no power after chopping throttle

[SharkB8]

701cc squarenose, ported with pipe

Runs fine WFO, I chop the throttle for 2 seconds, pin the throttle again and it trips all over itself for about 1 second like its not getting enough fuel, then takes off like a bat outa hell.

I thought I remembered reading that this is a classic symptom of *something*, but I have searched this site and the other one and can't find it. Any suggestions?

 

[Cliff]

try cleaning the carb real good.

 

[SharkB8]

The carb only has maybe an hour or so riding since being rebuilt by Jetski Solutions.

By your suggestion it sounds as though you think it might be a lean condition somewhere...? I was thinking the same thing but I have reviewed the three carb-tuning guides I could find online and can't find this exact symptom.

 

[SUPERTUNE]

How's the idle set, normal to just a little high?
No throttle screw will cause a very rich condition like this IF idle screw is gone or set to almost nothing.
The other scenario would be a lean stutter or flat hiccup the second you hit the throttle back on after a upper rpm run.
Go bigger on the low jet and or plus lower the pop-off will cure that problem.
Make sure you have the Jetworks flow control valve installed on the stinger feed on the pipe or restricted so you don't have too much water in the pipe/box to clear out when getting back on the throttle.

 

[OCD Solutions]

When my carbs came back from John I had a similar problem, turns out that a small bit of gelatinized fuel was in my pilot jet. I think his process is excellent but there is always a chance that a little gets left behind in the tiny pilot circuits that gets flushed out once the ski is finally running. Pull those carbs and check the pilots, as well as the internal filters and the needle and seat.

 

[SharkB8]

The idle is set just a tad fast.

If it is a lean stutter, is it safe to ride like this for a couple days, as long as I stay away from the "flat spot" where it stutters?

I was planning to do some surf riding tomorrow and I don't have any other size jets and would have to order them by mail. I got my motor back from Group K and just used their jetting.

 

[SharkB8]

Ok, I will give them a good cleaning. Thanks.

 

[SUPERTUNE]

Try setting the low speed screw out more until then...I've worked on some Group k stuff and was not impressed with their total package as far as running was concerned, machine work wise...very nice, just missed the boat performance wise.

 

[SharkB8]

That's what I was thinking, I will try 1/8 and 1/4 turn out and see if it still runs ok everywhere else.

One unrelated question Chuck.... back in 2003 I was living in Naples and got you to bore out and assemble a 650sx motor for me. I only got it about 80% back together and I never started the motor. I am getting back to it now. This ski has sat in a barn in +90 and -20 degree weather for 6 years. I cracked the top end open expecting everything to be bright orange with rust. It was still perfect. Just wondering if you would have put any type of oil on the cylinders or something to keep them looking good. All other metal parts I see sitting around during the hot-cold weather cycles (that causes condensation) gets really rusty after just a year.