Merc 5.7 ignition probs

[str8down]

Re: Merc 5.7 ignition probs

Figured it out. Pulled all the new plugs out to regap them, just to make sure it was good, and one of them had a cracked ceramic. put a new plug in there, and it ran great. Thanks for all of your suggestions though.<br /><br />One more thing though, when I pulled the plugs, they were all off gapped. i gapped them all at .035 and when I pulled them to regap them, they were all at like .028. Seems strange.

 

[prockvoan]

Re: Merc 5.7 ignition probs

What plugs are you using?

 

[str8down]

Re: Merc 5.7 ignition probs

NGK

 

[Don S]

Re: Merc 5.7 ignition probs

I don't know how to set timing, but I am very mechanical. Can anyone easily tell me how?

Do you have a manual? They usually show you.<br />But, before you set timing, you have to set the point dwell with a dwell meter. Then you use a timing light hooked to #1 sparkplug wire and check the timing marks on the front of the engine.<br />Turn the distributor till the proper mark is aligned.

 

[Fishermark]

Re: Merc 5.7 ignition probs

Hi Don,<br />If you read the whole post you will note that he doesn't have points, he apparently has electronic ignition. Not sure what type - Thunderbolt IV? V?

 

[Don S]

Re: Merc 5.7 ignition probs

Yea, I missed that, I read this at the top and kind of skimmed the rest.<br /><br />

Originally posted by str8down:<br /> It's a points ignition. I changed the distributor cap and rotor.

Without a manual, he's not "Mechanical" enough to be messing with it.

 

[str8down]

Re: Merc 5.7 ignition probs

It's a TB V and I just bought the repair manual. Haven't looked through it though. Can anyone give me a breif synopsis on setting timing.

 

[Sagabu]

Re: Merc 5.7 ignition probs

I use a vacume gauge and set everything (carb/distributor/timing) to maximum vacume. Works great for worn or modified engines.<br /> If you have a vacume advance, disconect/plug it first and idle the engine to 1200 rpm.<br /> Idle back down after max vac is achieved.<br /> This is how I do it .