Pontoon Boat & Deck Boat Forum

Anyone have first hand experience of an additive like Star Tron making a noticeable improvement in their motor performance? (and in a relatively quick/immediate time frame--say a few hours of run time or 1 tank?) I don't like to put trust in online comments from the manufacturer's website, so hoping one of you has had success. I was using Seafoam in E10 fuel but have now switched to non-ethonal gas, which also happens to be 92 octane (only choice for non-ethanol on my end of the lake).

The problem is I've been experiencing a slow drop in max RPMs over the last year or so and want to try little things first. So far I've replaced the water separator and the filter at the back of the motor. Next will be getting into the VST, but I don't want to do anything like that before the 4th where I could possibly F something up and jeopardize a good week of boating.

First off, how much power loss are you experiencing? Second 92 octane in an engine designed for 87 won't perform as well as it does with 87. Also on open loop efi systems E10 may actually perform better that regular gas as the engine will run a touch leaner. Between those two thing you could be seeing a 5-10hp difference on a 150hp engine. Injectors really don't get dirty, and I don't see that being the issue unless all you do is idle and use REALLY crappy gas consistently.

I'm down about 500-600 RPM at WOT over the last 15 months or so, and it's happened gradually. I've gone back and forth with my two props and the loss is about the same with both. The load in the boat is usually around the same, so that's not the issue either. I'm only on the second tank of non-ethanol super.

I have done a fair amount of trolling, which is at idle speed/RPM--not sure how many hours like that but I'd guess around 20 and the motor has about 220 hours. It was topping out around 5,400 RPM with the stock aluminum prop when I bought it, and now it's under 5K with both props.

With modern gas there really isn't a need for injector cleaners. Use it if it'll make you feel better, but there's usually no mechanical need for it.

About the engine turning fewer rpm's. I've had this problem too. Turns out my linkage wasn't adjusted right. Ran fine when the temp was cooler (been at 108 for the past 2 days), but I'm not getting the rpm's I did when the temp was in the high 80's. The answer (in my case) was the coefficient of expansion. I've seen it on rigging aircraft. One must take into consideration the ambient temp when rigging the controls.

To put this into plain-speak; aluminum expands (& contracts) more than steel under temperature fluctations. What happened in my case was that my engine wouldn't go into reverse when it got hot. It worked just fine in 85 degree weather. Pntoons are made of aluminum. The control cables are made of steel. When it gets hot, the aluminum expands more than steel thereby effectively shortening the steel control cables. Ergo; the control cables can't reach their full travel on a hot day so the engine's fuel control unit (in my case carbs) don't open up all the way (throttle positon) or go into reverse (lower end tranny shifting). My boat's 32' long so it's more susceptible to heat expansion than most pontoon boats.

I simply lengthened the cables travel (at the engine in my case) by extending each by 1/4." On my boat I did this by screwing the thingamawhopper (the exact name eludes me now) which holds the cables at the place where they are held to the engine. The same thing could be achieved by backing out the rod ends on the cables a bit. I just did it the easiest way since I had to do both. Either way will work. But, as a general rule (on aircraft it is a rule) that a rod end will have a small hole in it. On aircraft at least, if a bit of .020 wire (more often .032) will go into this hole, the rod end is over-extended, you'll have to back the rod end untill nothing can go into the hole. Extend the cable from the other end in this case. Or change the postion of the thingamawhopper which secures the cables before the rod end. There's one on each end.

Hope this helps, just a thought.

Please don't be offended. Do you leave your boat in the water? If so, have you cleaned the toons lately? Even just a small amount of scum on the bottom of the toons could cause an rpm drop.

I had checked the linkage/throttle movement before, and had cleaned the logs as best I could from out side the water (too cold before, boat is is slipped). This weekend I revisited both areas and got maybe another 1/16th to 1/8" more travel out of the throttle cable at the motor (essentially maxed out now) and had the kids scrub the toons. Might have gained 50-100 RPM between the two but hard to tell since conditions weren't exactly the same. I'm going to try and find someone at the marina who knows outboards to double check the linkages for me since this is my first outboard, but I just don't see where any more travel could be gained.

I've read plenty of posts elsewhere about people getting their outboard injectors cleaned and experiencing much improved performance, including on my same motor, and the Yamaha authorized dealer here thought that was my problem (without him looking at the boat, just based off my description of performance). Of course he wants $100 to hook it up to the computer just to get started.

After boating this weekend I ran into a guy at a gas station with Mobile Marine Repair decals on his truck. I asked for his card just to have in case of emergency, then said I hadn't had any major problems but I have been noticing a drop in RPMs over the past year. His first response (after asking about type of boat and motor and how many RPMs lower) was that a pontoon may be leaking. When I said the boat wasn't listing at all he said, "Well, I tell all of my customers to add fuel injector cleaner regularly--and don't follow the instructions, dump the whole bottle in." That was without me saying anything about potentially dirty injectors, so I found that interesting. No idea if this guy is any good or not, but his card says 15+ years certified mechanic and lists a bunch of brands he services (Yamaha was not one of them, though).

