93 xp with a 720 and Factory Pipe Exhaust Help Please

[xprider02]

I put a freshly rebuild 720 engine with 150 psi in both cylinders and a 720 electrical box in a 93 xp that origionally had a 650 in it. I have a Factory Pipe Exhaust on it and an Ultrac Head with an Ultrac water box. (Ultrac is a brand name I think they don't exsist anymore) It has the electronicly controlled water injection that the pipe came with hooked up as well. The problem is I am not sure if I have the cooling system correct. The cylinders seem a little too hot when you touch them while it is idleing. You can still hold you hand on them and the head but I am afraid of taking it out and it over heat. I ran the water lines according to the factory pipe drawing but not a 100% on it.

Also any suggestions on jetting? I have it at about what factory pipe suggested but not sure it is correct.

Any advice would be appreciated

I can put up pictures of the ski and engine and hose routing if you would like

 

[Dr Honda]

The 2 engines do have a little different cooling hook ups. Follow the diagram below, and you will be fine. Oh... and the engine will get hot while running, and you can probably touch it without burning yourself... but it will be hot.

As far as jetting. Use EXACTLY what Factory Pipe says to use. If you don't... you will wind up melting your rear piston.

Let us know how it runs... and post a pic or two. It should be fun with 100 stuffed in it.

 

[jwick86]

Why would you post a pic of factory cooling lines? Thats not how FPP wants you to run them. If he followed FPP, he's fine. Thats like telling him to run stock jetting.

Your cylinders shouldn't be getting hot when idling unless its idling for a while and your cooling system isn't pushing water through it to cool down.

Have you pulled your exit line at all to make sure its flowing water? You can take the line closest to the air box on the motor (right hand side line looking from behind the ski), take it off on the trailer and see if the motor is flowing water through.

 

[xprider02]

yes it is flowing water through the exit. I have the cooling system ran exactly how Factory Pipe recomends. The cylinders just seem to be getting hotter then others I have felt while running with stock pipe, head, etc.

I have the jetting pretty much exactly what fpp says. The pop off is at about 35 instead off the fpp recommended 44psi.

But that is richer which would not cause it to get hot or blow up. Maybe just foul plugs and smoke. I tried running the same needle and seat and springs they recomended to make the pop off 44 psi and it made it about 20 psi. so I figured I would just use 1.5 needle and seat sense that would flow more fuel and the next size up spring and made the pop off 35 psi I would rather be kind of rich then lean or really rich..... for now at least....