Carb question

[bspeth]

First off,I have never owned any vehicle with a carb until I got the boat. I have no problem rebuilding the Qjet if it needs it,I just don't want to do it unneccesarliy(rather go boating).How much throttle do you give em on start up? I usually give it two pumps and leave it at 1/4 throttle for the first start of the day and a half a pump and leave it at 1/4 throttle for subsequent starts where it sits for over 45 minutes.Let it sit at the dock for 30 mins yesterday and it was hard to start.am I doing anything wrong? Hard starts make me nervous.Thanks

 

[achris]

Change your fuel filters first... Then check points, plugs, timing and compressions. Many :facepalm: carbs get 're-built' only to find it was something else causing the problems....

 

[Starcraft5834]

What Chris said...I had a carb problem last year on my 3.0. Needed a good cleaning (chem boil bath) the readjust. ..as for start up..I just put in neutral and turn the key..if I pump it it starts harder.. in real cold conds. Pump maybe. .

 

[Fastatv]

First off,I have never owned any vehicle with a carb until I got the boat. I have no problem rebuilding the Qjet if it needs it,I just don't want to do it unneccesarliy(rather go boating).How much throttle do you give em on start up? I usually give it two pumps and leave it at 1/4 throttle for the first start of the day and a half a pump and leave it at 1/4 throttle for subsequent starts where it sits for over 45 minutes.Let it sit at the dock for 30 mins yesterday and it was hard to start.am I doing anything wrong? Hard starts make me nervous.Thanks

I wouldn't think you would need to prime the engine but once during the day, and that's on the first start up, cold engine. When you give it another pump ( warmed up engine ) , after sitting for 30 minutes, you may be causing a "slightly" flooded condition. Next time your out there, you might try to start it after 30 minutes and don't touch the throttle. Lots of heat builds in the engine compartment of an I/O when the engine is turned off and I think this heat tends to create a slightly rich condition when re-starting the engine. The only carburated engine I never had this problem with was a Scarab I that I had. When I shut the engine down, I would raise the engine cover a few inches to let the heat out.....it really helped on hot start ups. Anyway, I hope I helped in some way.

 

[bspeth]

Points are new,plugs,fuel water sep new ,set timing,coil new,fuel has been treated and mixed with fresh.Guess I will change the fuel filter in the carb.Maybe I just need to get to know her a little better,I don't live on a lake and only get out once a week or so.

 

[Maclin]

I agree with one pump for first start of the day, even after 2 or 3 weeks or more. Then the rest of the day it should start right up with no throttle. Mine will usually start with no pumps within a week or so of the last run. After a month one pump and a little throttle for a few seconds until it is ready to idle, then good to go the rest of that day and the next. Two to three pumps for first start of season if colder weather.

 

[81 Checkmate]

Points are new,plugs,fuel water sep new ,set timing,coil new,fuel has been treated and mixed with fresh.Guess I will change the fuel filter in the carb.Maybe I just need to get to know her a little better,I don't live on a lake and only get out once a week or so.

You said it right threre.....Get to know it alittle better...and if that dont work you may need to do some tinkering with the carb.

 

[Starcraft5834]

water sep filter.....I had one put in this year. did not have one when I bought this boat last year. now with that installed, BIG difference.. start up a snap. One pump and off she goes at first start up....as others have said,, when you warm up these babies they light off at a flick of the key every time.. never need to touch the throttle at start up, when she's warm.......it's often said.. you cant kill a Mercruiser engine..(unless you freezeit, and/or dont maintain it)... they do run very well