R&D Pipe identification and setup help

[RBS145]

Can anybody shed some light on which pipe this is and maybe help me get it set up? Check out the diagram I drew up, it's my best guess and a starting point of how I figured it should be hooked up. But, really I have no idea as I'm left with the two stinger fittings and the straight fitting unused.

The two 90 degree fittings on the head pipe are into the same water jacket, the straight fitting is an injection into the head pipe exhaust chamber. Then I'm left with the two in the stinger.

Any advice is appreciated, the guy who built the motor and sold the setup to me said I should be running 3 pissers as well, but I don't get how.

 

[RBS145]

Bump, anybody have any suggestions? I ended up setting it up like this diagram. It's really sluggish out of the hole, but clears out in the midrange then it's fine.

Any help would be appreciated, I know lots of tuning 2 stroke bikes. Nothing about skis though.

 

[fastgtfairlane]

Bump, anybody have any suggestions? I ended up setting it up like this diagram. It's really sluggish out of the hole, but clears out in the midrange then it's fine.

Any help would be appreciated, I know lots of tuning 2 stroke bikes. Nothing about skis though.

View attachment 429882

I'd try plugging one of the 2 outlets at the stinger and run that outlet overboard to a pisser. A flow control valve to limit water into the stinger at low rpms will help bottom end response. Sounds like you have too much water in your exhaust

 

[WFO Speedracer]

It looks like you have two lines going into the stinger, usually you run one and plug one, R&D pipes usually have a lot of extra fittings , I know my R&D Seadoo pipe does , as far as I know you never run two lines into the stinger just one.. Like Fast siad too much water in the exhaust. Have you contacted R&D for the water routing instructions., that would be my first step.

 

[SUPERJET-113]

R&D has been closed since 2018. The owner Bill Chapin lived here in Havasu and tested parts daily every morning down at Body Beach.
As far as the pipe set-up I dont know anything about that...

 

[WFO Speedracer]

I found this pic but no water line routing for that pipe so far. This link is about as good as I can do for you hoss. BTW they call it a snail pipe.

750 sx r&d pipe. need help - PWCToday

Post topics relevant to PWCs in this Kawasaki Jetski Forum.

www.pwctoday.com

 

[TheBuzzard]

It's as simple as water in water out. Blow on a nipple and where the air comes out is the other end. Water in there and water out the other end.
From the pump, it's water to the bottom of the exhaust manifold, either one or 2 fittings, thru the motor and out the head. If you have multiple head fittings, one goes to the head pipe and out the head pipe to the stinger. Out the head if more than one to a pisser. Line from head pipe to stinger should be Td to an out pisser and a restrictor or flow controll valve to restrict water to the stinger. The newer coffman head pipes had 3 nipples. One went to a pisser to reduce water pressure in the head pipe. Less pressure dumped less water into the stream and dried the system out and added power. Not sure if that's what yours has or not.

 

[RBS145]

I'd try plugging one of the 2 outlets at the stinger and run that outlet overboard to a pisser. A flow control valve to limit water into the stinger at low rpms will help bottom end response. Sounds like you have too much water in your exhaust

Definitely sounds right, it just falls on it's face till it clears in the upper RPM's. I'll give this a go.

I found this pic but no water line routing for that pipe so far. This link is about as good as I can do for you hoss. BTW they call it a snail pipe.

750 sx r&d pipe. need help - PWCToday

Post topics relevant to PWCs in this Kawasaki Jetski Forum.

www.pwctoday.com

Thank you! Just knowing the pipe model has helped with my researching.

It's as simple as water in water out. Blow on a nipple and where the air comes out is the other end. Water in there and water out the other end.
From the pump, it's water to the bottom of the exhaust manifold, either one or 2 fittings, thru the motor and out the head. If you have multiple head fittings, one goes to the head pipe and out the head pipe to the stinger. Out the head if more than one to a pisser. Line from head pipe to stinger should be Td to an out pisser and a restrictor or flow controll valve to restrict water to the stinger. The newer coffman head pipes had 3 nipples. One went to a pisser to reduce water pressure in the head pipe. Less pressure dumped less water into the stream and dried the system out and added power. Not sure if that's what yours has or not.

Makes sense, the head pipe has a water jacket internally to keep water out of the actual exhaust, I will try the valves/restrictors to get some water out of the pipe itself. It is a dual cooling setup from the pump and head water is out to a pisser from both fittings.

