mcm470 hard to turn over

[charlescox]

hi guys,<br />i have a 1982 470 that has had this problem ever since i owned it. It cranks and runs fine. This year the temp has been about 185 which seems a little high. When you run around a little while and then shut off the engine it only turns maybee a half of a turn or less. it sounds as though the batteries are dead. I have replaced the cables, had starter worked on , new brushes and bushings. still same problem. Last year it would help if we idled it down for a while before turnning off. My questions is is this still likely a starter problem , could it be getting too hot, or a timming issue. thanks

 

[lenny2113]

Re: mcm470 hard to turn over

charlescox, <br />To be on the safe side I would make sure you have no water in your engine. The simptoms you describe MAY BE an indication of engine hydrolock. Pull spark plugs out and see the condition of plugs. If plugs are rusted, then you're getting water into your cylinder(s).<br />When was the manifold and riser last changed?<br />If you're boating in salt water your riser/manifold life is 3-4 years. Also check if your oil has water in it. Pull dipstick and if oil is milky color, it has water in it.<br />Post back on what you find.

 

[charlescox]

Re: mcm470 hard to turn over

just changed the plugs, old ones did not seem rusted. i still have them and will check them for rust tonight. I have never changed the risers I am in fresh water. thanks you for the help. What is this hydrolock that you talk of?

 

[Limited-Time]

Re: mcm470 hard to turn over

Yes it could be a timing issue. Verify the initial timing is correct then check the advance to see if it's working properly.

 

[charlescox]

Re: mcm470 hard to turn over

could you please explain how the timming advance works, and how to check? how does the timming create a problem like this? Could i verify by removing the plugs when this happens and trying to turn over?

 

[lenny2113]

Re: mcm470 hard to turn over

What is this hydrolock that you talk of?

Water enters into combusting chamber and seizes pistons. "hydrolocked" = "waterlocked"<br />As I said it is just a possibility. <br />Blown head gasket would allow water into cylinder. If the engine ran hot for a prolonged time head gasket could burn out. The overheating could be originated by a blocked water passage in the exhaust manifolds and (or) risers. Another cause, which is more frequent is a raw water pump rubber impeller in your outdrive.<br /><br />I do not know if the timing issue would have the same simptoms as if it is hard to turn over.<br />You need a timing gun to properly adjust timing. <br />If you suspect that your timing may be off, it should be corrected regardless. Even if timing is not the cause of your problem, it should be within the manual specs.

 

[jfc092]

Re: mcm470 hard to turn over

charles;<br />470 mercs are known to be slow starters. I have the same problem with my 1978 470. I did all the checks, replaced cables, checked timing etc.<br />The solution I found was to make sure your starting battery is a very high rated CCA (cold cranking amps) I believe mine is around 900 CCA.<br />A low rated battery will not work very well.

 

[bowhuntrrl]

Re: mcm470 hard to turn over

Replace all your battery cables with 0(ought) or 00 (double ought) cable. You may have to go to a place that services 18 wheelers to get it, but it's worth it. The fat cable reduces the voltage drop to the starter. Also try to keep your battery cable to the starter as short as possible. This has fixed many 470's with the same problem.

 

[Wotknot]

Re: mcm470 hard to turn over

470's are a high compression puppy. As suggested, a high CCA battery along with 1/0 or 2/0 cable helps supply the juice it needs. BTW, you can get that awg cable at most any reputable welding supply company.

 

[xltier]

Re: mcm470 hard to turn over

would be good if you could find a d.c amp probe to put on your batt. cable during cranking to see what the starter is drawing for current.your battery should maintain 9-10 volts while cranking also.u can check that with a volt meter.