boater2065
Active Member
I gave it a tune up in October 2020. Replaced plugs, replaced cap and rotor, changed oil and replaced oil filter.
The plugs I am using are NGK BPR6EFS which I have read are spec'd for this engine.
Sheen in water
- Thread starter boater2065
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I gave it a tune up in October 2020. Replaced plugs, replaced cap and rotor, changed oil and replaced oil filter.
The plugs I am using are NGK BPR6EFS which I have read are spec'd for this engine.
sbw1
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I looked at your pic of the plugs. They look like they have been "wet" from gas flooding them and not burning off completely. Do you spend a lot of time at low RPMs due to no wake zones? Is the air filter clean? You may try using a hotter plug. Those engines do best running at 3000 to 3100 RPMs. You said the plugs are 10 months old. How many hours?
boater2065
Active Member
When I pulled those plugs in October they had about 50-60 hours on them. RPMs on those hours were about 75% low RPMs. Would they have extra build up on them because of the throttle body issue, of spraying too much fuel?
sbw1
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I don't know the answer to your question. 75% low RPMs could very well explain the dirty plugs. Plugs have gotten better over the years. Next time you change them, look into using a hotter plug if you are running low RPMs for your normal use. Would also buy the Platinum tip plugs. They are worth the extra money. I wouldn't worry too much about your engines because they are throwing off a little gasoline at start up. The time to worry is when they do that and you smell strong gas odors.
boater2065
Active Member
Appreciate the advice. I'll look into hotter plugs with platinum tips next time to see if that is better. We'll see how it performs now that the throttle body has been rebuilt. I wasn't able to take it for a spin, only let it run in the boathouse up to temp, and the fuel smell seemed to go away once the engine was up to temp. Fingers crossed
scoflaw
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You shouldn't need anything hotter or more expensive.
Iridium and platinum make the plugs last longer which isn't your problem.
Iridium and platinum make the plugs last longer which isn't your problem.
sbw1
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Google "read spark plug colors-Champion Auto Parts"
It mentions trying hotter plugs for engines run at low speeds, and which also look like the pix he posted. Platinum plugs may well be a better value because they last a lot longer in my experience with them compared to the older technology. He may end up spending less for the "expensive" plugs. It's life cycle costs that need to be compared to brand new out of the box costs.
scoflaw
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496 mag B1
Plugs should never look like that, low speed won't do that especially efi. Find your problem.
Nater Potater
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While your plugs are dirtier than expected from the prior throttle body issue, keep in mind that, with the elimination of lead in our fuel, plugs don't color the way they used to. As you can see in the cut-away view here, the nose of the insulator should be just about clear of any deposits, with a gray ring down inside where the insulator comes in contact with the steel shell.
However, as mentioned by others, you may need to go up one heat range to keep your plugs from fouling. Just be careful that that isn't accompanied by WOT detonation, as you run the chance of severe internal engine damage if it does.
For a sanity check (once weather and time permits), run your boat for a few minutes with your current plugs at WOT, chop the throttles and kill the engines, and pull a couple of plugs. As long as your fuel system is working as it should, I'd lay odds your plugs suddenly look a bunch better.
However, as mentioned by others, you may need to go up one heat range to keep your plugs from fouling. Just be careful that that isn't accompanied by WOT detonation, as you run the chance of severe internal engine damage if it does.
For a sanity check (once weather and time permits), run your boat for a few minutes with your current plugs at WOT, chop the throttles and kill the engines, and pull a couple of plugs. As long as your fuel system is working as it should, I'd lay odds your plugs suddenly look a bunch better.
Last edited:
techmitch
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Couldn't agree more!
boater2065
Active Member
The problem i have, as some have mentioned about the photos i posted of the plugs, is each plug looks fouled differently. Not sure how to begin diagnosing it because of that. I'm tempted to replace the plugs again with new ones now that the throttle body is repaired. Would they look the same, better, worse etc
scoflaw
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496 mag B1
Sure replace them , I'd start with that first after a repair with a 3 dollar plug of the recommended variety
techmitch
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Unless I missed it we still haven't heard the results of the W.O.T test nor the compression or or leak down test (specifically in that order) that Scoflaw and I posted earlier in this thread.
With the results of the test we can help you, without them, well. I'm out.
To perform a complete and comprehensive diagnosis, you should NEVER skip steps.
boater2065
Active Member
I hear ya. I'm in the process of figuring out how to do the compression and leak down test, as well as acquire the tools needed to do so. I appreciate everyone assistance with helping me out, and i'll respond back whenever i get these tests done
techmitch
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Ok sounds good but I highly recommend to do a good warmed up wot run before those test for best results. After the wot run and compression you will know if you have a good base engine or, if low compression a leak down test will tell us where its going.
If you still have fuel or ignition problems, they could seriously skew the numbers, sometimes to the extreme.
boater2065
Active Member
Sounds good. How long should i run wide open for? A minute or two, take note of the RPM at WOT, then back to the slip to do compression tests?
techmitch
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Edited above, but yea, a fair bit longer than that will give you a better idea of the cooling system performance but that may be of little concern right now.
Nater Potater
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If you're going to take a plug reading at the same time, it needs to be done out on the water without any interim run time after having run wide open. Plugs color amazingly quickly, and any partial throttle running will mask what the WOT color was.
89P270
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I am chiming in a bit late here so take this for what it is and maybe supporting others as I didnt see in the 4 pages whether you completely pinned down the problem. I had a Rinker with With 6.2L and Bravo IIIs. I had the marina, after I first purchased the boat, pull both outdrives for service. Didnt use the boat for few months as it was winter (I think the service was in January when the marina runs a 1/2 off labor). When I went to use the boat first time in spring, was out motoring (WOT at times) and hard alarm sounded. Limped back to dock and noticed significant sheen like this out the stern. Did inspection and found outdrive oil reservoir on one side was very low (ie the eventual hard Alarm). Upon testing, only saw the sheen when engine was running. So, the culprit, the marina on that Bravo III reinstall pinched or improperly sealed the through transom oil reservoir tube connector to the back of the outdrive. The outdrive was removed, connector refitted properly, no more leak. In my case was obvious due to the volume loss of gear lube from the reservior. However, I could see a minor mis-seal manifesting in a much smaller way like this. Now, after every service no matter what is done, I run the boat to make sure all is good. I have other horror stories from Mechanics not paying attention and covering their disconnect/reconnect tracks too. This is just one of may. Also, one of the weak links of the Bravo III - The 1 inch to 5/8 inch restriction for cooling water through the transom is yet another pitfall of them. Still, the performance is very good and the good outweighs the bad for these outdrives.
