Mercruiser 888 Won't Run, Any ideas?

[RogersJetboat454]

Re: Mercruiser 888 Won't Run, Any ideas?

Which firing order was used when putting this back together?
302, or 351?

 

[jjohanson]

Re: Mercruiser 888 Won't Run, Any ideas?

I know changing to electronic ignotion will not fix the problem, like i said my next day off i will be switching it to 10 degrees BTDC and checking the firing order. When removed i just labeled the plugs but i know the firing order is in the manual i have and i will be checking this also. In my first post, i said i would also like to switch to electronic ignition i never said i thought this was the problems im just wanting to upgrade for reliability.

 

[jjohanson]

Re: Mercruiser 888 Won't Run, Any ideas?

Ok timing has been changed from 6 degrees to 10 degrees BTDC and the firing order was checked. My manual says 1-3-7-2-6-5-4-8 and the firing order I got is correct. After cranking on it over and over I was able to get it to fire up one time and it ran for a couple seconds and then died. I replaced the condensor and checked for spark. Am I suppose to only have 4.5v at the coil?

 

[cecho]

Re: Mercruiser 888 Won't Run, Any ideas?

4.5v is too low. I believe 7 to 9 is normal after the resistor. Put 12 volts directly from the battery to the coil and see if it runs. You won't hurt the points or coil if you do it for a short while.

Also, are you sure you are getting fuel?


You only need 3 things for an engine to run. Fuel(Gasoline), Air(Compression), Heat(Spark). You're missing one of them.


Edit: I don't think you can actually set the timing unless it's idling. I've noticed engine timing seems to move a lot while cranking... might just be my timing light though. It's old and cheap.

 

[jjohanson]

Re: Mercruiser 888 Won't Run, Any ideas?

Yes im sure im getting fuel i can smell it flood and when i pull the plug out it has fuel on it. Also sure i got spark, if strong enough i dont know. I looked up a replacement coil and the one on the boat looks different then the one i have. Ill try what u said next time i get the chance and let u know.

 

[RogersJetboat454]

Re: Mercruiser 888 Won't Run, Any ideas?

Ok timing has been changed from 6 degrees to 10 degrees BTDC and the firing order was checked. My manual says 1-3-7-2-6-5-4-8 and the firing order I got is correct. After cranking on it over and over I was able to get it to fire up one time and it ran for a couple seconds and then died. I replaced the condensor and checked for spark. Am I suppose to only have 4.5v at the coil?

Which manual are you using? Factory, Seloc, Clymer, or something else?
The 1-3-7-2-6-5-4-8 firing order is known as the 351 Windsor firing order. It promotes better loading of the crankshaft, and was probably used on the 888 engine originally.

The only thing I question is given the age of the engine, is there a possibility that someone may have swapped in a different cam shaft (say during a rebuild) that used the older style firing order?
The older 260/289/302 firing order is 1-5-4-2-6-3-7-8

When you got it running for a few seconds, did it sound like it was hitting on most cylinders, or was it running pretty rough?

 

[jjohanson]

Re: Mercruiser 888 Won't Run, Any ideas?

It was running rough, but the first day i had the boat it ran perfect for couple hours. Then second time i took it out it broke down. This was right at the end of summer so i winterized and left till next summer. I know this wont fix the issue, but the pertronix ignitor ii and flame thrower ii epoxy are on the way.

 

[haulnazz15]

Re: Mercruiser 888 Won't Run, Any ideas?

Just to make sure you have it right, here's a link to the Ford engine/dizzy layout. The firing order could be different, but this diagram still shows the correct rotation of the distributor so that you get your plugs in the correct order on the distributor cap. I'm a Ford guy, and I still forgot about the counter-clockwise rotation when I first wired up my rebuilt 351w. As long as you have #1 cylinder at TDC on the compression stroke, and the rotor pointed at the #1 cylinder post, you will be close enough on timing to allow it to start. It's difficult to set timing on a non-idling engine, as the RPM's need to be at a consistent 650-700rpms.

http://www.allfordmustangs.com/foru...-knows-351w-firing-order-zfiringorder-5.0.jpg

Also, you should have more voltage than that at the coil with the key on, but not starting (approx 7-8volts). When you are in the start position with the engine cranking, you should get a full 12V at the coil.

Edit: I just saw your post about the Pertronix set up on the way . . . for this, you will need to BYPASS the the (tan, i think) ballast resistor wire. The easiest way to do this is to wire a jumper from the electric choke positive (12V) to the positive of the coil. The Pertronix units need 12V all of the time.

 

[jjohanson]

Re: Mercruiser 888 Won't Run, Any ideas?

Im using the owners manual that came with the boat.

 

[jjohanson]

Re: Mercruiser 888 Won't Run, Any ideas?

The firing order is set for the correct rotation i also double checked that. Thanks for the help so far guys i appreciate it. I will try to run that wire from battery to coil today just to test if thats the issue

 

[jjohanson]

Re: Mercruiser 888 Won't Run, Any ideas?

I ran the 12v wire from the battery to the coil and still nothing. I reset the timing and checked the firing order again also.

 

[cecho]

Re: Mercruiser 888 Won't Run, Any ideas?

If your timing light is lighting up than you are getting a spark. It sounds like a fuel problem to me right now. People will probably scoff the idea, but I'd try some starting fluid. Here's what I'd do:


1. Check the timing light on other spark plug wires to make sure not only #1 is firing.
2. Try starting it with Full throttle to make sure it isn't flooded.
3. Try starting it with gasoline down carb to see if it's getting fuel or not.
4. Try starting it with starting fluid.
5. Check compression on all cylinders.