I'm thinking the injector cleaners are either a bust or else dirty injectors aren't the problem with my boat/motor. Tried a bottle of Lucas and a bottle of Star Tron. Thought I had a slight improvement (50-100 RPM) but there are just too many variables to know if the additive was the cause. So I think the $5 for that stuff would be better spent giving to my kids to scrub the toons. However, I also used Star Tron in my weed eater fuel and that is now running as well as it ever has.

I think these additives are mostly snake oil.
One thing you have to think about is whether your boat got heavier. Sometimes it is water in the toons but there is also the problem of bringing things down to the boat and not taking them off. You can accumulate a lot of stuff over the years.
My boat always gets lighter when I replace the carpet, just because I have to take everything off and then it gives me a chance to say "why am I still lugging this around" before I put it back on. Last time I figured out I had 4 anchors and I only use one. I lightened my tool box by about 20 pounds, just by getting all the SAE tools off the boat. I had parts for motors I don't have and stuff like that.

I agree with the snake oil comment for the most part, but I'm a huge fan of Marvel Mystery Oil. I owned a small fleet of diesel trucks under contract with FedEx and one developed a problem with idling, it would run at high rpm's but would die at stoplights. My mechanic said it needed a new injection pump, almost a thousand dollars parts and labor.

Then I remembered an old-school mechanic at an International Harvester dealership I had worked at telling me about MMO. I figured it was worth a try so I poured the recommended amount into the fuel tank and within a few hours the truck idled perfectly. It became part of my maintenance routine, adding a bottle to every truck each month.

When a friend called me about his classic VW that had come out of storage with a similar problem, I drove over and dosed it with MMO and it started running properly within twenty minutes. He keeps a bottle on hand now.

As much as I would like to say all additives are a waste of money, I can't argue with the fact that Marvel has saved me a lot of cash. I run it in every engine I own.

Diesel injetors have to be cleaned on both sides, the oil side as oil presure fires the injector and the fuel side, I was getting a miss at idle now a then, I ran hot shots secret in the oil for a month to clean the oil side and picked up a mile per gallon, then switched to AMS Oil to keep it clean.

I use Power Service Diesel, Gray bottle along with 2 ounces per 10 gallons of 2 stoke oil for the for the fuel side

I always use injector cleaners and try to keep it in the suv. Tried lots of diff ones. seafoam (cheaper by the gal per oz.), gumout (Pretty much the one I have been using for years) Probably the cheapest for it's cleaning ability per oz.
You said you tried Lucas was that in the small bottle or the one that come in the ketchup looking bottle? Tried the small bottle with little or no change but the larger one gave much better results. Put some in my sister car when she came down last week and she wanted to know where to buy it, when I saw her yesterday. Sort of surprised me cause she hardly know when the motor is running right or not. The first time I had used a couple of weeks ago it increased my gpm about 4/10 of a mpg in an 80 mile trip on the interstate. Whatever cleaner I am running I always increase the amount recommended. In the stabil case it was about half the large bottle in a full tank. The restore products have worked well also, but seem to be a little harder to find here lately. The additives seem to be keeping pace with the rise in gasoline, so any savings mpg wise may be cancelled out by the cost of the product, but nice to have a smoother running engine anyway.
doc

When I used the Lucas product it was the tall skinny bottle, meant for 25 gallons, which is about how much gas I had in the boat. With the Star Tron I put in the whole bottle, which I think was 3-4 times the normal dosage.

Weight creep on the boat can definitely be a factor--carrying about 50 pounds more this summer just from my 2 kids. Don't think I've added any extra gear though, but now the kids are eating and drinking more than adults so the cooler is heavier now, too.

Badger wrote:I agree with the snake oil comment for the most part, but I'm a huge fan of Marvel Mystery Oil. I owned a small fleet of diesel trucks under contract with FedEx and one developed a problem with idling, it would run at high rpm's but would die at stoplights. My mechanic said it needed a new injection pump, almost a thousand dollars parts and labor.

Then I remembered an old-school mechanic at an International Harvester dealership I had worked at telling me about MMO. I figured it was worth a try so I poured the recommended amount into the fuel tank and within a few hours the truck idled perfectly. It became part of my maintenance routine, adding a bottle to every truck each month.

When a friend called me about his classic VW that had come out of storage with a similar problem, I drove over and dosed it with MMO and it started running properly within twenty minutes. He keeps a bottle on hand now.

As much as I would like to say all additives are a waste of money, I can't argue with the fact that Marvel has saved me a lot of cash. I run it in every engine I own.

I have a customer who runs a little MMO in his air brakes and has for years. In the winter time to keep from having freezing issues and claims it keeps problems usually accustom with moisture from becoming a problem

All four stroke engines need to be decarbonized atleast once a year. I suggest using gm fuel system treatment plus. It is sold at gm dealerships and is about 24.00 a bottle. Just follow the directions on bottle and i guarentee you it will clean all carbon off your valves and pistons. I call it ( miracle fix in a bottle) i have been using it in everything i own since 1998. You will not be disappointed. If you do alot of trolling you will build up carbon fast with our gas being junk that it is you rob your engine of power and rpm's. Try it yiu will be surprisef.
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