1997 GTI. Is the 717 a good engine? (2024)

See the boat in my avatar??? that has a single 720 (717) engine in it. 85 hp is plenty to get a couple people wet, and push that ski close to 50 mph. It's also a very reliable engine.

If the price is right... take the ski out for a water trial, and if it runs good... buy it. Just an FYI... do not just start it on the trailer, and say "OK." A crap ski will start, and sound ok on the trailer... but all the problems will come out once it hits the water.

I have a 96 GTI with a 720. Great ski, very stable, and the 720 (in my opinion) is the most reliable and service free engine that SeaDoo has ever used. I have never had any engine work done on this ski. Regular maintance is pretty easy to perform yourself.

My ski, when riding by myself (165lb.) on calm water tops out at a respectable 50-52mph. Not the fastest ski but 50mph is plenty fast for me.

Lou

LouStrau said:

I have a 96 GTI with a 720. Great ski, very stable, and the 720 (in my opinion) is the most reliable and service free engine that SeaDoo has ever used. I have never had any engine work done on this ski. Regular maintance is pretty easy to perform yourself.

My ski, when riding by myself (165lb.) on calm water tops out at a respectable 50-52mph. Not the fastest ski but 50mph is plenty fast for me.

Lou

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+1, except for the statement in bold.

The 787 engine has that title, the only mainaince the 787 has that the 717 doesn't is the RAVE valves, the 787 is known for having a bullet proof bottom end. That said, the 717 is a great engine, easy to work on and if taken care of right will last hundreds of hours between rebuilds.

I have 2 GS series Ski's, a '96 GSX w/787 engine and a '01 GS w/717 engine. The 787 is alot smoother, much more responsive and obviously faster and more torque. However the 717 is more simple and has plenty of power. If you were wanting to tow a skier, I would suggest getting a GTX with a 787 engine, but for what you say you want to use it for, you will be very happy with a 717 engine.

-TheChad

I did state "in my opinion" so I have my opinion and you have yours. The bottom end is pretty much the same on both engines, the main difference besides the 787 having more CC's is the rotary valve (no maintance) vs Rave valves.

I guess we have a friendly debate going here.

Lou

Hey Lou... Both engines have rotary valves. (just an FYI) It's on the intake side. The RAVE valves are on the exhaust. But, since we are having a debate... I will give my vote for the 720 engine of the all time best seadoo engine.

The 720 and 800 are both great engines... but, in my opinion... the 720 would win for a couple reasons.

1) no RAVE valve to need surviving. (this alone makes it the winner, because it makes yearly maintenance easier)
2) best power output for it's length of life.
3) On rare occasion, the 800's counter balance can come loose, and destroy the engine. (720 doesn't have one)
4) the 800's ignition pick-up can break loose, and leave you stranded. (the 720 doesn't have one)

OK... all of that is petty, and the engine should live as long as the 720... but that's why the 720 would win.

Tony, Thanks for the vote.

Lou

LouStrau said:

I did state "in my opinion" so I have my opinion and you have yours. The bottom end is pretty much the same on both engines, the main difference besides the 787 having more CC's is the rotary valve (no maintance) vs Rave valves.

I guess we have a friendly debate going here.

Lou

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I am definitly not challenging your opinion in any way. the 'industry' from what I have read/understand has claimed the 787 to be "the best most reliable engine brp/seadoo has ever made". That said the 'industry' is basically the racers/performance shops and the 717 was rarly if ever a race engine. I've read Bill O'Nead say he's had a 787 bored out over 1000cc before.

Anyway, the 717 is a great engine, especially for someone who doesn't care about speed/torque, wants something simple and is just cruising.

As I mentioned, I have a ski with both engines, I prefer the 787, mainly because it's quite a bit smoother thanks to the counter balance, and has more torque. It's faster as well, but the 717 ski is plenty fast, we run out of lake before you can think "I wish this ski was faster".

RE: "Rotary valve (No maintaince vs Rave valves", Both engines have the rotary valve, that is on the intake behind the carb(s). The RAVE valves are on the exhaust and as noted are on the 787 and not the 717. The RAVE valves would be the only "maintaince" item that the 717 doesn't have, but they are really easy to clean/maintain.

(Dr Honda beat me to the punch)

I consider both these engines to be superior to the 951 engine which is known to shatter pistons around 150 hours.

-TheChad

TheChad said:

I consider both these engines to be superior to the 951 engine which is known to shatter pistons around 150 hours.

