5.7 Mercruiser Thunderbolt V What is the Timing at 5000 ft Elevation ?

[lightman32]

5.7 Mercruiser 350 mag ski Thunderbolt V Timing at 5000 ft Elevation

I understand setting the igniyion system to base mode by grounding the purple and white wire. And I have set my timing to 10 d btdc as specified . The boat runs great . I know on cars the timing must be slightly retarded for elevation , is this necessary on the boat ? If so how much ? Thank you in advance .

 

[Bondo]

Re: 5.7 Mercruiser Thunderbolt V What is the Timing at 5000 ft Elevation ?

Ayuh,... I don't know,... But,.. If so,.. The T-Bolt V will do it for you...

 

[lightman32]

Re: 5.7 Mercruiser Thunderbolt V What is the Timing at 5000 ft Elevation ?

That must be why I haven't noticed any issues . Thanks for the quick response.

 

[soaringhiggy]

Re: 5.7 Mercruiser Thunderbolt V What is the Timing at 5000 ft Elevation ?

does the t-bolt four do the same?

 

[Don S]

Re: 5.7 Mercruiser Thunderbolt V What is the Timing at 5000 ft Elevation ?

Nope, no knock sensor.

 

[soaringhiggy]

Re: 5.7 Mercruiser Thunderbolt V What is the Timing at 5000 ft Elevation ?

hmm...

Ok thanks,

Is there a reason or the ability in other ways to reset the t-bolt?

I really am not up on the ecm. (Old, point/mag kinds guy)

 

[Bondo]

Re: 5.7 Mercruiser Thunderbolt V What is the Timing at 5000 ft Elevation ?

Is there a reason or the ability in other ways to reset the t-bolt?

Ayuh,... What's That mean,..??

You can set the timing on the T-bolt IV, or the T-Bolt V....

Neither are ECMs,... They're Electronic Igntion systems...

 

[Don S]

Re: 5.7 Mercruiser Thunderbolt V What is the Timing at 5000 ft Elevation ?

With a Thunderbolt V system, you do have to put it into base timing mode for setting the timing and adjusting the idle mixture.
Might want to head up to the Adults only sticky and download a service manual for your engine. Details for putting it into base timing and setting it are described in detail with pictures.

 

[soaringhiggy]

Re: 5.7 Mercruiser Thunderbolt V What is the Timing at 5000 ft Elevation ?

Thanks,

I have already got them, I have not read all of it yet, but I will do that.

 

[soaringhiggy]

Re: 5.7 Mercruiser Thunderbolt V What is the Timing at 5000 ft Elevation ?

Ayuh,... What's That mean,..??

You can set the timing on the T-bolt IV, or the T-Bolt V....

Neither are ECMs,... They're Electronic Igntion systems...

ok ignition.

What I was asking was, at high elevation, is there a reason to reset a t bolt IV. I am not getting any knock that I can hear.

It was stated that a V will do this by its self, however, the IV does not have a sensor.

OK, my question was mearly would it be a good idea to reset mine as it has gone from sea level or thereabouts and now lives at 4500 feet.

 

[Don S]

Re: 5.7 Mercruiser Thunderbolt V What is the Timing at 5000 ft Elevation ?

OK, my question was mearly would it be a good idea to reset mine as it has gone from sea level or thereabouts and now lives at 4500 feet.

soaring, best thing you could do is start a new thread, don't hijack lighmans post regarding a TB5 ignition with your questions about your TB4
It just gets way to confusing with 2 different subjects going in one thread. You soon have no idea who is replying to whom

 

[soaringhiggy]

Re: 5.7 Mercruiser Thunderbolt V What is the Timing at 5000 ft Elevation ?

soaring, best thing you could do is start a new thread, don't hijack lighmans post regarding a TB5 ignition with your questions about your TB4
It just gets way to confusing with 2 different subjects going in one thread. You soon have no idea who is replying to whom

ok,

 

[dan t.]

Re: 5.7 Mercruiser Thunderbolt V What is the Timing at 5000 ft Elevation ?

why would you want to reset the timing for higher altitude? a carb gets richer as altitude increases,the most you would want to do is rejet slightly leaner