tired of rebuilding my carb and no results

[CAPTKEV85]

Since i Bought my 1985 sea ray seville 25 foot with mercruiser 260 I have had carb issues. I rebuilt it my self last year and it still boggs when you floor it from a idle. Once it hits around 2700 rpms it has power and goes. I am going to buy a new carb. Now one question is in my head. My boat when it planes off really leans back on an angle. Could the carb be running out of fuel in the bowl? is there a wedge made for problems like this? any info would be great thanks.

 

[Don S]

Re: tired of rebuilding my carb and no results

Some carbs just can't be rebuilt. I probably averaged about 50% over the years. Started getting better once we purchased an ultra sonic cleaner with the proper chemicals, but that's not in most peoples budget.
At that point, you replace with a new carb. I find the remans (Especially from Mercruiser) have about a 10% or LESS success rate. Better from real carb rebuild shops, not your local boat shop, but specialty carb shops. But even some of their rebuilds fail.

 

[CharlieB]

Re: tired of rebuilding my carb and no results

Check for 'play' in the primary throttle shaft, once the base plate is worn and the shaft starts getting sloppy it is next to impossible to get a decent idle mixture with all the air that leaks in thru the sloppy fitting shaft.

There are a few carb shops that can install bushings to reseal this and restore idle control, this is a lot more cost effective than ordering a new carb.

 

[tpenfield]

Re: tired of rebuilding my carb and no results

Since i Bought my 1985 sea ray seville 25 foot with mercruiser 260 I have had carb issues. I rebuilt it my self last year and it still boggs when you floor it from a idle. Once it hits around 2700 rpms it has power and goes. I am going to buy a new carb. Now one question is in my head. My boat when it planes off really leans back on an angle. Could the carb be running out of fuel in the bowl? is there a wedge made for problems like this? any info would be great thanks.

You may not actually have carb issues - based on your description - but it may be worth getting a new one anyway.

A 260 engine may struggle a bit to get a 25 foot boat out of the water. The planing issue that you mention may be one of outdrive trim or improper weight distribution. This will relate back to the 'bogging' issue when accelerating.

 

[Silvertip]

Re: tired of rebuilding my carb and no results

Try this: When getting out of the hole rather than hammeriing the throttle, bring it up gradually. If the engine seems to behave very differently than when you hammer the throttle, you have an accelerator pump issue. It is either being installed incorrectly or it is simply not working properly. It this is a two barrel rochester you need to pull the "power valve" and make sure that is working properly. If this is a four barrel Q-jet you may have a misadjusted secondary throttle spring. If that adjustment or the spring itself is weak then the secondaries open way too early which they shouldn't. These are "air valves" and have no physical connection to the primary linkages. This will cause the engine to bog badly until the RPM gets well into the rev range.

 

[CAPTKEV85]

Re: tired of rebuilding my carb and no results

Well everyone is hitting points of what my carb is doing. I did notice last year silvertip that when i hammered on the throttle and let off alittle the boat came alive even more then floored. I never messed with the secondary springs at all. Also this carb seems very worn as per bushings on the primaries and i have days were the boat will idle great at 550 rpms and days it runs like crap. Also idle mixture screws really do not change much when adjusted at 550rpm. Also I have a new coil, cap rotor, plugs, wires, and fuel filters. So the boat is tuned up but this carb is the problem. As per planning issue. It planes fine but i was trying to say i guess is when the boat is planning can the carb run out of fuel? do people use wedges to eliminate this problem?

 

[LilRedNeckGirl]

Re: tired of rebuilding my carb and no results

Ok, calm down, listen and learn. Your running a 1985 model year. Back then there was no ethanol in the fuel. I had the same problem with my 1985, and beat my head against the wall, UNTIL, my mechanic bored out the jets. Its that simple, just run a slightly larger hole into the existing jet holes, and let in a lil bit more fuel wnen you throttle up. If you running good at the idle, running good at wot, running good anywhere in between, and only get the bog out when you hammer it, chances are its starving for fuel because those jets are too small for ethanol gas and the lower octane fuels of today.
Here's the bottom line. Try it. if it dont work, go buy the new carb, @ nothing to lose, but savings can be te cost of the new carb.
This lil trick saved me from replacing my carbs on twin 140's. It works, its easy, its cheap to do.
I Found the old post, remember, these are for a 140 hp 3.0 carb, if yours is different, think before you drill.
", Drilling out the accelerator pump ports helped 100%. On the weekend, not 1 issue of stalling on fast starts. . The ports were drilled out to 1/16th . my mechanic did the modification, recommended by mercruiser tech support, so not sure what is involved. You might google " Ace Marine" in Stuarts draft virginia and speak to the mechanic or go directly to mercruiser carb tech support for questions..."

 

[CAPTKEV85]

Re: tired of rebuilding my carb and no results

The jets are slightly bigger. I tried it last year when I rebuit it. I did notice that when I adjusted the float it ran better. I adjusted it to allow more fuel in the bowl. But my idle issues have it's days. Somedays it's fine and somedays I have to bump it up so it does not run rough. I was also looking into the marine edlebrock carb. Any opinions on this carb?

 

[LilRedNeckGirl]

Re: tired of rebuilding my carb and no results

No opinions or experiance with other carbs. Just know what we did to solve and understand our issue. our engines were starving so we gave them more fuel. I do know, my husband loves the Edlebrock carbs on his cars, if that helps.

 

[Scott Danforth]

Re: tired of rebuilding my carb and no results

just my observations.

prior to drilling jets, I would put in some ethanol free fuel and try that.

if adjusting the float helped, then yes, your float is not adjusted properly, or the float may be saturated.

idle speeds may change slightly with weather. at least it did on my 2002 mercruiser.