lead additive

powderhombre · Sep 4, 2009

I hope this isn't considered an engine question, but where can you buy a lead fuel additive for older power plants? (I/O) I've tried checker, Wally world, carquest. no one seems to have it.

HappierWet · Sep 4, 2009

Re: lead additive

I don't have a good answer for you yet....However A QUESTION, What's an older power plant? Are you sure you need the lead additive? My understanding is that with a 4 cycle motor ( your i/o ) as long as the valve seats are hardened you don't need the lead.

gss036 · Sep 4, 2009

Re: lead additive

I haven't seen this product on the shelf for several years. I have about 1/2 bottle sitting on my shop shelf. I have no idea where you are located, but don't think one could ship it after it has been opened. I used it for a 1976 Dodge 360 V-8.

ziggy · Sep 4, 2009

Re: lead additive

i've been successful getting it at orileys.

the lead substitute is kind of a debatable subject. don't know about the op. but i don't have hardened seats. so i should use lead additive. which i do. but from most of the reading here. most will probably say just run it w/o. something else will go wrong long before there's ramifications from the lack of lead in the fuel. use the search function on iboats for lead additive. you'll likely find more than a few comments on it's use or non use.. i'd search in the i/o forum as it is engine related...

Lion hunter · Sep 4, 2009

Re: lead additive

I still see it on the shelf at auto parts stores. It may depend on where you live. I had a 72 ford that I ran it in for a long time. I finally quit thinking that I'd just let it burn the valve guides and get the heads rebuilt. I never had any trouble without it. May have been something to worry about when an engine was new but by the time its been run for 30 years theres probably enough clearance in the guides that the additional lubrication is not needed.

powderhombre · Sep 5, 2009

Re: lead additive

thanks guys, the power plant is an 82 -v6 Chevy OMC. I'm pretty sure it was built with leaded fuel in mind, I think it is mentioned in my OMC owners manual, which I can not find at the moment. the engine has very few hours on it, I believe, and it does not smoke at start up, a classic sign of worn valve guides, and I would like to keep it that way.

Lion hunter · Sep 5, 2009

Re: lead additive

The phase out of leaded fuel started in 1975 (I think) and was complete by 1986. I would think by 1982 they would have not built a motor requiring it. Had a 1983 Chevy P/U w/ the 305 and it required unleaded.

I really don't know how well the substitute works. The original purpose behind the lead was to stop preignition in high compression engines. An added benefit was that the lead also acted as a lubricant and cushion on seats and guides. I don't know if the substute actually lubricates well or just stops engine knock

jkust · Sep 5, 2009

Re: lead additive

One of our boats is an 84 with an ob requiring leaded gas. We just caught the tail end of leaded gas when we bought it in 84. We have always used lead additive since the day unleaded replaced leaded gas. Just part of the routine when at the gas pump with the tanks. It has been several years since buying the additive since the bottle was big but the local auto parts store had it then.

Lion hunter · Sep 5, 2009

Re: lead additive

jkust said:
One of our boats is an 84 with an ob requiring leaded gas. .

Is this a 4 stroke OB? I can't imagine a 2 stroke needing any additional lubrication or have high enough compression to require any additive other than oil. I know it was standard thinking that leaded fuel was superior to unleaded for a long time and many manufacturers probably added that as a recommended fuel. I have never used any additive on any of my old 2 strokes. But if it's working for you I guess I' stick with it.

windsors03cobra · Sep 5, 2009

Re: lead additive

Waste of money and snake oil, GM engines were designed to use lead free in the mid 70's.

No lead additive, substitute. Again, WASTE.

To each their own.

Lion hunter · Sep 5, 2009

Re: lead additive

windsors03cobra said:
GM engines were designed to use lead free in the mid 70's.

That's what I thought as well, as soon as the phase out began in 1975 the Government required new engines to be able to run on unleaded fuel.

windsors03cobra · Sep 5, 2009

Re: lead additive

In 1973 AC (theres a dead oldie) the huge GM parts supplier now know as Delphi built a plant up the road a piece here in Oak Creek that produced millions of catalytic converters between 1973 and 2008. In 1990 Oak Creek built the 100 million AC cat converter.
Pretty sure any car that was cat converter equipped would be a no lead vehicle, I know a 1977 Buick Electra I had with a 350 engine was a no lead car. Had the little flapper door and nozzle restrictor to prevent the leaded nozzle from going into the fuel filler.
Heck I remember warnings to people about "widening out the no lead fuel fillers to accept leaded fuel".
I guess the leaded fuel was cheaper and or folks really wanted that lead ?

jkust · Sep 5, 2009

Re: lead additive

Lion hunter said:
Is this a 4 stroke OB? I can't imagine a 2 stroke needing any additional lubrication or have high enough compression to require any additive other than oil. I know it was standard thinking that leaded fuel was superior to unleaded for a long time and many manufacturers probably added that as a recommended fuel. I have never used any additive on any of my old 2 strokes. But if it's working for you I guess I' stick with it.

No it is a 2 stroke. The manual says it requires leaded gas so thats what we have been doing plus the lead does provide some lubrication. Recall too that the motor was just a year or so old when they went unleaded and still making payments so we were just protecting our investment. My take today is that the engine in 25 years old has had one set of plugs and zero other maintenance or preventative maintenance other than winterizing and it didn't even need the plugs. This engine must have been made on a Wednesday or we are just lucky since it is a Force. I don't hear or see anyone else using lead but why mess with a good thing?

Lion hunter · Sep 5, 2009

Re: lead additive

Like I said "if it works for you keep doing it" I can't imagine it doing any harm. I've had some motors that if I thought a troll on my dash would help it I would have kept doing it no matter what anyone said LOL. But you are truly the 1st I have ever heard of using it on a 2 stroke. All my old manuals also state leaded gas. I have never worried about it. And with the advances in oils I worry even less. Any 4 stroke older than 75 with orignal heads I would use it.

lead additive

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