Freestyle Port timing for rec ski??

[TheBuzzard]

Pulling the port timing down 2mm is going to make a huge difference to the engine. You may or may not like waterdawg but i wouldnt discount the information he just gave you.
I havent measured up one of these recently so I dont know the timing off the top of my head but its a simple calculation if some one knows the stock timing and rid length to figure out what you would end up with.

lowering the port timing is not going to make the port wider or breathe better. the transfers are now going to have to be raised back up to where they are supposed to be. hacking meat off the bottom of a 62T casting and stuffing it back on, doesnt turn it into a bottom end beast. junk needs lots of technical work to make it rip. you cant make a silk purse out of a sows ear.............

 

[waxhead]

lowering the port timing is not going to make the port wider or breathe better. the transfers are now going to have to be raised back up to where they are supposed to be. hacking meat off the bottom of a 62T casting and stuffing it back on, doesnt turn it into a bottom end beast. junk needs lots of technical work to make it rip. you cant make a silk purse out of a sows ear.............

Whats the stock timing on a 66e , depending on the transfer timing pulling them down maybe the right thing.
As I said I dont know what the stock timing is off the top of my head if you do then you wil be able to supply the information and then I will work out wat it will do to the engine.
Im quite sure you will find these cylinders breath very well compared to a 61x based platform. I would not suggest hacking meat off the bottom but more of a machining process to do it accurately would be far better suited to what you may be trying to achieve. Personally I think the 66e is along way from a sows ear and its technically a much better platform than a 61x its just a shame that it never came in superjets.
Im just glad the affordable cylinder is coming out with some of the 66e cylinders technology to drag the old nail 61x platform into some what modern times

 

[Wiseguy92]

I dont have an opinion on Jeff as we have never spoke. I do believe that he is a guy with alot of expierence with this set up and appriciate his info. I got the msd installed tonight and had to drag it down the the river to see if it picked up. I was pleasently suprised with the result. I ended up with 25 degrees of static timing and called that a good safe starting spot. The bottom improved slightly but the midrange pulled hard. The motor had an entire different sound to it, and sounded like it picked up rpm's. Im going to get a tack and see where it is revving at now. Might be time to take jeffs advice and lower the ports to pick up the bottom hit....

 

[Matt_E]

What pipe are you using?

 

[CARBONX2]

What pipe are you using?

I think he says WDK dry in one of his posts.
I once built a custom pipe for a WB3 using the stock header, the ski jumped out the water on pullaway. I still have the specs if you want. The engine was stock except for R&D Filter and a re-cut oem head to up compression a bit.

 

[senor]

Try injecting water into the pipe,i hear it improves the hit on these pipes.

 

[Wiseguy92]

Thanks for the offer waxhead. The next time i have a head off i will measure the ports to know exactly what it is now. I have been wrenching so much id rather ride it now than turn wrenches!lol
Thanks also for the offer carbonix. I think I will stick with the wdk pipe and work with it.
I am suprised that putting water into the chamber would help the hit senor. ATS Aaron also said that the pipe works well as a wet pipe and the coupler last much longer that way. I will tell you that that pipe is heavy as #$$%# when it is full of water. My coupler has lasted for 15 galons of fuel and is still in tact but is missing some rubber on the ID as a dry pipe. I am planning on getting some tuning in this weekend with the msd so I will let everyone know how she rips after it is dialed better with the new total loss. Thanks again to all

 

[Wiseguy92]

Well here are the port specs on the 66v cyls stock. 200 degrees exhaust with the blade open and 180 closed. The transfers are 123. I took WDK's advice and trimmed 2mm off the cyls. .020" of indicator travel = 1 degree of port duration. Soooo now we are 196 open exhaust, 176 blade closed, and 119 on the transfers. I re cut the domes and ended up with .052" squish with .008 divergence. The compresion ratio now is 17.1-1 and it was 14.6-1 before. I set the static timing to 31 degrees and pull 10 degrees out @7000. I also installed some reed stuffes from protec.
All of that proved to wake the ski up quite a bit. It diddnt rip my arms off like I had hoped, but now the ski is jumps out of the water nice. After chasing carbs again I tried to get some rpm info tonight but the needle on the xp seadoo tack i have has faded soo much I couldnt read it thru the bumps!
I have measured my pump cone and it is 82mm now. From what I hear that is pretty small for good bottom end hit. I am going to open it up to 85mm and see if that helps. Were gaining on it...., thanks for everyones help!
Mike

 

[TheBuzzard]

you said it woke it up quite a bit. would that fall under the significant or insignificant gains? did it make the required difference?

