Identifying stock vs modded valvetrain

[The Von Matrices]

I have an '06 RXP that I bought three years ago. It's been working fine for that whole time so I haven't had a desire or need to change anything on it.

I do know that the previous owner had done some modifications, but I've never been sure how far he went because I never took apart the engine. I now have replace a leaky valve cover gasket and I figured it's a good time to figure out if he had done anything to the valvetrain.

How can I tell whether an engine has a stock or aftermarket camshaft and also whether it has the stock or upgraded springs/retainers? What signs would I be looking for? Is it even possible to tell if it isn't a stock camshaft without taking it apart and measuring the lobes?

[SplishSplash]

Whats it performance? Top speed at what RPM. That will give you a hint if its modified.
Post a pic of the valve train. We can identify if its stock retainers or aftermarket.

[John's truck]

Post pics of the retainers and springs and valve stems. For the cam, the way to be sure would be to remove the cam from the head and check it for a SeaDoo part number. Should be 420837851 for 06-08 or 09. If you confirm that’s what you have, a factory 04-05 cam (ending 628 or 629 part number) would be a solid increase for cheap

[The Von Matrices]

I haven't taken off the valve cover yet but will take pictures and attach them when I do.

Whats it performance? Top speed at what RPM. That will give you a hint if its modified.

The guy I bought it from was a nice, honest guy - we had a mutual friend - and when I said I was concerned about reliability he flashed the ECU from whatever he was using to a 255-ish tune before he gave it to me. It has the larger fuel injectors and external intercooler, and the rev limiter is definitely 8000rpm. But that rev limit does rule out the better retainers because I don't know what tune he was using before that. If it was a stock 255 tune I assume it would run poorly with a different cam?

Post pics of the retainers and springs and valve stems. For the cam, the way to be sure would be to remove the cam from the head and check it for a SeaDoo part number. Should be 420837851 for 06-08 or 09. If you confirm that’s what you have, a factory 04-05 cam (ending 628 or 629 part number) would be a solid increase for cheap

Where on the camshaft would the part number be? I'm not enthusiastic about taking off the camshaft and hope I could see the part number without all the disassembly.

[John's truck]

It’s in the center of the cam, at the end the timing gear bolts to. If you take the breather off the back of the head, you might be able to see it. I forget if the piece of plastic covers it up.




My ski is running on a stock 2008 RXPX 255 ECU, X charger, 42 lb injectors, and a 2005 -629 cam. It runs fine, but is a little lean. There’s definitely a difference in tuning between the 215 ECU’s and the 255. But it will run.

[The Von Matrices]

ItÔÇÖs in the center of the cam, at the end the timing gear bolts to. If you take the breather off the back of the head, you might be able to see it. I forget if the piece of plastic covers it up.

My ski is running on a stock 2008 RXPX 255 ECU, X charger, 42 lb injectors, and a 2005 -629 cam. It runs fine, but is a little lean. ThereÔÇÖs definitely a difference in tuning between the 215 ECUÔÇÖs and the 255. But it will run.

I took the valve cover off tonight. I couldn't see the part numbers on the cam and I didn't want to take it out because I don't have new bolts for the lifters. But I did take pictures of the springs and retainers. It's probably obvious to someone who knows but this is the first time I've seen the valves on a 4tec so I have no reference. If the springs and retainers are stock then I think I can rule out an aftermarket cam even without seeing the part number.

[tiderider]

The springs look stock. But the retainers are titanium.

[John's truck]

You could get a good look at the cam by taking the rocker shaft and rockers off, but like you said you donÔÇÖt have bolts. ARPÔÇÖs are like $35 bucks though.



What IÔÇÖm talking about with the part numbers is on the end of the cam stick, under the breather. You donÔÇÖt need to remove the rockers to see it

[The Von Matrices]

I'll get a better look at the cam part number when I get back to the ski in a few days. I didn't realize you could see it by removing the PCV valve.

Do you know why someone would put in titanium retainers but not upgrade the springs?

[John's truck]

I'll get a better look at the cam part number when I get back to the ski in a few days. I didn't realize you could see it by removing the PCV valve.

Do you know why someone would put in titanium retainers but not upgrade the springs?

Stock springs are pretty good. IÔÇÖm using stock springs, titanium retainers, and Supertech valves. But IÔÇÖm only using a 629 cam and donÔÇÖt plan on spinning crazy like 9000+

[tiderider]

I'll get a better look at the cam part number when I get back to the ski in a few days. I didn't realize you could see it by removing the PCV valve.

Do you know why someone would put in titanium retainers but not upgrade the springs?

If there is no yellow markings on the springs, they may have been upgraded as well.

[John's truck]

If there is no yellow markings on the springs, they may have been upgraded as well.

Yep. Here’s a pic of the yellow on mine