Back in the water with the same issue...

[shockerfd]

I don't know what to make of how this boat is acting. Hooked to the hose on land, the boat runs perfect. Throw it in gear and the throttle response is dead on! The rpms react instantly with any slight or sudden throttle movement. I drop it in the water to start the break-in. Idle around for 15 mins. Shut it down and let it cool. Get started back up to run 20% throttle. The throttle has to move almost to 50% just to get the boat to move a little. I can smoothly push throttle up to 3/4 and it just doesn't want to move. So, I idle back in and loaded up for the day. Hooked it to the hose at home to flush and runs perfect. I don't get it. Any help is appreciated.

thanks

 

[seadoo GTS 1993]

Tell us what the compression is, then we can go from there.

 

[shockerfd]

Brand new engine. Just did a comp check anyway and getting 155 psi on both cylinders. I called SBT and they said to check for a blockage in the exhaust. I pulled it all out and everything looks good.

 

[Diesel_7926]

When your at say 50% Throttle what kind of RPM's are you seeing? Did you double check and make sure the Reverse gate is lifting completely out of the way of the jet in Forward?

 

[phough5757]

What kind of shape is the wear-ring and impeller in?

 

[Chester]

Are your throttle plates opening up all the way?

Chester

 

[shockerfd]

The impeller and wear ring are in good shape. The clearance is within specs. The throttle plates do open all the way.

 

[timmyboy76]

gone thru carbs..? and inspect inline filters' o-ring

 

[shockerfd]

gone thru carbs..? and inspect inline filters' o-ring

Yep. Carbs are rebuilt and I sent them to my Seadoo dealer and they went through them too, setting the pop-offs as well. We pulled them apart before we put them back on this engine to make sure filters were clean and no gumming or anything.

 

[timmyboy76]

clip plug wires, and try new plugs?

 

[shockerfd]

Just got back in from trying again. Plugs are brand new and I even put 1 stage hotter to make sure it was burning clean. I'm running fresh fuel at 32:1 premix with break-in oil. SBT told me to bypass the fuel selector switch to rule out it sucking air. I did that and got the same result, however when the switches were being used, I turned it over to reserve as I was moving and the boat acted like it wanted to shut off. If I quickly throw the throttle forward to about 3/4 throttle the boat wants to take off. Moving the throttle slowly and I get nothing. It just bogs about 3000rpms and stays there until the throttle gets to 3/4 position and then takes off. Low speed screw is set to 1 1/2 turns out and high speed has been from 0 to 1/4 turn out with the same result.

 

[johnhibbs]

exhaust hoses

BAd exhaust hoses can cause this. Are they soft in any place? They can delaminate on the inside and block the exhaust flow. See photo on left.

 

[scooper77515]

I am going to go out on a limb, and likely lose a lot of respect on this, but...

The 97 Challenger doesn't have much power at lower rpms. Let me re-phrase that...MY 97 Challenger doesn't have it.

If I keep it under 5000 rpms, it will only be doing a bit more than idle speed, and will not plane.

I pretty much have to open it up to get it moving.

When I was breaking in my new motor, I still went 75-80% throttle to get it planed, then backed off to 4500-5000 to cruise. If I just went up to 5000, the nose would lift up and it would never really pick up speed and plane out. It would feel like it was just revving and pulling, but not going anywhere.

It is a new engine. It has been run, so give it a little throttle and see if it planes and then back off and run it at your break-in speeds. I am guessing it will wake up when you actually rev it enough to wake up those RAVE valves and get it on a plane...

Let us know how it works, so the rest can berate me thoroughly...:cheers:

 

[shockerfd]

I've solved these problems. The dealer set pop-off pressure to 25psi but I was getting a lower psi reading. This was causing flooding at the lower rpms. I changed the springs and brought the pop-off up and boat runs great now.

The reserve problem was an interesting issue I discovered. Someone had a couple of the hoses coming from the fuel valve selector going to the wrong places, not to mention a couple from the baffle that were wrong. It seems I have been slowly fixing the previous owners screw-ups. I guess you never know what you get when you buy used but some things I have found just amazed me.

 

[scooper77515]

Someone had a couple of the hoses coming from the fuel valve selector going to the wrong places, not to mention a couple from the baffle that were wrong.

That could do it.

Still, next time you go out, nail it a bit and see if it wakes up. Even during break-in, you can give it full throttle for a couple seconds, so don't think you need to keep it under 5k.

 

[cjb]

I've solved these problems. The dealer set pop-off pressure to 25psi but I was getting a lower psi reading. This was causing flooding at the lower rpms. I changed the springs and brought the pop-off up and boat runs great now.

The reserve problem was an interesting issue I discovered. Someone had a couple of the hoses coming from the fuel valve selector going to the wrong places, not to mention a couple from the baffle that were wrong. It seems I have been slowly fixing the previous owners screw-ups. I guess you never know what you get when you buy used but some things I have found just amazed me.

I was going to tell you to check that. If it bugs out is because is flooding with gas. Either pop off to low or low speed screws needs to be turn out a little.