3.0l Breaking up when warm (cont.)

[Billyd99]

Hi everyone I posted a while ago about a problem I was having. I figured it'd be better to start a new thread rather than revive the old one. Here is a link to the original http://forums.iboats.com/showthread.php?t=477929&highlight=3.0l+breaking+warmhttp://

basicly what happens is sometimes the boat will run great and eventually start sputtering other time it does so right away. It looses power and misses when i give it throttle, it starts and idles perfectly. It has been doing this the whole 3 or 4 years i have owned it. it has a full tune up, new carb, new fuel lines, cleaned the inside of the gas tank, installed a fuel water seperator/ filter, and most recently a new fuel pump. the boat had sat several years before I bought it and fuel gummed things up real bad. For a while I had been getting rusty debris in the screen on the carb which turned out to be coming from the fuel pump. I tried cleaning it out but someone in the previous thread suggested a new one. today I took it out hoping for the best but the new fuel pump didn't help. the only other thoughts I have are that maybe the rusty sandy stuff got into the carb past the screen or maybe that the anti-siphon valve is bad. I would swap the valve out as an easy test but its under the floor and not accessable. I also tested the compression and reset the timing (ive done so much work to it I'm sure I forgot to mention something). I'm really getting sick of this thing, any one have any suggestions???

 

[jamerson62]

Re: 3.0l Breaking up when warm (cont.)

get a new engine! If everything is running good and you replaced all those things, leave me to believe it's really internal in the engine. I would not be surprise to find your pistons are rusted, chamber walls are rusted, something internal in the engine isn't right. If you are getting clean fuel to the carb then fuel isn't the issue it is something else. Maybe even bent rod, mis-shapped cam shaft. Time to decide is it worth ripping the engine out and re-building it, re-machining it, or just flat out replaceing it. Put you in a tough spot. Would make me think hard and long before jumping. Other option is sell the boat to someone new and hope the engine doesn't act out, during the sale phase. Best of luck!

 

[mpdive]

Re: 3.0l Breaking up when warm (cont.)

I would take a real HARD look at the anti siphon valve. The symptoms duplicate a failing valve. Runs about 12.00. Well worth trying.

 

[Billyd99]

Re: 3.0l Breaking up when warm (cont.)

I don't think the engine itself is the problem because compression was decent and sometimes the boat will run perfect with plenty of power. the carb is getting clean fuel but I have a feeling it might not be getting enough, with no load it runs and idles fine but when I put a load on it I start having issues.

I guess the next step would be replacing the anti siphon valve. I will just have to cut a hole in the floor to get at it unfortunately.

 

[Billyd99]

Re: 3.0l Breaking up when warm (cont.)

I was looking online for an anti siphon valve but there are a few different sizes. Is there a certain size i should look for that is standard for a 3.0 or should cut my floor open to just size it up?

 

[Billyd99]

Re: 3.0l Breaking up when warm (cont.)

Alright I cut into the floor but I don't seem to have a valve there. there is the square piece that comes out of the tank and a barbed fitting out the side of it. It looks like it is an anti siphon valve but it is just a hollow aluminum barbed fitting. Could it be possible that at one point it was a valve but the innards have rotten out? or did not all boats have one to begin with? I know its supposed to have a spring and ball bearing inside it but have never seen one to know what it should look like.