 

[waxhead]

please remove the stuffers and tell me the result as far as power is concerned

 

[circafwsk8r]

i saw wiseguys ski on the 4th of july. I've had a 66e 997 with wdk parts, not a fan at all. haven't seen one in a while and when he popped the hood my thought was man that thing is huge. Hope you get it right man, you live and you learn and i def learned a lot about buying used t on this site without testing it. Theres a lot of shady sellers and usually when stuff is for sale its for a reason. unfortunately our sport is a very small market and this is really the only place to buy used parts. Good luck brotha. hope to see you next year ripping.

 

[Wiseguy92]

When I say improved nicely I mean its reacting n pulling hard like I would expect. I have never riden a 1200 monster or any other big cc ski for that matter. I watch the vids of the pros n it's not hittin like that but it feels impressive now to me. I wouldn't consider trying to flip it the way it was but now I think it's possible.
Hey circa. I don regret buying this ski at all. The seller told me he never had it in the water and I knew it was going to need some shaking down. Really other than the Msd, everything was there to work with. Jeff's advice has picked it up a bunch and I haven't started tuning the pump yet. Few more Tweeks n I should b able to hurt myself on it

 

[Wiseguy92]

Hey wax head. Have you put stuffers in and lost performance on a ski? I have seen a lot of motors and this is the only reed setup I have seen with nothing in the reed box. These reeds are huge also. The stuffer pulls the fuel to the outside petals where the transfers are which is everything in my eyes. Curious why you think they shouldn't work?

 

[waxhead]

I have never seen stuffers add to the power of a two stoke engine. Every time I have fitted them there has been a loss of power

 

[Matt_E]

If I've learned just one thing in 10 years on Jetski forums, it's that wax hates hates hates reed stuffers.

 

[Wiseguy92]

Wow Waxhead, my expierence has been exactly the oppisite. Just goes to show that with all the variables in setup and porting and bla bla bla, some things work and some things dont in certain setups. Im gonna leave them in for now but if I pull them I will let you know how it changes.
I bored the cone to 86 mm tonight. I also talked to Jeff at WDK and got a few more ideas. Clasic problem of changing more than one thing at a time but nice improvements agian tonight. I got my needle painted on my tack and seen that the motor is buzzing right around 7000-7200. Its starting to feel violent so im digin it! I still havent piped water into the pipe yet to try it wet so that is next on my list. Thanks Jason and Jeff big time!!

 

[circafwsk8r]

When I say improved nicely I mean its reacting n pulling hard like I would expect. I have never riden a 1200 monster or any other big cc ski for that matter. I watch the vids of the pros n it's not hittin like that but it feels impressive now to me. I wouldn't consider trying to flip it the way it was but now I think it's possible.
Hey circa. I don regret buying this ski at all. The seller told me he never had it in the water and I knew it was going to need some shaking down. Really other than the Msd, everything was there to work with. Jeff's advice has picked it up a bunch and I haven't started tuning the pump yet. Few more Tweeks n I should b able to hurt myself on it

I regretted trading my xft for a new ROK the first day i rode it. Thats just my style and opinion. Glad your happy w yours.

 

[waxhead]

Wow Waxhead, my expierence has been exactly the oppisite. Just goes to show that with all the variables in setup and porting and bla bla bla, some things work and some things dont in certain setups. Im gonna leave them in for now but if I pull them I will let you know how it changes.
I bored the cone to 86 mm tonight. I also talked to Jeff at WDK and got a few more ideas. Clasic problem of changing more than one thing at a time but nice improvements agian tonight. I got my needle painted on my tack and seen that the motor is buzzing right around 7000-7200. Its starting to feel violent so im digin it! I still havent piped water into the pipe yet to try it wet so that is next on my list. Thanks Jason and Jeff big time!!

That is very suprising. But what ever works

 

[Wiseguy92]

Ya most of the people I have talked to think the Rok is a great all around hull. So many options out there, just find what suits you for sure.
I piped water into the manifold today and liked it. It knocked the bark out of the exhaust just enuff. Soooo responsive tonight at the hit, were on a roll!

 

[kevbo]

you said it woke it up quite a bit. would that fall under the significant or insignificant gains? did it make the required difference?

Its the lack of trapped volume that hurts a stock bore 66E. By lowering the cyl 2MM, a little power was added below the pipe. Peak power and rpm was lowered as a compromise. This is probably a good thing for throttle blippers but it defeats the advantage of using a 66E. The best solution is larger bore cylinders and porting for 7200 rpm.