heads, remove the choke shafts and install aftermarket flame arresters. who and what does everyone recommend? any suggestions are very welcome. thanks

    Its going to be hard!!!!! Well throw the whole exhaust out the window. Trying to even find one set of pipes yet not cracked or abused is a miracle, two sets noway. Also parts are really hard to come by. What i would do is to weld and balance the crank do some mild porting, get a girdled head with 150 to 170 psi, big bore kit, riva cdi unit (if you can find them), and that would be about it for now. Oh get some new carbs? at least F/A's with adapters. But thats about it. Its a lot though and your going to be on the endge of do i stick with these or go with pv's. If it was me i would stick with non pv engines cause i think non pv engines are a bit stronger. pv like to break a lot.

  3. #3
    I am not trying to make any sort of argument hear from the last poster so pleaase dont take it that way, just writing from expierence!!!
    I would stay clear from porting and a big bore kit on this thing!!!!
    Its way to much money and for the gains wouldnt be that great and woud require a tremendous amnount of tuning on your part! As for the girleded kit and the true and welding of the crank, the girlded kit is only need for Really highout put engines so not required here, and same goes for the true and wedling of the crank! Also just to get to the crank requires tear down of the whole engine and unless you are truly expierenced with putting case halves back togther pressure testing and buying a whole new gasket set and bearing seals for the whole entire engine, not worht the investment.
    Here is where I would start where you would spend the least amount of moeny with the most amount of gains.
    You can take your OEM head and have it shave down for more psi which will give you more punch and maybe a slight increase in RPM.
    Have the carbs rebuilt and rejetted with flame arrestors attached
    V force reeds and stuffers
    Maybe a timing key but not really warranted.
    then concentrate on the prop setup.
    Stay away from the other huge mods, trust me reliabilty will go way down the the gains will not be that high. If you do these mild mods on a boat that has 2 engines you will have a noticable difference, and reliabilty will still be there and you wont break that bank that badly as well
    The carbs can be rebuilt by Carl at Island Racing phone number below and he can supply all the parts as mentioned and FYI Carl is the foremost best expierenced guy on this forum when it comes to the jetboat circuit!!!
    516-883-0090

  4. #4

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    Have a look at:

    www.yamahajetboaters.com

  5. #5
    krispaintballz's Avatar
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    Quote Originally Posted by scittb View Post
    I am not trying to make any sort of argument hear from the last poster so pleaase dont take it that way, just writing from expierence!!!
    I would stay clear from porting and a big bore kit on this thing!!!!
    Its way to much money and for the gains wouldnt be that great and woud require a tremendous amnount of tuning on your part! As for the girleded kit and the true and welding of the crank, the girlded kit is only need for Really highout put engines so not required here, and same goes for the true and wedling of the crank! Also just to get to the crank requires tear down of the whole engine and unless you are truly expierenced with putting case halves back togther pressure testing and buying a whole new gasket set and bearing seals for the whole entire engine, not worht the investment.
    Here is where I would start where you would spend the least amount of moeny with the most amount of gains.
    You can take your OEM head and have it shave down for more psi which will give you more punch and maybe a slight increase in RPM.
    Have the carbs rebuilt and rejetted with flame arrestors attached
    V force reeds and stuffers
    Maybe a timing key but not really warranted.
    then concentrate on the prop setup.
    Stay away from the other huge mods, trust me reliabilty will go way down the the gains will not be that high. If you do these mild mods on a boat that has 2 engines you will have a noticable difference, and reliabilty will still be there and you wont break that bank that badly as well
    The carbs can be rebuilt by Carl at Island Racing phone number below and he can supply all the parts as mentioned and FYI Carl is the foremost best expierenced guy on this forum when it comes to the jetboat circuit!!!
    516-883-0090


    Its ok, he already mentioned the pipes so i thought he was going all out. About the girdled head though, I feel you should always use a girdled head because it transfers the strength throughout the whole cylinder. I also metioned the welded crank and prting because he was talking pipes(tripples?). So i would think he was going to run 7400 to 7800 rpms, with that many i would weld and balance the crank, also porting cause you prob want to heighten the exhaust ports and then that would lower compression. And dont forget CDI. Thus get the girdled head with removable domes. With all this I would then get some new carbs and f/a. Parts are not made new anymore so thinking he would buy parts from other people(used) he would not be spending a fortune. I am not arguing i just know i have a setup like that and as long as you run lower psi and good gas it really runs itself. Yes you are right i do tune a lot. It is not a ski i just jump on and go!

  6. #6
    I wasnt thinking you were arguing by any means, I just mentioned that myself becasue thats how the arguments usually start here. All valid points in your last comment!

  7. #7
    krispaintballz's Avatar
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    Quote Originally Posted by scittb View Post
    I wasnt thinking you were arguing by any means, I just mentioned that myself becasue thats how the arguments usually start here. All valid points in your last comment!

    hey its ok i am not the arguing type. I would rather come over and help you with your ski than argue. You do make good valid points too. The way you mentioned does save a lot of money while giving you really good gains. What i mention would probably be for a person who has no limit in what he wants to do to his/her ski/boat. With both of us giving him a direction in both ways helps him out the best. thanks

  8. #8

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    Sep 2007
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    Mill the heads to 91 octane and get Solas props for starters. About 3mph gain and pulls much harder. This is good info http://www.groupk.com/yjetboat.htm

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