SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: SLCKREG on February 14, 2010, 02:20:51 PM
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I don't know if this is normal or not. I just fired the boat up, and am about to toss the driveline back in her so I can call it gtg. It was idling a little ruff but she's pretty cold blooded. So I check the timing and for what ever reason I glance at the carb and it was dripping gas out of both primary boosters, I think that's what the round circular deals are called at the top of each barrel. Is it supposed to be doing that?
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Nope.
It sounds like you either have a butterfly/idle circuit issue, or too high of float level...Dripping is never good, should be a fluffy mist or spray.
Sometimes it is necessary to drill holes in the throttle butterflies to get the idle circuits to work properly (this is the backwoods method) you can also get bigger air bleeds for most applications....
GT
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Dang....I'm about ready to spam this new domi, and go buy an 850. I did have the idle up to 17-1800 because it kept wanting to die. I guess I'll turn the float down a little, I'm not real optimistic here because I already checked it and it seemed o.k. It barely dribbled out of the check hole while idling. This is the same carb I've been fighting a nasty hesitation on. Drilling holes in the butterflies sounds scary.
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Hmmmm I took the float 1/4 turn down, and adjusted the back idle adjustment up and the primary one down a little. For what ever reason it doesn't drip now. Not sure I'm going to make it through the whole domi learning curve.lol
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Dang....I'm about ready to spam this new domi, and go buy an 850. I did have the idle up to 17-1800 because it kept wanting to die. I guess I'll turn the float down a little, I'm not real optimistic here because I already checked it and it seemed o.k. It barely dribbled out of the check hole while idling. This is the same carb I've been fighting a nasty hesitation on. Drilling holes in the butterflies sounds scary.
If the idle circuit is in transition (meaning the transition slot is exposed to open air below the butterfly) it will spittle (it's a word LOL).
It sounds to me like you have an idle mixture issue or something wrong with the idle circuitry....
Most of the time 1000-1100 RPM is enough to keep even the most radical engine alive, so I would start there, try turning the idle adjustment screws all the way in and one turn out and see if that helps, does this have four corner idle adjustment (four screws)?
Should not be a big deal...FWIW, the biggest mistake on the Dominators IMHO is improper accelerator pump adjustment, there needs to be a small amount of gap between the cam and the arm at idle (true idle) and if the arm is somewhat preloaded the accelerator pump will act too small.
You need to get the idle squared away before screwing around with the squirt pumps...
GT
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Thanks GT..fwiw out of the box the accelerator adjustment was way off,it was exactly like you said(already into the pump). I ordered a new cam(for the carb) but I haven't tried it yet. You and some one else said to try a little richer...I went up 3 sizes front and rear. And I probably should have changed 2 things at once but I did. I changed pv's...it took out the 6.5 and went 4.5's. No shooter change yet. Then I never made it back into the water to try it because of starter issues. Oh and yes it has the 4 corner idle adj. The manual says to adjust them for max vacuum...I'll try that once she's warm and on the water. The boat will idle 1000 or so once warmed up, when she's sat for a month or 2 it takes a minute. When I'd sneek into the throttle it wasn't to bad, but if I'd mash it....it would kill the boat(literally).