4.3l mercruiser alpha timing

[Jg5899]

Ok I am new to the forums and have tired searching with no avail and much confusion. I have a 2007 searay 175 with the 4.3l. Engine serial number OW319696 it also say D.O.M Jan 2005. The distributor cap was replaced and the boat never ran the same. I assume it's off timing. I am extremely confused on the differences between the thunderbolt IV and the V. I don't even know if that's what my engine has. I tried grounding the purple with white and the timing did not move. So I don't know if it wasn't grounded properly or what's going. If anyone can help I would greatly appreciate it! Wanted to get this times and see if the issue is resolved. There's also a black wire going nowhere that has a ring terminal ok the end maybe this is related?

 

[Jg5899]

Re: 4.3l mercruiser alpha timing

Ok looks like I have identified that I have a thunderbolt IV ignition, the ignition module is on the exhaust manifold. Seems odd as I was reading that 98 and up have the thunderbolt V, ill be trying to time it right now and take it out tomorrow and see of performance improves.

 

[Bondo]

Re: 4.3l mercruiser alpha timing

Ok looks like I have identified that I have a thunderbolt IV ignition, the ignition module is on the exhaust manifold. Seems odd as I was reading that 98 and up have the thunderbolt V, ill be trying to time it right now and take it out tomorrow and see of performance improves.

Ayuh,... Welcome Aboard,... You Should have the T-Bolt V, not T-Bolt IV,....

You say this started when ya change the distributor cap,..?? Recheck the Firin' Order,...
Sounds like ya got it Wrong,...

 

[Jg5899]

Re: 4.3l mercruiser alpha timing

Ayuh,... Welcome Aboard,... You Should have the T-Bolt V, not T-Bolt IV,....

You say this started when ya change the distributor cap,..?? Recheck the Firin' Order,...
Sounds like ya got it Wrong,...

Firing order is correct, the boat just seemed to feel a little gutless at WOT. Thanks for your response, I was able to time it last night hopefully ill be able to take it out today and see if it made a difference. Timing was about 5* off.

Idle was a little low after timing was done ill probably have to adjust it once I get it out on the water.

I'll also post pictures to confirm that it's a thunderbolt IV.