Engine Problems with Eldridge McInnis

[shombolly]

This is my new Eldridge Mcinnis Bass boat. The risers went on it and water got into the engine. Replaced the risers the oil many times and checked the compression 125 all cyl's. Before the risers went it was hard to start but once started it ran great esp off idle. I suppect that the poor low speed running was due to the bad risers letting water in. Now that the risers have been replaced it starts right up but I can't get it to go above 2100 rpm's. It starts to cough and sputter no matter how much gas you give it. I would be quick to blame this on bad compression but it all checks out. Help me out guys, this engin only has 400 hours and if i need to replace it i want to do it this winter so i will have a boat to use come spring.
PS fuel filter replaced its got good gas. Points, plugs,wires,cap all replaced

<http://www.imagestation.com/album/?id=2119354191>

[Donn]

Tell us what kind of motor it is.

[shombolly]

Pleasure Craft 351 ford

[shombolly]

The pictures of the boat are on the post before this one.

[Donn]

Whew...I can't imagine retiring a 351 with only 400 hours on it. Find ya a good wrench. Even a rebuild would be cheaper than a replacement. I've got a van with a Cleveland 351/400 in it, and it's a mother of a motor. Just under 200k miles, and one bad cylinder, and she's still cooking just fine. Can't pass emission tests without tweaking, but a great motor.

[shombolly]

Yeah i like ford engins I had a 66 mustang with a 289, great car but i like boat more. My 351 will rev up to whatever under no load. But put it in gear and drive it and it won't go above 2100.

[Donn]

What's your drive? May not be the 351 at all. Could be a bad tranny, eh?

[Ian Marchuk]

When I found myself in similar circumstances, I found it helpful to start from scratch. OK what was disturbed in this last operation? The aluminium watercooled risers I am familiar with all crowd the plug wires fairly hard. It may well be that in the process of changing the risers and/or manifolds that a plug wire or two was damaged. If you can fire this up for a very short interval, say twenty seconds in a very dark area , you may see a light show as spark goes to ground via a flaw in one or more wires. Any wire showing random sparks to ground must be replaced. Next I would look for the similarly simple problem. Could you have mixed up the plug wires?Remove the distributor cap. Check the point gap at full open .025 is a good place to start, check spec and set accordingly. When installing points do so with CLEAN tools and hands as oil and dirt film will cause premature failure. Next, take out the #1 spark plug and with a socket on the crank pulley bring the crank around to TDC on #1. If you can manage to hold a fingertip in the plug hole while you rotate the crank you should feel the pressure as the piston rises in the #1 cylinder. When you are certain that the piston is rising on the compression stroke,continue turning the crank until the pointer on the timing chain cover lines with TDC {0 degree} on the crank. Now you know that you are at TDC compression on #1. Where is the rotor pointing? IT should be to #1 plug wire and points open. From there check the firing order from what it says on the intake manifold. If necessary bump the starter a TINY bit to confirm the rotor rotation, and trace each wire to its respective plug.There is a good chance that two plug wires have been mixed up, it is very easy to do. When you have noodled all this and all is as it should be , carefully put the cap back on straight and true. After all is said and done the final exercise is to check the advance . Connect a timing light up to the battery and #1 plug . If you have a vacuum advance at the distributor, disconnect it and plug the vacuum line to the carb or you will throw off your test because of a vacuum leak. Run the motor at about 750 to 800 RPM. Adjust the distributor to give you about 8 degrees of advance 8 BTDC{before top dead centre}.Be careful here as the timing light wires can get fouled in belts and pulleys while performing this operation to say nothing of fingers.If the distributor is a full mechanical advance job and most marine dist. are in my experience , then there is no vacuum pot on it and of course no vacuum line to remove. In any case, the initial advance is determined in the procedure outlined above with the timing light. After setting the initial advance to 8 degrees BTDC rev the engine to about 3000 RPM and check the full advance should be about 30 degrees but not more than 31 unless you are running 91 or mildly better octane fuel. By the way , we haven't discussed fuel yet. A very little water or dirt in the carb will make it run like a bucket of bolts too. I really have a lot of respect for Racor fuel/water separators, and they are available in smaller capacities for this application . They are so fine that rust and dirt fines and of course water will positively NOT get past the filter .Get the finest micron size 2,3,5? I don't remember, but a supplier will be able to steer you through that choice.
I think that the root of the problem is related to some of the work performed in working on the manifolds?risers but alas , I have been mistaken at least once before.....Try out the procedure outlined above with the KISS principle in mind.... Go from A to Z let me know what you find....Best Wishes.... Ian