What is this

[Nick94]

Someone tell me and explain what this is. I’m new to jet skis

 

[GGuillot]

Someone tell me and explain what this is. I’m new to jet skis

??? elaborate the 'what' part you're asking...

 

[Nick94]

I guess the picture didn’t upload. Sorry. I’m talking about the red and black things

 

[IDoSeaDoo]

Those plastic things are your RAVE caps. The RAVEs are exhaust valves that change the size of your exhaust port, allowing the ski to change the power curve. There is a spring inside and it keeps them closed until the RPMs are high enough and the exhaust pressure overcomes the spring pressure. Once open, the engine can breathe more freely and achieve the desired performance. Keeping those valves closed allows you to faster build up torque and scavenge some of the fuel/air charge that normally would pass right through the cylinder.

 

[Nick94]

Thanks for the info. I had no idea. I just bought my first ski and before I start doing anything I need to learn stuff about it. Do you know why it might not be starting when it’s warm

 

[IDoSeaDoo]

Either too much or not enough fuel would be my guess, provided you ahve spark. Pull a plug, and with it attached to the boot, hold it against the block and crank it over. You should see a fat spark at the tip. Careful, that's like 10,000V, it'll shock the sh!t out of you

 

[Nick94]

I have good spark and it’s fuel injected. What’s the best way to test them

 

[IDoSeaDoo]

Get the tool to check the fuel pressure. I'm not sure where to get it though. I have a 4tec and I checked my fuel pressure by removing the schrater valve in the fuel test port and clamping a hose on that had a pressure gauge clamped to the other end.

 

[jjsinaz]

I thought the 98 RFI had a 787 engine. The engine in your pic looks like a 951, which would be carbureted. Or is that a pic of another engine not the one in your ski

 

[mikidymac]

Yes, that’s a carbed 951 in the picture.

 

[Nick94]

Your correct that is not my ski

 

[Nick94]

How much fuel pressure should I be getting