mercruiser 5.7 ping

[ocjonny]

Hi guys, I am trying to get an answer for pinging on my engine. My boat is a '97 Crownline 202BR with a 5.7 merc., 2 barrel carb. Thunderbolt IV ignition. The valve seat broke. Engine was completely rebuilt. It was bored .030 over and had block and heads decked. I also added an aftermarket heat exchanger. Engine runs great until it heats up. Then, at full throttle, it begins to ping after a minute or two. I have to slow to get pinging to stop.<br /><br />Can this be from the heat(engine temp at 195 during full throttle) or timing of engine? Can the electronic advance module be bad, and causing improper advance? Guy at local mercruiser dealer said he never heard of the module on the distributor(chip for electronic advance) going bad. Any thoughts?

 

[bigbrownbuku]

Re: mercruiser 5.7 ping

195 is high for temp, have that problem fixed. how is your boat propped, what kind of wot rpm can you achieve with a normal load? has the timing been set correctly?<br />jb is likely going to move this post

 

[JB]

Re: mercruiser 5.7 ping

http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=17;t=040053 <br /><br />Mercruiser topic.

 

[Don S]

Re: mercruiser 5.7 ping

Check for advance with a timing light, then you will know for sure if you have the proper advance or not. <br />And to answer your question, Yes, the module controls the advance.

 

[Bondo]

Re: mercruiser 5.7 ping

Also Check the Carb.,+ Fuel Delivery,............<br /><br />A Lean condition at WOT will cause Detonation,....... Especially if the Timing is set alittle on the Adv. side,.........<br />You could be jetted Lean with the increased compression from the decking,.....<br /><br />In My experience,... The T-Bolt IV either Works,.... Or it Don't.........

 

[prockvoan]

Re: mercruiser 5.7 ping

Sounds lean to me.I wouldn't run it till you check the timing or carb fuel flow or you will be rebuilding the engine again very soon.