951 vs 787 engine...

[dsw222]

I am getting very familiar with my boat's 787 engines, and I am becoming comfortable working on them. I am thinking about picking up my first jetski this fall or early spring while the prices are best.

How does the 951 engine compare to the 787? I know the technical details, but I mean in terms of reliability, user preference, performance, cost of repair, etc. I seem to see a lot more posts on here about the 787 than the 951

I'd LOVE to get an 05-07 RXP or RXT, but I think that a 97-01 GTX would be a much smarter choice at this point in time for me (I would like to go with GTX over an XP because i am a large guy at 6'8 300 lbs and i think i would need the stability of a 3 seater)

Can anyone who has owned/worked on/driven both types of engines please give me some feedback?

Thanks!

 

[Dr Honda]

Pesonally... I like the 2 stroke skis. Sure... a brand new toy is always fun, but when you have a failure with a new 4-stroke... it's almost not worth rebuilding. (part it out, and buy a new one) That's why my stable is full of older skis. Not to mention, buying an older ski is the best bang for the buck... someone else takes the depreciation.


OK... 951/947 (what ever you want to call it) is a good engine. It doesn't have that pesky rotary valve that can fail, and since it's gone... it doesn't have the extra 2 hoses going down into the center of the engine. If you decide to go pre-mix... you can remove the entire oil system from the hull. (this is a carb'ed engine)

They are almost as reliable as any of the other Rotax engines. They seem to have a slightly shorter life, but that's because of the HP they put out... and most of the time... people hold them wide open for extended periods of time. As with any engine... lower HP, the longer the life. But, it's not shorter because of a design flaw... they just get more abuse.

If you are looking for stabillity... then get a 3 person ski. That way, you will have more options of what you can do with it. (can't tow a tube with a 2 person ski) Any of the mid 90's to early 2000's 3 person skis will be a good choice for you. Along with the 4 stroke skis... I recommend staying away from the Di or RFI skis. They run great, and are fuel efficient, but when there is a problem with the injection system, it's hard to diagnose, and can get expensive quickly. ($300 for a fuel pump. Ouch)


If you are going to be on the water on Monday... let me know where, and I'll let you ride my skis. (my little 2 seat Si, and my big 4 seat Genesis)

 

[dsw222]

Those are all very good points Honda... thanks for the insight! I'll be watching craig's list like a hawk now that the end of season is approaching

Thanks for the offer... I will be at the Point on Monday to anchor by PNC Park for the Pirates game, and take a few pictures of the 327 foot WWII ship that is supposed to be docked on the North Shore this weekend. Where will you be skiing?

 

[Dr Honda]

Where will you be skiing?

Don't know yet. The wife doesn't seem to be interested in going to the water. We go almost every weekend, and she's almost 4 mo pregnant. I was actually, thinking of going down to the point by myself on the Genesis.


I know the Genesis isn't a SeaDoo ski... but it will give you an idea of what to expect from a large hull with 135hp.

I'll shoot you a PM if I'm going to go out that way.

What time would you hit the water? Since you are going out for the game... I would think you would be starting later in the day.

Should be a nice day. They are predicting 80 and sunny.

 

[dsw222]

Don't know yet. The wife doesn't seem to be interested in going to the water. We go almost every weekend, and she's almost 4 mo pregnant. I was actually, thinking of going down to the point by myself on the Genesis.


I know the Genesis isn't a SeaDoo ski... but it will give you an idea of what to expect from a large hull with 135hp.

I'll shoot you a PM if I'm going to go out that way.

What time would you hit the water. Since you are going out for the game... I would think you would be starting later in the day.

Should be a nice day. They are predicting 80 and sunny.

We are going to the Lady Gaga concert at Console Energy Center sunday night, so we will probably sleep in and make it to the water by 11 or 12. The Pirates game is at 1:30 so we will be over by PNC early to mid afternoon.

Shoot me a PM if you head out that way so I can look out for you (I get PM notifications on my phone). I owe you some drinks after all the help you've given me getting the boat running! :cheers:

I'm going to try to work on it a little bit Saturday morning in Ford City. It starts right up and runs perfect under 5000 RPM, but the top end performance is a bit sketchy. With the RAVEs fully closed and the HSA's fully closed, it seems to bounce around between 6400-6800 RPM or so at WOT (speedo hits just under 60 but used to hit 64 before rebuilds). I then let out the HSA's halfway but this causes the 7000RPM to 5000RPM drop that was occurring when I had the RAVEs fully opened. So..... i think that if I close the HSA's again as they're supposed to be, and open out the RAVEs a small amount, then i am hoping that she will be running as well as she did before the engine and carb rebuilds!

 

[purple_people_eater]

hope you don't mind me adding my 2 cents here but i just bought a 1997 gts and i have to say it is the most stable ski me or my dad have ever been on. we are both big guys too( i'm 6'3" 200 lbs and he is 6'1" 300lbs) and it seats both of us plus my girlfriend no problem. we also have a friend that has a 97 gtx and ever tho his is more "bling" than ours he is having to do a lot more matainance to his 787 than we are to our 717, and ours is not much slower than his. didn't mean to thread hijack, just thought i'd give you my experiance.

 

[dsw222]

hope you don't mind me adding my 2 cents here but i just bought a 1997 gts and i have to say it is the most stable ski me or my dad have ever been on. we are both big guys too( i'm 6'3" 200 lbs and he is 6'1" 300lbs) and it seats both of us plus my girlfriend no problem. we also have a friend that has a 97 gtx and ever tho his is more "bling" than ours he is having to do a lot more matainance to his 787 than we are to our 717, and ours is not much slower than his. didn't mean to thread hijack, just thought i'd give you my experiance.

