Aar0n
Cadet
- Joined
- Mar 24, 2016
- Messages
- 24
4.3 GL-J Spark Plug Gap--.045” or .060”? (and a couple other related questions)
I apologize in advance for the "loaded" post.
I have a 2008 Four Winns H180 with a Volvo Penta 4.3 GL-J. The engine was manufactured in March 2008, according to this sticker on the motor itself:
When I bought the boat this past spring, the previous owner included a handful of new "maintenance parts" (oil filter, fuel filter, spark plugs, etc.) he had, Now that I'm getting to my post-season maintenance, I've used the new filters and am considering putting the new spark plugs in, too. My reasoning is that (a) it couldn't hurt, (b) obviously the previous (and original) owner was planning on doing it soon so it's probably time to do so based on the maintenance schedule, and (c) I noticed the engine tends to have a shake when it's at low RPMs (otherwise runs great). I'm not sure if the shake at low RPMs is normal for this engine or not, so while I know that if it's not normal a number of things could be the culprit (timing, idle speed, idle mixture, etc.), the spark plugs seem like the easiest place to start.
By the way, anyone on here have an opinion on if the shake is normal or not?
OK, so, as you can see, the sticker pictured above says the plug part number is 3851632 and the gap should be .060". However, my owner's manual differs by saying the plug number is 3858997, though it does agree on the .060" gap:
Well, neither of those plugs are what the VolvoPentaStore.com says to use (http://www.volvopentastore.com/Ignit...view_id.780607), though it does say that 21513423 supersedes 3858997. So, according to it, 21513423 is the way to go, and I can find these online. However, they’re of course pretty pricey.
The plugs the previous owner gave me and obviously intended to install are NGK BPR6EFS. I think, according to another thread here on the forum (http://forums.iboats.com/forum/engin...23-spark-plugs), even though it's about a GL-D engine, that these should be OK to replace the Volvo Penta parts outlined above, but there seems to be some disagreement on the gap. Where the sticker on my engine and my owner’s manual both call for a .060” gap (albeit on different plugs than the NGK BPR6EFS), Don S (whose knowledge and expertise I’m in awe of) suggests that all carbureted GLs should be at .045”.
So, if I do go with the NGK BPR6EFS plugs I already have, do you all have any concrete suggestions on what I should gap them at--.045” or .060”?
Also, either way, I am a little worried about the fact that the NGK BPR6EFS plugs come pre-gapped at around .030" (yes, I manually checked the ones I have in my possession) and that extending that to either .045” or .060” is going to put the ground electrodes on a pretty decent angle, making it hard to ensure either measurement (.045” or .060” is where the plugs are truly gapped. This is also discussed in another thread (http://forums.iboats.com/forum/engin...ation-included), which is what got me thinking about it .
Does anyone think this'll actually present a problem, or should I just move forward with the plugs I’ve got gapped at whatever the recommendation here ends up being?
Thanks in advance for any insight and advice you can offer.
I apologize in advance for the "loaded" post.
I have a 2008 Four Winns H180 with a Volvo Penta 4.3 GL-J. The engine was manufactured in March 2008, according to this sticker on the motor itself:
When I bought the boat this past spring, the previous owner included a handful of new "maintenance parts" (oil filter, fuel filter, spark plugs, etc.) he had, Now that I'm getting to my post-season maintenance, I've used the new filters and am considering putting the new spark plugs in, too. My reasoning is that (a) it couldn't hurt, (b) obviously the previous (and original) owner was planning on doing it soon so it's probably time to do so based on the maintenance schedule, and (c) I noticed the engine tends to have a shake when it's at low RPMs (otherwise runs great). I'm not sure if the shake at low RPMs is normal for this engine or not, so while I know that if it's not normal a number of things could be the culprit (timing, idle speed, idle mixture, etc.), the spark plugs seem like the easiest place to start.
By the way, anyone on here have an opinion on if the shake is normal or not?
OK, so, as you can see, the sticker pictured above says the plug part number is 3851632 and the gap should be .060". However, my owner's manual differs by saying the plug number is 3858997, though it does agree on the .060" gap:
Well, neither of those plugs are what the VolvoPentaStore.com says to use (http://www.volvopentastore.com/Ignit...view_id.780607), though it does say that 21513423 supersedes 3858997. So, according to it, 21513423 is the way to go, and I can find these online. However, they’re of course pretty pricey.
The plugs the previous owner gave me and obviously intended to install are NGK BPR6EFS. I think, according to another thread here on the forum (http://forums.iboats.com/forum/engin...23-spark-plugs), even though it's about a GL-D engine, that these should be OK to replace the Volvo Penta parts outlined above, but there seems to be some disagreement on the gap. Where the sticker on my engine and my owner’s manual both call for a .060” gap (albeit on different plugs than the NGK BPR6EFS), Don S (whose knowledge and expertise I’m in awe of) suggests that all carbureted GLs should be at .045”.
So, if I do go with the NGK BPR6EFS plugs I already have, do you all have any concrete suggestions on what I should gap them at--.045” or .060”?
Also, either way, I am a little worried about the fact that the NGK BPR6EFS plugs come pre-gapped at around .030" (yes, I manually checked the ones I have in my possession) and that extending that to either .045” or .060” is going to put the ground electrodes on a pretty decent angle, making it hard to ensure either measurement (.045” or .060” is where the plugs are truly gapped. This is also discussed in another thread (http://forums.iboats.com/forum/engin...ation-included), which is what got me thinking about it .
Does anyone think this'll actually present a problem, or should I just move forward with the plugs I’ve got gapped at whatever the recommendation here ends up being?
Thanks in advance for any insight and advice you can offer.