-TheChad

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Also... there was a "First gen" 951 that was total crap. We don't even really talk about them here because most of them failed in the warranty period. So... no one should still have one.

Dr Honda said:

Hey Lou... Both engines have rotary valves. (just an FYI) It's on the intake side. The RAVE valves are on the exhaust. But, since we are having a debate... I will give my vote for the 720 engine of the all time best seadoo engine.

The 720 and 800 are both great engines... but, in my opinion... the 720 would win for a couple reasons.

1) no RAVE valve to need surviving. (this alone makes it the winner, because it makes yearly maintenance easier)
2) best power output for it's length of life.
3) On rare occasion, the 800's counter balance can come loose, and destroy the engine.
4) the 800's ignition pick-up can break loose, and leave you stranded.

OK... all of that is petty, and the engine should live as long as the 720... but that's why the 720 would win.

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To be fair then, we have to mention the 717's weak intake manifold cracking with an aftermarket flame arrestor or if the support bracked isn't installed or loose.

This is just an observation, but I've seen far more threads about 717 bottom end's going then 787's.

The statement in bold is debatable at best because a 787 vs 717 has basically the same life span if maintained properly and the 787 has more power.

-TheChad

I like this thread.

Anyone else have an opinion, can be any engine SeaDoo has used, excluding 4 strokes.

Lou

LouStrau said:

I like this thread.

Anyone else have an opinion, can be any engine SeaDoo has used, excluding 4 strokes.

See Also

1997-2000 Sea-Doo GS 720 (717) Specs and Review [Video]

Lou

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I would actually sum it up as: SeaDoo's 700 series engines are the best most reliable engines SeaDoo/Rotax ever made.

-TheChad

TheChad said:

To be fair then, we have to mention the 717's weak intake manifold cracking with an aftermarket flame arrestor or if the support bracked isn't installed or loose.

This is just an observation, but I've seen far more threads about 717 bottom end's going then 787's.

The statement in bold is debatable at best because a 787 vs 717 has basically the same life span if maintained properly and the 787 has more power.

-TheChad

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The 720 manifolds weren't weak. If you put on the aftermarket flame arestor, and remove the factory suport... yes, they will crack. BUT... that's a case of an aftermarket part screwing up the factory design. (I rebut your logic ) As an FYI... the same thing happens with Kawasaki's.

Bottom ends.... well..... with the type of use these get, that's a moot point. The crank and bearings fail premature anyway since they are constantly seeing moisture. But... ok... ill let you have that one.

The life span thing was pointed mostly at the smaller engines. They have about the same life... but the 720 made more power.

TheChad said:

I would actually sum it up as: SeaDoo's 700 series engines are the best most reliable engines SeaDoo/Rotax ever made.

-TheChad

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Chad,

Good one, you should be a Politician.

Lou

Uh O, here we go again. Honestly I don't have experience with the 951, I've heard there are reliability probs. with this engine, especially older 951's. I guess you do also.

Anyway you won't hear from me anything about this engine being the best.

Lou

c good said:

I'm also considering a 1999 GTX with the 951 engine. How would I determine if it's a "First Generation" 951?

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http://www.seadooforum.com/showthread.php?38906-Changing-951-from-White-to-Silver

If taken care of a 951 can be a very reliable engine. There were problems early on with the 951. They are not #1 on the most dependable list, but if taken care of properly, they can last a long time.
I own 657 engines and a 951 engine at the present time. I like them both. I have owned 717's (glorified 657) before and liked them also.

Hello guys
I just bought my fist seadoo it is 2002 gti 717cc
I bought it from an old guy that only had 6 hours each season on it, the machine is super clean always run on a fresh water Barrie, Canada
He always have it checked in the marina. However he never cleaned the carbs or any valve

I was looking for any article that is explaining the regular maintaince and how to take of it

I did the compression test it was 135 psi in each

What should I do next ?

LouDoo said:

I like this thread.

Anyone else have an opinion, can be any engine SeaDoo has used, excluding 4 strokes.

Lou

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Yeah I have one, here goes, the 717 started off as a 587, then it morphed into a 657 by adding a longer stroke and bigger bore, then into a 720 by adding an even bigger bore, at 717 cc's it is maxed out, this is why most people do not mod 717's.

The 787 is a whole new design that does not have those drawbacks, it can be bored much bigger and with a VE cylinder can go out to 920 cc's or larger.

Comparing these two is comparing apples and oranges , as far as reliability goes they are pretty much dead even.