The whole purpose of my thread was to get some user feedback of skis so I could find a good one to purchase, so no worries about hijacking :cheers:

I'm not familiar with the GTS so I'll check out some information on those too

Thanks, I appreciate the input!

 

[purple_people_eater]

i think they are great. they sit really low in the water and i have yet got mine to flip. i have thrown myself off a few times but have yet to roll the ski. i can even stand on one side and put all my weight on it and not roll, it close tho. and the 717 is great, best of all no rave valves to clean. i got mine off criagslist about two weeks ago with fresh rebuilt motor and jet pump for about $1000, the only problem it had was dess problems. the PO's were running it early this season and the lanyards went bad. i'll attach a pic of mine so you can see what they look like.

 

[TheChad]

DSW,

I can't offer you much information about the 787 vs 951 engine, because I am new to jet ski's all together, but I can offer a little input on stability.

My wife's cousin has a '97 SeaDoo XP (787 I think?), It's EXTREMELY unstable, If you arn't under throttle, it'll roll right over.

I just bought a '96 GSX last week, it has the 787 engine in it, I don't have a Speedo so I don't know how fast it goes, but I know it's quick, I kept up with a late model Yamaha (No idea what model) just fine.

The GSX is about 10x more stable than the XP and is ALOT more fun to drive than a 3-seater. The same day I bought the GSX I lake tested a Yamaha 1100cc 3-seater, it was EXTREMELY stable, probably impossible to fall off of, but it just wasn't fun to drive. It was more like driving a boat then a jet ski, it doesn't do tight corners, it doesn't jump wake well, etc.

The GSX is MUCH more fun to drive and is plenty stable for a guy our size (I'm pretty much exactly the same size as you).

That said, as mentioned if you are going to want to pull a tube or skier, then you'll want the GTX 3-seater. But if not, I think you would probably be happier with a GSX.

Just to add my $0.02 about the 717 engine. The same day I bought my GSX, we bought my wife an '01 GS, which is the same Hull as the GSX but only has the 717 engine.

The 717 does seem like a much more simple engine. But has no where near the performance of the 787! My wife and I drag raced a few times and every single time I was 1/2 way across the width of the lake before she even got up to speed. It's great for her, but being a bigger guy, I have to say the 787 is probably a better choice. The 717 at top speed is probably only slightly slower than the 787, but off the line the 787 has a ton more get-up-and-go than the 717.

Just my $0.02. No Charge!

-TheChad

 

[purple_people_eater]

gsx is still concidered a 3 seeter bud. and if it i just me on the ski i can run with my buddy that has a 787. i just have to work harder to get mine of the line. yes he has more get up but my new 717 can run with him, but idk what has been done to mine when it was rebuilt. but it all comes down to how much you want to spend and personal perferance. and personally i can deal with a little less take off power than having to pull apart my ski every other weekend to clean rave valves lol. i'm way to busy for that. :cheers:

 

[TheChad]

gsx is still concidered a 3 seeter bud. and if it i just me on the ski i can run with my buddy that has a 787. i just have to work harder to get mine of the line. yes he has more get up but my new 717 can run with him, but idk what has been done to mine when it was rebuilt. but it all comes down to how much you want to spend and personal perferance. and personally i can deal with a little less take off power than having to pull apart my ski every other weekend to clean rave valves lol. i'm way to busy for that. :cheers:

I'm sorry but you are incorrect. Just to be sure, I just checked the Operators manual and the GSX is listed as a 2 passenger and is no where near as long as a 3 passenger.

As for cleaning rave valves every weekend, that's a big over exageration, unless of course you put 50 hours on your PWC durning the week? Since they are only suggested to be cleaned every 50 hours.

The RAVE valves are also right on top of the engine, so it's not like they are hard to get to or hard to take apart. I would consider it about the same as cleaning/changing the air filter on your car/truck.

The 717 seems to be a great engine though, and I definitly am not advising against it! But eveyone likes a little more power. It's all a matter of what a person wants. I think most guys would get bored with the 717 much sooner than the 787.

-TheChad

 

[purple_people_eater]

sorry about that i was thinking GTX:ack: not gsx

but yes me and my buddy do run about 2-3 hours after work everyday and about 10 hours on weekends. and he always complains about having to clean his valves. i'm the kind of guy that likes little maintanice. and being a traveling computer repair man, i just want to put my ski in the water and go at the end of the day and go. but hey i'm sure we could go back and forth all day :boxing_smiley: lol. but like you said it about what a guys wants. :cheers:

 

[Wire4Money]

sorry about that i was thinking GTX:ack: not gsx

but yes me and my buddy do run about 2-3 hours after work everyday and about 10 hours on weekends. and he always complains about having to clean his valves. i'm the kind of guy that likes little maintanice. and being a traveling computer repair man, i just want to put my ski in the water and go at the end of the day and go. but hey i'm sure we could go back and forth all day :boxing_smiley: lol. but like you said it about what a guys wants. :cheers:

He needs to try a decent oil.

 

[revhardXP]

sorry about that i was thinking GTX:ack: not gsx

but yes me and my buddy do run about 2-3 hours after work everyday and about 10 hours on weekends. and he always complains about having to clean his valves. i'm the kind of guy that likes little maintanice. and being a traveling computer repair man, i just want to put my ski in the water and go at the end of the day and go. but hey i'm sure we could go back and forth all day :boxing_smiley: lol. but like you said it about what a guys wants. :cheers:

Just last week I worked on a 96 XP with original and untouched rave valves that still operated fully - 12 years later. Im not saying thats best practice - but it sounds like your friend needs to devote his energy and effort into other parts of the ski, because his raves are working fine. And Ill take the trusty 787 over a 720 any day of the week.