88 3.0- running terrible... help

[Suprathepeg]

I am a total newb when it comes to carb engines and boat engines.

THe boat ran really nice a month ago before I had the floor replaced and did a bunch of work to the interior.

I splashed it today and tried to fire it up but it ran like crap.

It will only start with a lot of throttle and won't hold idle without a lot of throttle. If I put it in gear it won't get up to speed to move the boat at more than a quick idle. Its making a nasty popping sound I think might be back firing.

Any ideas where to look first?

 

[achris]

Start with the basics. Check all the spark plug wires are on, and on the right places. Check for obvious things like bits of gasket poking out where they shouldn't. Next pull the plugs (and look at them) and do a compression test. Check the points faces and the points gap. Look at the inside of the distributor cap and the rotor. Then check spark quality, and timing. If that all looks good, move to the fuel system. Check/change filters, check for vacuum leaks, check the anti-siphon valve, make sure the choke starts close, then opens properly.

Chris......

 

[Suprathepeg]

No Title

Ok so it's raining today and I'll be off and on with it.

First off I checked the plug wires and the cap and rotor. Distributer isn't loose, rotor and cap are brand new. There are two things with the cap. Firstly one of the screws was loose, secondly I found this felt thing floating inside. Also the rotor was loose on the spindle. Could this be the cause?

 

[Alumarine]

The felt thing goes in the shaft under the rotor.
Put a few drops of oil on it. It's to lubricate where the points rub I believe.
The rotor shouldn't be loose.

 

[Bondo]

Ayuh,.... Sounds like a fuel delivery issue to me,....

 

[Suprathepeg]

Ayuh,.... Sounds like a fuel delivery issue to me,....

That's what I was thinking. It smelled a bit rich.

Look at this http://youtu.be/56gYvYRXBa0

 

[Suprathepeg]

A friend suggested I disable the choke. This a good idea?

 

[achris]

A friend suggested I disable the choke. This a good idea?

No. Set it up right and continue to use it. Engines are difficult to stay cold without choke.

 

[Suprathepeg]

How do I do that? How do I test it.

 

[achris]

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[Suprathepeg]

So I broke down and took it to a mechanic and he did a full tune-up of everything from the valves to the timing. It purrs like a kitten now. He does think that the choke is pooched, so he disabled it. I'll start hunting for a new choke but it fires up and idles fine without it for now. Best $100 I've ever spent. This week I"ll install a new bilge pump and a new blower and I think it's water time this weekend!

 

[Suprathepeg]

Ok so it happened again. Looked under the valve cover and the rockers are loose. Is there a typical reason for the nuts to be coming loose?

 

[achris]

Are you sure the nuts are coming loose, and not the studs pulling out of the head?

Chris.....

 

[Eric 3.7LX Alpha 1]

If the stud hasn't moved... I have seen loose rocker nuts once before in a car.

They're locking nuts like what holds the drive to the bellhousing. Just like the drive mounting nuts, they can get worn out.

You could reset it and mark it with a sharpie see if it moves, or just get a new one.

It could also be the cam lobe going flat, hopefull not.

Would have to drain the oil and check for metal in it.

 

[Suprathepeg]

I'm gonna check it out and let you guys know. Thanks for the places to look.

 

[Suprathepeg]

Are these nuts basically lock nuts? I can spin the two under the oil filler with my finger in the hole. Should they be difficult to turn like a nylock?

 

[Suprathepeg]

I'm having trouble finding these nuts anywhere local. Can I use something that is not a merchant part number?

 

[flipbro]

If you want to rule out a bad cam lobe mark each push rod with a marker. Then crank engine over with starter.watch the push rods should turn. If they dont you have a bad lob. As for using a different nut I guess if its a lock nut with the same thread you would likely get away with it..

 

[flyman219]

The rotor needs to be tight on the shaft, if not your timing will not be consistent this will make your motor run bad at best. On my 2007 3.0 there is a small metal insert that goes in the key slot of the rotor to snug up the rotor. yours may have used the felt block, you'll need to check a manual to figure your year out.

Mike

 

[Suprathepeg]

Good news and bad. The good news is that the problems was the nuts and we got that sorted. The bad is that we blew a head gasket. So this week is headgasket :-(.