I have a 2020 Diamondback with the 6.2 LSA supercharged engine. Boat has a little under 150 hours on it. I have been burning through spark plugs. When I 1st got the boat they told me to run high test pump gas in it and I did. A little over 30 hours, it developed a miss and wasn't running as strong. Checked the plugs, and that was the issue, there was at least one fouled plug. Replaced and had it happen again at a little over 60 hours. DB tells me it's bad gas, and to switch to the highest octane non-ethanol gas I can find. All I can find is Rec90, occasionaly there is a store or two that have Rec92. Anyways, that lasts me up to about the 143 mark and bam, I develop the miss and power loss again. Two dead cylinders and sure enough the plugs look bad. Pulled the plugs and put new ones in. Not all look bad, but several did and the port side of the motor looked worse than the starboard. Mind you, this was a brand new "off the shelf" boat in 2020. I have heard that FWC has a similar boat to mine and they are having issues with the spark plugs as well. Any ideas? Is it too low of octane of fuel? Do the octane boost additives work? I love my boat, and it'll follow a sweaty mule down a dirt road when it's right, but the plugs for it are expensive and I'd really like to find a remedy if possible. Thanks for any help you can offer.
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Levitator/LSA 6.2 Supercharged Issue
- Thread starter hlb2
- Start date
hogdoggin
Well-known member
Just a thought. Is there any engine codes showing up? I would suspect the 02 sensor has taken a crap and it’s running rich. Fuel octane shouldn’t be causing fouled plugs. Low Octane causes detonation. Over in richment would foul plugs or oil. If it were me I’d look into the 02 sensor
Slidin Gator
Well-known member
X2 on this, the bad fuel response is just lazy BS "I don't know what I'm doing/talking about" response. However, given that the problem has existed since new it is also possible that you have a leak in your exhaust near the O2 sensor, resulting in a rich mixture. Post some pics of the exhaust. The O2 sensor needs to be at least 18" upstream of any contact with ambient air.
Is it the same cylinders every time or random? If random, do the rest of the plugs look rich? If so, see above.
If the same cylinders then I would also move the injectors around to see if the problem follows, or just send them out for flow testing and cleaning.
PCM specifies 91 Octane. I'm sure Rec90 will work, particularly if you use octane booster. But it will probably run best on 93 premium even with 10% ethanol. Just don't store it more than a few weeks with ethanol fuel without stabilizer added and run through the engine. If you have avoided ethanol fuel, be prepared to replace the fuel filter after a tank or so.
Honestly, I have not paid that much attention to which cylinders it is, which is unfortunate. No codes have been thrown whatsoever. I'm pretty sure DB and PCM engines are set up correctly as they churn out a large number of these yearly. I do not currently run octane boost as I've always been told that's just a "money grab" (does it really work????). I figured the same thing for the fuel stabilizers too, they were just money grabs and didn't really do anything. I do have a member on my hunt club that swears by the Startron stuff. He worked at a rural fire department for many years and they kept it in all their chainsaws and pole saws and he said they never dealt with anything not running and he said a lof of that equipment would sit most of the year unused. The boat has been back up to DB once to check for codes etc, but nothing was found and that's when they chocked it up to the poor quality of fuel being put out these days. I highly doubt their head LS engine guy would not know what he was doing at a company like DB.
Slidin Gator
Well-known member
All good fuel stabilizers, I use sta-bil.
Is the engine/boat still under warranty?
Search this site and you will find a lot of discussion of issues with the PCM SLA. Note that they don't produce boosted engines these days.
Is the engine/boat still under warranty?
Search this site and you will find a lot of discussion of issues with the PCM SLA. Note that they don't produce boosted engines these days.
Engine is no longer under warranty.
I'd have to find the pics of the plugs, I think I have some.
Did not smell the plugs, but no oil dripping off of them, I just remember a lot of carbon. Also a couple were reddish in color too.
They did hook it up to the computer when I had it in their shop.
I'd have to find the pics of the plugs, I think I have some.
Did not smell the plugs, but no oil dripping off of them, I just remember a lot of carbon. Also a couple were reddish in color too.
They did hook it up to the computer when I had it in their shop.
Aeon
Well-known member
Limited info but here goes
One add a catch can to the pcv system. You could be oil fouling the plugs. Even if you are not it's still a good idea. Get one off Amazon and mount it up.
Two, take a heat gun and shoot your headers. They should all be the same temp more or less. If they are not that's a good sign somethings off. Since you said not all the plugs were the same I bet you find a temp variance. Do this with new plugs! Heat guns are cheap now and a great tool.
Three, go find a off road race shop, or a shop that tunes ls motors near you they should be able to hook up to your ecm and put a sniffer in the tail pipe and fix your tune. Or atleast tell you something is off like a bad injector
One add a catch can to the pcv system. You could be oil fouling the plugs. Even if you are not it's still a good idea. Get one off Amazon and mount it up.
Two, take a heat gun and shoot your headers. They should all be the same temp more or less. If they are not that's a good sign somethings off. Since you said not all the plugs were the same I bet you find a temp variance. Do this with new plugs! Heat guns are cheap now and a great tool.
Three, go find a off road race shop, or a shop that tunes ls motors near you they should be able to hook up to your ecm and put a sniffer in the tail pipe and fix your tune. Or atleast tell you something is off like a bad injector
I didn't think you could take PCM motors to just any shop? I thought it had to be one that was PCM certified. I was pretty sure I read that somewhere or was told that. If I'm wrong, that's great news, because Cocoa is about 3.5 hours from me.
Aeon
Well-known member
no clue if levitator locks their ecm so you can only get it worked on by them( good chance its locked down) .....if the ecm is bad and you cant get them to fix it then ditch it and run a holley hp. not exactly free but they work rad. zero clue if the wires will hook up or you will need a new harness.
