Outboard Carb Cleaner

[Hysteria]

I'm looking for an additive for a new to me 2 stroke Mercury 150 (carbureted) that didn't get much use over the last few years and seems to run a little lean at idle. Do I just want a high PEA additive for this situation or are there some other considerations at play? I drained most of the fuel out and switched it to rec90 with marine sta-bil, which is what I will use going forward.

The boat seems to rev out fine and run well other than at idle, so I don't want to pull the carbs off it just yet. I'm hoping to run some cleaner through it and then adjust the idle mixture afterwards to see how it reacts.

Thanks guys

 

[jhs914]

https://www.westmarine.com/buy/yamaha--ring-free-fuel-additive--2280683

 

[Hysteria]

https://www.westmarine.com/buy/yamaha--ring-free-fuel-additive--2280683

I appreciate the link, but that seems to be a carbon cleaning product, which isn't really what I'm after. I'm looking for a fuel system cleaner that might clear up the idle circuits a bit.

 

[demarpaint]

I appreciate the link, but that seems to be a carbon cleaning product, which isn't really what I'm after. I'm looking for a fuel system cleaner that might clear up the idle circuits a bit.

It should work fine, although it's not cheap.

 

[Brian123]

Mechanic In A Bottle, you can get it from Amazon or Home Depot, lots of testimonials at both places.

 

[danez_yoda]

No harm in trying. Run a hot mix of Techron through it. Also good reports from Seafoam. If its a plugged jet, it would lean out at high RPM then low. likely something else. Not sure if there is a low speed jet in these engines or just one jet.

 

[Hysteria]

No harm in trying. Run a hot mix of Techron through it. Also good reports from Seafoam. If its a plugged jet, it would lean out at high RPM then low. likely something else. Not sure if there is a low speed jet in these engines or just one jet.

I'm just trying to be careful that I don't add anything that is going to affect the lubricity of the fuel/oil mixture and cause more harm than good. Not sure if it's possible to have a good solvent that can remove varnish/deposits without affecting that though. I'm not sure how the idle circuits are configured on these carbs, but I thought it might be worthwhile to run a cleaner through it before I try to tune & synch them.

 

[danez_yoda]

gasoline is a pretty good solvent in itself. Especially of it has 10% ethanol in it. I don't think you can thin out gasoline. If you engine is like my 1999 Merc 90 the it has a oil mixer to keep the fuel ratio set regardless of the gasoline type. you could run pure water in it and it would still get the current ratio. not for long though...

 

[Hysteria]

gasoline is a pretty good solvent in itself. Especially of it has 10% ethanol in it. I don't think you can thin out gasoline. If you engine is like my 1999 Merc 90 the it has a oil mixer to keep the fuel ratio set regardless of the gasoline type. you could run pure water in it and it would still get the current ratio. not for long though...

I'm hoping it will clear up a little more as I run it, I wouldn't mind having something in the tank that assists with that though (rec90 is ethanol-free). The oil injection on this boat still works, so it will get 50-100:1 oil added no matter what.

 

[samven]

So I am guessing that you have already pulled the plugs and checked the gaps as well as for carbon build up. I am also guessing that this is a rather old engine as its a 150 and still carbed. If this is right then try syncing the carbs and run some seafoam but old Mercs never ran real well at idle and carboned up real fast when you did much trolling. The auto oiler mixes at 50:1 at the lower speed and sometimes I think it was richer than what they say by the amount of smoke they would kick out when you hit the throttle. I hate to generalize but old mercs were meant to be run fast and they did that very well but every guy I know that ran them always had a small 9.9 Johnson hanging on the transom for trolling.

Edit: When a 2 stroke runs lean it want to rev higher, if its coughing it might be rich.

 

[jhs914]

I appreciate the link, but that seems to be a carbon cleaning product, which isn't really what I'm after. I'm looking for a fuel system cleaner that might clear up the idle circuits a bit.

From the manufacturer:

Highly concentrated YamaLube Ring Free PLUS is a proven engine deposit cleaning package. When used as directed, this top-quality deposit-control sytem removes deposits from fuel injectors, carburetors, intake valves, intake ports, and combustion chambers.

 

[Hysteria]

So I am guessing that you have already pulled the plugs and checked the gaps as well as for carbon build up. I am also guessing that this is a rather old engine as its a 150 and still carbed. If this is right then try syncing the carbs and run some seafoam but old Mercs never ran real well at idle and carboned up real fast when you did much trolling. The auto oiler mixes at 50:1 at the lower speed and sometimes I think it was richer than what they say by the amount of smoke they would kick out when you hit the throttle. I hate to generalize but old mercs were meant to be run fast and they did that very well but every guy I know that ran them always had a small 9.9 Johnson hanging on the transom for trolling.

Edit: When a 2 stroke runs lean it want to rev higher, if its coughing it might be rich.

Appreciate the input. You are right, it is an older (2002) Mercury XR6. The oil pump is supposed to inject 100:1 at idle and 50:1 at WOT, but after seeing how the system is set up I've got some questions about that. I'm pretty confident that it's running lean because when I hear it start stumbling I can hit the fuel enrichment for a second and bring it back. I'm not planning on trolling with it, so if I can get it sorted out to where it will idle without dying I'll be happy.

 

[RTexasF]

Yamaha Ring Free is a superior product. Back in the mid 80's I sold Yamaha outboards and the Ring Free was clearly labeled Chevron Techron. That's possibly no longer the case but it gave me new respect for Techron. Running a shock dose of 2oz per gallon might help the idle.