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Thunderbolt V Ignitition
I know the Thunderbolt IV systems seem to be somewhat desirable in the used market. How about the Thunderbolt V's?
I have two from my merc 600SC's.. with the knock sensors. Any one have any thoughts on what they might be worth in the used market? Only real downside as I see it, is the Rev Limiter set too low... |
nice thing about T-bolt 4. rev limiter is when the rods leave the oil pan. but then, everything has a downside...
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What are those set at 5,250?
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Originally Posted by getrdunn
(Post 4283370)
What are those set at 5,250?
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Just an FYI here as writing about T bolt V ignition is a lot different than T bolt IV by far overall and in general not just one specific app is the exact same using TB V ignition system. The general standard info applies here for TB V ignition systems.
The over speed control / rev limiter comes in per app 100 to 150 RPMs from the max rpm DEPENDING on the engine. For example lets say a carb TB V app - 5.7 LX 350 recommended rpm range is 4400 - 4800 so rev limiter would come in at 4950 dropping spark. This goes PER - APP for the rev limiter/ over speed control. The TB V ignition system uses the same distributor as the TB IV but the TB V has an ignition control module and DESA = digital Electronic Spark Advance. Also TB V has a knock control Module as well. TB IV had non of this. FYI. next TB V has to be set into BASE TIMING MOOD for setting the ignition timing and here is a lot people and a lot of marine tech's do not even know this part of it. To set proper idle speed / idle mixture , the boat needs to be on the water and the ignition set into BASE TIMING MOOD to make PROPER idle speed / idle mixture adjustments CORRECTLY. I can not tell you how many do not know this including marine techs as well. Also another reason why people do not know about setting the ignition (TB V) into base timing mood is because the idle speed control feature exists in the ignition control module. TB IV does not share any of this nor the feature of TB V. TB V ignition has 5 spark control features. Idle speed spark control Acceleration Spark Advance MBTSA = Mean best timing spark advance or MBT = Mean Best timing however one likes to call it Rev limiter or over speed control however one likes to call it. Knock retard spark control Also troubleshooting TB V compared to TB IV there is a lot more to it than your standard chart testing as both will apply but because of the added features of TB V many more steps involved. TB V ignition system used on Mercruiser V-6 and up thru out their model line ups. just saying I wanted this writing as well for my own info so I do not have to think about all the differences in my head again . Anyways hopefully good info for whomever. more to come, to much to write all of this tonite. |
Originally Posted by getrdunn
(Post 4283370)
What are those set at 5,250?
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Originally Posted by BUP
(Post 4283487)
Just an FYI here as writing about T bolt V ignition is a lot different than T bolt IV by far overall and in general not just one specific app is the exact same using TB V ignition system. The general standard info applies here for TB V ignition systems.
The over speed control / rev limiter comes in per app 100 to 150 RPMs from the max rpm DEPENDING on the engine. For example lets say a carb TB V app - 5.7 LX 350 recommended rpm range is 4400 - 4800 so rev limiter would come in at 4950 dropping spark. This goes PER - APP for the rev limiter/ over speed control. The TB V ignition system uses the same distributor as the TB IV but the TB V has an ignition control module and DESA = digital Electronic Spark Advance. Also TB V has a knock control Module as well. TB IV had non of this. FYI. next TB V has to be set into BASE TIMING MOOD for setting the ignition timing and here is a lot people and a lot of marine tech's do not even know this part of it. To set proper idle speed / idle mixture , the boat needs to be on the water and the ignition set into BASE TIMING MOOD to make PROPER idle speed / idle mixture adjustments CORRECTLY. I can not tell you how many do not know this including marine techs as well. Also another reason why people do not know about setting the ignition (TB V) into base timing mood is because the idle speed control feature exists in the ignition control module. TB IV does not share any of this nor the feature of TB V. TB V ignition has 5 spark control features. Idle speed spark control Acceleration Spark Advance MBTSA = Mean best timing spark advance or MBT = Mean Best timing however one likes to call it Rev limiter or over speed control however one likes to call it. Knock retard spark control Also troubleshooting TB V compared to TB IV there is a lot more to it than your standard chart testing as both will apply but because of the added features of TB V many more steps involved. TB V ignition system used on Mercruiser V-6 and up thru out their model line ups. just saying I wanted this writing as well for my own info so I do not have to think about all the differences in my head again . Anyways hopefully good info for whomever. more to come, to much to write all of this tonite. That's some great info BUP... Sounds like they are worth a lot more then the IV... LOL I've never heard of putting them into Base Timing Mood... Is this typo? Should it be mode? or is MOOD correct? Also how do you get it into base timing mood/mode. I've always just set total timing around 29 degrees and let it be.. I've never had an issue doing this. and the motors run strong. I do have some blower surge at an idle. |
3 Attachment(s)
Hope this helps
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Originally Posted by MILD THUNDER
(Post 4283586)
Hope this helps
Thanks Joe.... I wonder where the timing ends up at WOT higher RPM setting timing based on this doc... As mentioned I always just set total timing at 3500 with no load.. Never grounded that Purple and white wire... I always wondered what it was there for... I never even looked to see where the base timing ended up... LOL Wonder if I've been lucky? Overworking my knock sensor? or extremely on the safe side? |
YES TYPO ON MY PART Should be MODE. not mood
Really not a typo I AM JUST A PLAIN OLD BAD SPELLER AT TIMES My mind works faster than I can type. |
MT - Joe thanks for posting those pages because now I do not have to type out what all the spark advances are and proper way to set base timing mode (spelling correct).
Its amazing that you found that and posted it. The pages you posted look to be from the OEM Service manual or the Mercruiser training manual from way back. I will have to read the pages and make sure I was correct about everything that I posted. |
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