R&D pipe on stock 701 question

[vdubspeed]

I'm about 100% certain the cooling lines on the 701 I just bought are incorrect. My poor exhaust must have been insanely hot which is why the motor started to run like poop. Even the inner walls of the blaster were turning black! On start up the pisser would sound like an actual exhaust leak until water started flowing. Flowing water was always INSANELY hot and sometimes steaming. I've never owned a modded ski so this is all new to me but I have owned plenty of watercraft.

So here's what I have:
1 line from pump feeding the bottom of the exhaust manifold
1 line out from the head that feeds the initial section of the exhaust.

That part I know is correct. Here's a picture breaking down the craziness. It almost scares me I ran it on the hose like this! The motor was NEVER getting back flushed!

So water leaves 2 and heads to 1. This is where a "T" should be for the flush kit which I will handle.

My questions are really about 3,4, and 5. 4 leads to the pisser. Is 5 supplying the water that was coming out of the pisser? Is this proper or should I consider something else. Please help.

Thanks,

Jason

 

[Fatman]

Looks pretty standard. Water from cylinder head to head pipe, head pipe to "t", part of water over board via pisser and part of water to stinger.

As far as running hot, I'm guessing you either have a gasket leak or a plugged water line. Sometimes the water lines collapse if they get too hot. I'd replace the lines and confirm there isn't a head or manifold gasket leak.

 

[vdubspeed]

funny you say that about the head gasket. But I don't want to get side tracked.

I want to be certain though that inserting a flush line between 1 and 2 is correct? how is the pisser being fed and does that same water feed 3? I'm trying to understand theory also.

Regards,

Jason

 

[Fatman]

You can put the flush were it is. The pisser line (4) is fed from (3). The idea of the pisser is to send part of the water over board instead of loading up the water box. Cylinder head fitting feeds 2, 2 feeds 1 and provides water to the pipe via a small hole inside the head pipe, 1 feeds 3 using the excess water in the head pipe water jacket, and 3 feeds 4 and 5 in your diagram.

 

[vdubspeed]

Damn fatman! Thanks. So that begs the question...are 3 and 1 internally linked which is why the flush kit is cool there?

Thanks! Jason

 

[Fatman]

Exactly. You have a "jacket" of water in between the exterior of the head pipe and the actual exhaust tube which connects 3 and 1 and provides a water stream to the exhaust.

It is possible that the hole inside the head pipe is clogged. You can run air into 1 or 3 and plug the other to see if the hole is clogged.

 

[vdubspeed]

Fatman you have been on point the entire thread.

The theory and waterflow I perfectfully understand now. I'm still rerouting the flush line cause I think it's tacky where it is.

However...when it started to run like poop...it was intermittment but eventually the front cylinder never ran right. Pulling the spark plug shower water drops on it and steam coming out. My money is ALL in on a blown headgasket. Compression is great but water droplets and steam tell a story that can't be denied. Here's the ONLY time I wish it was a seadoo motor cause o-rings are cheaper and easier to replace. LOL.