RX-DI vs RX hull

[2strokeboy]

are there any differences between the rx and rxdi hull?

 

[etemplet]

Just considering the cost of production I think Seadoo would have used the same hull and not made a new fiberglass mold. They look the same to me and run basically the same top end speeds, the difference being the performance of the DI engine which is impressive. I can't help with measurements of figures though sorry. I am waiting on "one of each" from the slo azz engine biulder. LOL

 

[EdwinBland]

@etemplet: is the performance of the DI that noticeable? Are you referring to the smoothness of the running… just trying to understand.

 

[etemplet]

@etemplet: is the performance of the DI that noticeable? Are you referring to the smoothness of the running… just trying to understand.

I restore the old 2-strokes and I don't install a lot of new parts. I use an ultra-sonic cleaner to rebuild the carbs and replace everything with the correct stuff. I think I do a descent job of getting everything right. The DI has power everywhere, no lull, idle, top speed and any point inbetween. Fuel burn is lower on the DI as well. Sweet running ski. No choke, no runaways, no hesitation, easy to start.... what's not to like? I recently bought a DI that sat for 2 years outside. and when I got it home I installed a new battery and it fired right up. I'm not saying it would have been spot on when riding, the compression was 110psi, but I don't think a carb ski would have started right up. I have to romance all the carbs skis after sitting over the winter. Lots of people don't like DIs. I think the DI shows what a well tuned 951 can do. I think they are ferocious and bad azz !!

 

[EdwinBland]

I restore the old 2-strokes and I don't install a lot of new parts. I use an ultra-sonic cleaner to rebuild the carbs and replace everything with the correct stuff. I think I do a descent job of getting everything right. The DI has power everywhere, no lull, idle, top speed and any point inbetween. Fuel burn is lower on the DI as well. Sweet running ski. No choke, no runaways, no hesitation, easy to start.... what's not to like? I recently bought a DI that sat for 2 years outside. and when I got it home I installed a new battery and it fired right up. I'm not saying it would have been spot on when riding, the compression was 110psi, but I don't think a carb ski would have started right up. I have to romance all the carbs skis after sitting over the winter. Lots of people don't like DIs. I think the DI shows what a well tuned 951 can do. I think they are ferocious and bad azz !!

Tx man! I’m in the process of reassembling an RXDI now… It was really hard to get it to not leak between the cylinders and the case… the 951 carb ones I have done were much easier… this was a project “new” engine that leaked in a few places … so I took it apart to fix the air leaks.
I’m looking forward to the break-in….

 

[etemplet]

Tx man! I’m in the process of reassembling an RXDI now… It was really hard to get it to not leak between the cylinders and the case… the 951 carb ones I have done were much easier… this was a project “new” engine that leaked in a few places … so I took it apart to fix the air leaks.
I’m looking forward to the break-in….

Where were the leaks? Crank Internal Lip seals?

During reassembly...Check those oil injection fittings on the crank case. Make sure they are clear and hold a bit of pressure 1/2 pound or so. They should relieve around 3 pounds or so. I got engines back from the builder where these fittings were plugged so the engine wouldn't have lasted long. Test, test, and test again. Good Luck !!

 

[EdwinBland]

Awesome suggestion!
It was leaking above the front most oiler between the cylinder and the case. I’m a little embarrassed… finally on my 3rd try I test fitted without a gasket… and was able to fit a feeler guage in between where it was leaking…0.0015”…
Visually it looked like the rest of the case… it wasn’t banged up… ugh…. I thought it likely needed machining… but my local machinist I trust is an hour drive away… I had seen on some of the forums that people sometimes use flange sealant…not recommended … but sometimes done…so in desperation I put some 518 on both sides of the gasket… that resolved that leak… I’m not proud of it…
I hadn’t been explicitely testing the oilers for blockage… very good suggestion! I’ll retest one at a time… selectively disconnected…
The 2003 service manual doesn’t seem to have a lot of info on the DI leak tests other than a couple pics…with the fuel rail back on.
I’ve often wondered why Seadoo didn’t put something like an oil flow rate sensor… on each line… and alarm when one goes below the expected flow rate… instead of the idiot/empty oil light… it’s such a common failure point…

 

[etemplet]

I use a small hand pump to test the fittings and hook up direct to each one. No oil. The fittings are $30 each and very worth the $$ if you find a questionable one. Good luck. Once that engine is in place the right side is very unfriendly to access. LOL

 

[EdwinBland]

Tx @etemplet ! That makes sense. I like it.