Thanks to all of you for the help, I'm taking it out tomorrow and will play around with different settings. I'll report back on how it goes.

 

[Half flip95]

I thought the snail pipe was the 750 pipe R&D, i had one of those

 

[fastgtfairlane]

With dual cooling lines, I like to run a line to the engine and one line to the headpipe. That way you can tune the exhaust temp with water separate of the engine.

 

[RBS145]

I thought the snail pipe was the 750 pipe R&D, i had one of those

Yes, it is. It also fits the Yamaha flange.

With dual cooling lines, I like to run a line to the engine and one line to the headpipe. That way you can tune the exhaust temp with water separate of the engine.

Yeah, that's how it's setup. How do you measure the exhaust temps? With a gun or an added sensor somewhere?

 

[fastgtfairlane]

You can spray water on the chamber after a hard wot run. As long as it's not sizzling it should be fine. When it gets too hot it will loose power as well. Really something you'll want to play with and get it where it feels best for your riding style. Cooler pipe will make more bottom and less top end rpm and a hotter pipe will make more rpm up top but may loose a little power on the bottom.

 

[Half flip95]

Yes, it is. It also fits the Yamaha flange.

No, It had a different chamber and stinger

 

[Half flip95]

this

 

[WFO Speedracer]

I would have called any of those snail pipes but regretably there is not a lot of info on R&d pipes that has filtered it 's way to the internet.

 

[WFO Speedracer]

I dug this up and it may be of some help, I know I ran into similiar issues trying to find the water routing on my R&D Seadoo 787 pipe, not a lot of info out there.

Coffman pipe on 750 sx - Greenhulk Personal Watercraft Performance Forums

For subjects such as talking to your fellow Kawi friends on subjects not related to specific ski performance such as forum changes, asking for general help, or showing something about kawi's that don't belong in the ski areas.

greenhulk.net

 

[Storbeck]

I like to buy temp strips from McMaster. Sticj one on the head pipe, one on chamber, one on waterbox. I would shoot for around 170 deg on all of them. You'll probably need to run hot water out of the motor to the head pipe and bypass some of it to get it that warm.

 

[RBS145]

No, It had a different chamber and stinger

I can't speak to that part. But, this is a Kawi pipe on a Yamaha engine. The bolt pattern works, the reason I have it mixed and matched like this is for the space I have in my mini boat. I'm limited to what would fit in it. Superjet pipes all seemed to be to long past the flywheel side of the engine to fit.

I dug this up and it may be of some help, I know I ran into similiar issues trying to find the water routing on my R&D Seadoo 787 pipe, not a lot of info out there.

Coffman pipe on 750 sx - Greenhulk Personal Watercraft Performance Forums

For subjects such as talking to your fellow Kawi friends on subjects not related to specific ski performance such as forum changes, asking for general help, or showing something about kawi's that don't belong in the ski areas.

greenhulk.net

Thank you, I have it set up now similar how 7th post has it layed out. But, with valves to control both injection points flow and the rest out a pisser. I used my great paint skills to draw out what I pictured they said. I will go try it out this weekend. Maybe it'll be useful for someone down the road too. The valves should make adjustments easier. Any water that is blocked by the valves will go out the pisser.

You can spray water on the chamber after a hard wot run. As long as it's not sizzling it should be fine. When it gets too hot it will loose power as well. Really something you'll want to play with and get it where it feels best for your riding style. Cooler pipe will make more bottom and less top end rpm and a hotter pipe will make more rpm up top but may loose a little power on the bottom.

Sounds good to me. I'll play with different settings on the valves and try this out. Either way, it'll have a way less water in there and will hopefully be noticeable right away.

I like to buy temp strips from McMaster. Sticj one on the head pipe, one on chamber, one on waterbox. I would shoot for around 170 deg on all of them. You'll probably need to run hot water out of the motor to the head pipe and bypass some of it to get it that warm.

Thanks, I'll grab some of those and get them on here.

 

[sturat]

this

THIS is the "snail pipe". Not only for it's shape but also because it's a slow pipe. The exhaust pictured looks, to me, like a bastardized seadoo pipe.

edit: it is a seadoo 720 pipe with a modified stinger and mismatched secondary chamber. I cant remember what the secondary chamber is off of.

 

[sturat]