glouis1723
New Member
i was wondering if i could add some mods on my 1997 gtx 787 to make the acceleration and top speed better? just got a new engine in it 0 hours still have to break it in. Thanks!
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Not much to do except maybe change out the impeller for a different degree. If you do you will either have better bottom end, or better top end...but not both.
Karl
Karl
you can install a open element spark arresstor but YOU WILL HAVE TO RE-JET THE CARBS!
THIS WILL ALSO MAKE IT EASIER TO GET WATER INTO INTAKE SYSTEM!
so if you like to wave jump and submarine or sir there and do donuts all day then maybe not a good choice, but this will WAKE UP the performance
try a different water box/muffler, again some fine tuning might be needed.
and this will increase the sound output of the ski, so watch out for THE MAN!
lastly, high compression head, but again carb work might be needed and the use of a race fuel and or a blend of pump gas and race gas might be needed.
this can also stress the engine and effect reliabilty.
with these mods you will make more power and be able to spin a more aggresive prop.
check with aftermarket suppliers for what they recomend as far as jetting and tuning specs, and do your homework
mud
THIS WILL ALSO MAKE IT EASIER TO GET WATER INTO INTAKE SYSTEM!
so if you like to wave jump and submarine or sir there and do donuts all day then maybe not a good choice, but this will WAKE UP the performance
try a different water box/muffler, again some fine tuning might be needed.
and this will increase the sound output of the ski, so watch out for THE MAN!
lastly, high compression head, but again carb work might be needed and the use of a race fuel and or a blend of pump gas and race gas might be needed.
this can also stress the engine and effect reliabilty.
with these mods you will make more power and be able to spin a more aggresive prop.
check with aftermarket suppliers for what they recomend as far as jetting and tuning specs, and do your homework
mud
Engine life?...
These kind of mods are those you might expect to see an experienced mechanic or racer do for better performance. The forum is made up mostly of novice mechanics or owners who are un-happy with getting ripped off every time they take their ski to the shop for an oil change.
In the last few years, 90% of the members I've worked with who are looking to gain an extra couple mph or just want a better hole shot, elect to make modifications to their pumps. You see a lot of impeller changes. The Skat Trak swirl impeller has been a popular mod. The more expensive pump extension is nice, increases speed because it lifts more hull from the surface of the water, less drag. The wedge is cheaper but isn't for all skis. Probably the most feasible is switching to a power nozzle and an impeller change.
The Rotax engine is already designed as a high performance engine; 2 strokes making over 7k rpm and 4 strokes over 8. Here in the forum, the majority of members are recreational. If you want to race a circuit or if you just have deep pockets and want to blow some bucks, then make the engine changes in the direction as was quoted above. But, remember, when you mod the engine, you cut the life span of the engine in half. Race engines or engines modified with changes to bore and stroke, changes in exhaust and jetting, create more power but also, create more heat and stress, which ages the motor 3 times as fast.
Unless your rich or wanting to race, I'd recommend you stay with pump mods to keep the wear on your new engine minimal. That way, you might make it last another 10 years.................:cheers:
These kind of mods are those you might expect to see an experienced mechanic or racer do for better performance. The forum is made up mostly of novice mechanics or owners who are un-happy with getting ripped off every time they take their ski to the shop for an oil change.
In the last few years, 90% of the members I've worked with who are looking to gain an extra couple mph or just want a better hole shot, elect to make modifications to their pumps. You see a lot of impeller changes. The Skat Trak swirl impeller has been a popular mod. The more expensive pump extension is nice, increases speed because it lifts more hull from the surface of the water, less drag. The wedge is cheaper but isn't for all skis. Probably the most feasible is switching to a power nozzle and an impeller change.
The Rotax engine is already designed as a high performance engine; 2 strokes making over 7k rpm and 4 strokes over 8. Here in the forum, the majority of members are recreational. If you want to race a circuit or if you just have deep pockets and want to blow some bucks, then make the engine changes in the direction as was quoted above. But, remember, when you mod the engine, you cut the life span of the engine in half. Race engines or engines modified with changes to bore and stroke, changes in exhaust and jetting, create more power but also, create more heat and stress, which ages the motor 3 times as fast.
Unless your rich or wanting to race, I'd recommend you stay with pump mods to keep the wear on your new engine minimal. That way, you might make it last another 10 years.................:cheers:
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why hide what can be done to this ski?
to say only a prop change is available is not correct
let the users of this forum decide what is and what is not right for them
and as i posted in line 8
THIS WILL STRESS MOTOR AND EFFECT RELIABILTY
787 motor is a sweet one to beef up a bit if done right
the key is doing it right, jetting the carbs is a must
horsepower aint cheep !! no one said it was
mud
to say only a prop change is available is not correct
let the users of this forum decide what is and what is not right for them
and as i posted in line 8
THIS WILL STRESS MOTOR AND EFFECT RELIABILTY
787 motor is a sweet one to beef up a bit if done right
the key is doing it right, jetting the carbs is a must
horsepower aint cheep !! no one said it was
mud
Hide?
Hide?.... I don't see where that is hiding something about this motor. I've made a statement that is straight to the point. I never said the only mod available was a pump mod. It seems, from interacting with our members over the past few years, that's their choice.
You've only been working this forum for how long?..... Well, ever since I've been here, working as a member then a mod, members want to make their motors last as long as possible, doing the work themselves, most as frugal as I, making their money stretch in a time the economy isn't friendly to putting into our toys.
They might have a manual, might not. A huge percentage of members who do have manuals post questions to me by thread or by PM, asking me to explain something in lamens terms because they dont' understand all the tech terms used in manuals. I'm' quite sure they don't understand your upgrades at all.
