mercruiser 3.0 backfiring and running bad

[cbucner]

Re: mercruiser 3.0 backfiring and running bad

Just my 2 cents , You say to adjust the idle mixture , I did it like the service manual says, but my question is what does it have to do the idle mixture with the top end running conditions??The boat idles fine is the 2300rpm up that is causing the problem and I checked the advance and it advances like it should be .
Just asking??
Thanks
And again like I said the boat runs perfect even top end for a few trips up and down the river, if I stop it then it goes downhill. So that's what drives me nuts, how come you run perfect now and after a stop that's it???
If there was an adjustment or anything else it would not run since the start !!!

 

[cbucner]

Re: mercruiser 3.0 backfiring and running bad

Here we go!
I finally took out the bottom part of the drive to get to the water pick up impeller.
First I found a problem with the rubber seal on the shaft which I guess has to be on the cover of the impeller and seal the water from coming out , and mine was out on the shaft somewhere so the water could escape from the impeller housing
Next here the shots of the day starting with the drive and the condition of the impeller and the housing .
Please advise
THanks

http://64.65.22.75/boatservice/1.jpg

http://64.65.22.75/boatservice/2.jpg

http://64.65.22.75/boatservice/3.jpg

http://64.65.22.75/boatservice/4.jpg

http://64.65.22.75/boatservice/5.jpg


I'll appreciate any replies
Thanks

 

[cbucner]

Re: mercruiser 3.0 backfiring and running bad

Where can I get bigger jets for my carb?/
THanks

 

[cbucner]

Re: mercruiser 3.0 backfiring and running bad

Hey Don , I have the engine service manual no 26 and the drive manual no 14.
I was reading about the power valve and what it does.
I still need help solving the problem though
THanks

 

[enn858]

Re: mercruiser 3.0 backfiring and running bad

That impeller is Shot

It*`s hard to see on your pictures if the pump housing is shot too - but i would get a water pump repair kit like this:

http://cgi.ebay.com/ebaymotors/ws/e...E:B:EOIBSAA:US:11&viewitem=&item=160042392920

The rubber seal is not your problem - Don has recently made an excelent posting about this seal - try if you can find it - it was great.

 

[fcveazey]

Re: mercruiser 3.0 backfiring and running bad

vapor lock?? http://www.boatfix.com/merc/Bullet/99/99_07.pdf

 

[vinny957]

I have a 1988 cheetah Ski boat It was running great When I was on the water when I headed back to put it on the trailer it died in the middle The Lake it is back firing through Exhaust out the middle of the prop I cannot figure out what is causing this it wasn't doing it at all but on the way back in I heard one loud Bang and i shut the boat off immediately. Now when I try to start it it just pops every 3 or 4 turns It only does this when I try to give it a little gas to get it to start if I try to cold start it does not do this

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