SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: Stevecat on July 27, 2009, 04:17:49 PM
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Hi - need suggestions on what might cause this. All 4 seasons that I used my boat, the motor has always idled about 1000 and never had issues running at idle.
This season, after I got all the wire shorting issues resolved I have had good times so far.
Last two times out - weather is unusually hot here in P-town, I have had to run a long time at idle while trying to get noob skiiers out of the water. After running at idle for 15 mins or so, temp gage still says motor is at 120-140, but idle slowly drops down to 600 (which I like) and runs well there for 10 minutes. After that, it will not run at idle - will die. Runs OK if I goose the throttle back up to 1,000 or more.
What might this be caused from? Thanks!
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Wow that's kinda bizzar.....every boat I've had tends to idle a little faster once warmed up. I wonder if it's a jetting thing? How do your plugs look? Fuel pressure o.k. the whole time?
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Mine idles a lot lower when warmed up. Just always figured it was something in the Unilite that reacts to temp. Maybe not, lol.
I dunno, could be a carb issue, I suppose, I know it's not on mine as the carbs are actually MUCH colder after running hard than they are at startup. Could also be something in the dizzy reacting to temp. Hellifiknow.
be interesting to see what you find tho.
Ray
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Hey Steve, does it run rich at idle (can you smell it)? If it runs richer at idle when it's warmed up it may just be too fat...or the float level may just be a tad too high.
One other thing to check is if it pulls fuel from the venturi's while it's idleing, could be two things if this is the case.
One, the float level is too high or a bad power valve (if you gots one)...
Two, the throttle butterflies are partially open and may need to be number drilled to get the idle circuit to work properly, I know I had to drill mine to .010" (I think) to get some adjustability. ;)
On another note, how sure are you of the engine temp?, could be getting some hot spots during a long idle time (even if the gauge says everythings Groovey :thumbup:
Good luck, let us know how things turn out.
GT