Our forum was built on and operates on members who do not race or have a lot of money to dump into an engine. That's not me guessing, that's a fact from reading and posting in this forum for over 2 years. Members who have been ripped off paying $3,000 bucks for a shop to put a new motor in their ski, just to have it blow up and then, the repair facility blame them for the failure (usually blaming their oil pump), is why people are here. They only want to fix or maybe, add a couple horsepower to their motor. (I added 5 mph to my GTX with an impeller change).
There might be a small percentage of members, who might want to use aftermarket mods on their motor but that does not support the largest percentage of our members. When we do have members wanting to spend the bucks, they are usually looking at kits that are already matched so they aren't guessing on what part will work with what mod. If you poll members who have made changes to their motor, you'll find that most use the RIVA stage kits (I, II, or III), that are bolt up, ready to go engine mods, no guess work.
Outside the background you say you have, you have no experience in working this forum, solving problems for members who only want to keep their ski/boats running in good shape. The moderators here now, will stick it out with a member who has a problem, troubleshooting their problem till they fix it, if your premium, that includes phone support (under certain circumstances). We would not recommend someone do something that might cause their engine to blow, then leave them hanging. In essence, you directing these guys to do something to their motor that they are unfamilar with, could cause catastrophic consequences. Are you going to back up your talk and stick with this member till he/she gets it back up and running?
Your free to post anything you want, within reason. That's why it's a forum. You might get someone interested in modding their engine. But, I'll always be there to remind the member (especially if its soemone I've known for a long time) about the cost, the work, (machine shop services and costs) and down time when running mods that might make you a hot Seadoo rider, for a short time, cause you to blow or break something and keep you in the garage a large part of your riding season. I don't agree with pumping up the 787 or 951 for recreational riding, they already hit speeds in excess of 60 mph with their already beefy 110 and 130 hp motors. Recreational riding is what people like to do for fun. The forum is designed around a family oriented, recreational use type forum, for informing members who are trying to change their plugs or rebuild their carbs. They want to spend their time on the water, not in the garage. If you want a faster ski, then buy one. The price of 4-TEC's is dropping.
Just last week, I read your intro, meet and greet. I think I made a comment concerning your tactics. Maybe you might better be served helping people at GroupK or one of the many high performance forums. This forum is not based or designed around the race circuit engines. There is always room for a couple performance enhanced ideas, like pump mods, which are less destructive and more cost effective. But, when you go to the extreme of using race gas, ...............you've gone to far for our forum. By the way, with all this talk, I noticed you don't even have a Seadoo listed in your avatar or profile. Do you own one?
Have a great day!..............:
Hide?.... I don't see where that is hiding something about this motor. I've made a statement that is straight to the point. I never said the only mod available was a pump mod. It seems, from interacting with our members over the past few years, that's their choice.
You've only been working this forum for how long?..... Well, ever since I've been here, working as a member then a mod, members want to make their motors last as long as possible, doing the work themselves, most as frugal as I, making their money stretch in a time the economy isn't friendly to putting into our toys.
They might have a manual, might not. A huge percentage of members who do have manuals post questions to me by thread or by PM, asking me to explain something in lamens terms because they dont' understand all the tech terms used in manuals. I'm' quite sure they don't understand your upgrades at all.
Our forum was built on and operates on members who do not race or have a lot of money to dump into an engine. That's not me guessing, that's a fact from reading and posting in this forum for over 2 years. Members who have been ripped off paying $3,000 bucks for a shop to put a new motor in their ski, just to have it blow up and then, the repair facility blame them for the failure (usually blaming their oil pump), is why people are here. They only want to fix or maybe, add a couple horsepower to their motor. (I added 5 mph to my GTX with an impeller change).
There might be a small percentage of members, who might want to use aftermarket mods on their motor but that does not support the largest percentage of our members. When we do have members wanting to spend the bucks, they are usually looking at kits that are already matched so they aren't guessing on what part will work with what mod. If you poll members who have made changes to their motor, you'll find that most use the RIVA stage kits (I, II, or III), that are bolt up, ready to go engine mods, no guess work.
Outside the background you say you have, you have no experience in working this forum, solving problems for members who only want to keep their ski/boats running in good shape. The moderators here now, will stick it out with a member who has a problem, troubleshooting their problem till they fix it, if your premium, that includes phone support (under certain circumstances). We would not recommend someone do something that might cause their engine to blow, then leave them hanging. In essence, you directing these guys to do something to their motor that they are unfamilar with, could cause catastrophic consequences. Are you going to back up your talk and stick with this member till he/she gets it back up and running?
Your free to post anything you want, within reason. That's why it's a forum. You might get someone interested in modding their engine. But, I'll always be there to remind the member (especially if its soemone I've known for a long time) about the cost, the work, (machine shop services and costs) and down time when running mods that might make you a hot Seadoo rider, for a short time, cause you to blow or break something and keep you in the garage a large part of your riding season. I don't agree with pumping up the 787 or 951 for recreational riding, they already hit speeds in excess of 60 mph with their already beefy 110 and 130 hp motors. Recreational riding is what people like to do for fun. The forum is designed around a family oriented, recreational use type forum, for informing members who are trying to change their plugs or rebuild their carbs. They want to spend their time on the water, not in the garage. If you want a faster ski, then buy one. The price of 4-TEC's is dropping.
Just last week, I read your intro, meet and greet. I think I made a comment concerning your tactics. Maybe you might better be served helping people at GroupK or one of the many high performance forums. This forum is not based or designed around the race circuit engines. There is always room for a couple performance enhanced ideas, like pump mods, which are less destructive and more cost effective. But, when you go to the extreme of using race gas, ...............you've gone to far for our forum. By the way, with all this talk, I noticed you don't even have a Seadoo listed in your avatar or profile. Do you own one?
Have a great day!..............:
Last edited by a moderator:
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