03 Superjet w/ riva kit. Won't idle...HELP

[Citizen]

So I bought an 03 super jet with the full Riva RPM kit already installed. Has everything done to it but bore and total loss from what I can tell engine wise.

It has ran like a dream for the last 2 months and I have put an easy 30 tanks of gas through it. Today was the first time it has had any issues. Basically It does not like to idle, if I fall off it will die even with the key still attached. It also seems a lot more sluggish then usual from sub plane speed. Just does not have the pop like it did before.

I am not a gear head by any means but my best guess is either the oil mix ratio i have been using it fouling the plugs and I am getting less spark ( I have not checked the plugs at this point because I do not know what to look for) or I need to adjust my carbs or maybe both? I have run 2 pretty much straight gas tanks through it when i had run out of gas at the lake and had to fuel up at the marina. I am hoping those did not screw it up too badly. I mix the tanks at 50:1 as instructed by the guy i bought it from.

It is still very rideable but If i can get the low power back and a little idle that would be great. Thanks for your time guys this site has been a great resource for me.

 

[SUPERTUNE]

So I bought an 03 super jet with the full Riva RPM kit already installed. Has everything done to it but bore and total loss from what I can tell engine wise.

It has ran like a dream for the last 2 months and I have put an easy 30 tanks of gas through it. Today was the first time it has had any issues. Basically It does not like to idle, if I fall off it will die even with the key still attached. It also seems a lot more sluggish then usual from sub plane speed. Just does not have the pop like it did before.

I am not a gear head by any means but my best guess is either the oil mix ratio i have been using it fouling the plugs and I am getting less spark ( I have not checked the plugs at this point because I do not know what to look for) or I need to adjust my carbs or maybe both? I have run 2 pretty much straight gas tanks through it when i had run out of gas at the lake and had to fuel up at the marina. I am hoping those did not screw it up too badly. I mix the tanks at 50:1 as instructed by the guy i bought it from.

It is still very rideable but If i can get the low power back and a little idle that would be great. Thanks for your time guys this site has been a great resource for me.

What are you saying here? You ran a ski that is premix only (no oil injection pump) on straight gas with no oil mixed in the fuel? If you did...there's your problem, more than likely you runied the pistons and bore and now has bad compression and can only be fixed with at least a top end rebuild.

 

[Citizen]

It was not totally straight gas, the ski had 1/4 of a tank of gas mixed at 50:1 and was then topped off. A buddy using the ski did it the first time and while i figured it was not great for the ski there were no ill effects so i did it once as well. But both times it was just topped off not a total refill of straight gas.

 

[Matt_E]

Bad bad deal.
That's a 200:1 mix in the tank. Way too low. That motor needs oil in the gas, and 3 ounces of gas in 5 gallons isn't cutting it. You are seeing the ill effects now.
Do a compression check. I'll bet it's low. You scored the cylinder/pistons and likely ruined the crank bearings.
You can rent a compression tester at most automotive stores. Check it and see what you get. You should see at least 150 psi if it's good.
If it's bad, you'll need to pull the head off and see what the damage is.

 

[Citizen]

I will head to auto zone today before work to get one. Thanks for the help guys

 

[Matt_E]

Be sure to use an adapter of the same thread length as the spark plugs.

 

[Citizen]

So if i am reading this how to correctly i take both plugs out and set them on top of motor, screw in tester and turn ski over with throttle pinned. Then do same for other side. Is this correct? And I will bring in one of my plugs to make sure the threads match. Thanks again for the help Matt_E

 

[suva]

Sounds like you have it figured out. That motor should be pushing around 170psi at you elevation with the RPM kit.

 

[Mark44]

If you hold the stop button in at the same time you crank the plugs will not fire, also hold the throttle wide open do this with a fully charged battery.

O and put oil in the fuel!

Mark44

 

[Citizen]

150 psi in each almost exactly the same maybe a 2-3 psi difference. How long can i run it out of the water to maybe take a vid so you guys can hear it idle etc. Or would that not help?