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margo
08-23-2007, 02:52 PM
Just purchased a minx with a 350 merc.2 barrel carb...Supposedly the boat was sitting for a while It starts good but will only run at a fast throttle aroun 2000 rpm. if you bring it down it will stall...Put in new filter didn,t help Was told may be the antisiphon valve on the fuel tank...Hope not can you get at it...Going to try running it out of a jug of fuel and see what happens...The engine is a crate and supposedly has only 10 hrs. on it Who knows some people will tell you anything to make a sale...Any help would be appreciated...Thanks Joe..

zelatore
08-23-2007, 07:13 PM
I am not a carb expert by any means, but I doubt it's the anti-siphon valve or similar as I would expect that to limit fuel flow and cause the opposite of what you're seeing. i.e. it would idle but not run at higher rpm.

I would suspect the idle circuit in the carb is gummed up from old gas, especially if it's been sitting for a while as you mentioned.

Of course, that means the 2bbl carb is competely trashed and will have to be replaced with a 4bbl. You know, for reliability. :wink:

margo
08-24-2007, 06:12 AM
I am not a carb expert by any means, but I doubt it's the anti-siphon valve or similar as I would expect that to limit fuel flow and cause the opposite of what you're seeing. i.e. it would idle but not run at higher rpm.
I would suspect the idle circuit in the carb is gummed up from old gas, especially if it's been sitting for a while as you mentioned.
Of course, that means the 2bbl carb is competely trashed and will have to be replaced with a 4bbl. You know, for reliability. :wink:
That means i have to replace the intake also correct ..Thanks for the imfo i was thinking the same thing about running at speed and needng more fuel it wouldn,t get it....Joe

Sweet little 16
08-24-2007, 08:22 AM
is this the red and white minx that past me on the NY state thruway at exit 16 wed afternoon around 2pm or so??? dark pickup pulling it???

good luck with the boat

I would stick with the 2bbl for now get her running have the existing carb looked at run her for the rest of the season and then make out your Christmas list ;)

if you want to eliminate a fuel pickup /tank/supply line problem hook up a portable tank and run her she what she does

zelatore
08-24-2007, 09:50 AM
margo, I was only kidding about the 4bbl - as we know, the search for more power starts after the first run and doesn't end until the boat is sold.

16 is right, you should try to iron out the issues with the current set-up before starting mods. (but yes, you would have to replace the intake to fit a 4bbl carb)

My feeling is that if it runs good at high rpm but doesn't idle, you don't have a fuel supply problem. But as noted above, a very easy way to test that is with a jerry can and lenght of hose.

margo
08-24-2007, 02:49 PM
Thanks guys yes that was me on the nys twy.black pickup chev....Took off the carb getting it rebuilt have to start somewhere...Been wet sanding and buffing all day little to hot out but this is what i,m good at...Red is comeing out beautiful lot of work but worth it it,s a Donzi...Using meguires heavy duty compound then there cleaner wax after wet sanding with 1000...Joe

mdiggs
08-24-2007, 03:13 PM
See also the replies in a similar thread posted earlier in the week (different engine, but same situation and symptoms):

http://www.donzi.net/forums/showthread.php?t=50229

Seems like this might be a fairly common issue after storage.

mdiggs
08-24-2007, 06:04 PM
You might also want to check out the responses to my thread on idle problems after storage. Different motor, but sounds like a similar symptom in similar situation.

http://www.donzi.net/forums/showthread.php?t=50229

I thought I posted this before, but I never saw it show up....probably attached it irrelevantly to some other thread. :-<>

mdiggs
08-25-2007, 12:18 PM
Take a look at the responses to my thread on "Idle Problems after Storage." Some of the responses there might be relevant.