Mercury runs smooth after warm up

[Chris Flanigan]

I bought a used a '97 Nitro with a 115 2stroke (oil injected) Mercury 6 months ago.

Lately it has been running bad when it is first started. It starts in fast idle easily but

quits when put in neutral (idles rough and smokes more than normal).

Once you run it for about 2+ minutes, it seems to run much better and idle normal

with less smoke.



Tried so far:

Use only Mercury premium plus oil

Emptied whole gas tank

Replaced fuel bulb

Replaced fuel filter

Checked spark plugs (black but not wet)

* It ran perfect the day I did all this (even when started cold). The next time out it ran rough when starting again.



I was wondering if we are skipping something when we take it out of the water. Do you somehow drain the gas (or run it out) from the cylinder or disconnect something? It seems either fuel or oil injection related.



Thanks

 

[Rich Stern]

Might need to run some fuel system treatment (Mercury, Seafoam) through it. The carbs might have some varnish build up.



Could also be a bit of water building up in the gas when you don't use it. Does it sit outside, or is it garaged? An outside boat does this a bit more with the warming/cooling cycles, which can create condensation inside the fuel system.

 

[JD Johnson]

Have you run some of the de-carbonizing products though it yet? Others will know more about this than I and speak up hopefully

 

[Steve Rizza]

I would do like Rich said. Run Sea Foam in it for awhile and see if it helps. It's good stuff.



Also what JD said. I decarbon mine every year, and it's amazing how much junk blows out the exhaust when you do it. I always used the Merc brand, but my mechanic at the marine swears the Yammie Ring Free is alot better. I'll be trying it this year.



Also change out your spark plugs. You can always clean up the old ones and keep them in the boat for spares.



Steve

 

[JD Johnson]

I always used the Merc brand, but my mechanic at the marine swears the Yammie Ring Free is alot better

Steve, the Yamaha Ring Free is excellent stuff but it is the same as Chevron Techtrol which is cheaper. Chevron makes the ring free with Yammie's name on it, I have used both in my motorcycle and now use Techtrol only.

 

[Jim in VA]

Chevron Techtrol?

Do you mean Chevron Techron? The stuff that cleans carbs and fuel injectors? If so, then I can tell you from first hand experience that Techron works pretty well. I've used it quite a bit in my motorcycle as well and it definitely helps. And this coming from someone who believes most of that additive stuff is hooey! Very few additives actually do what they say - in my experience, Techron is one of those few.



JC

 

[Steve Rizza]

I'll look into that JD.

I've only ever used the Merc De-Carb, but I hear every trip to the shop how good Ring Free is.:wacko:

I figure I'd better try it just so I don't have to hear him nagging my anymore.



Steve

 

[JD Johnson]

Do you mean Chevron Techron?

Yes I do, it was the drugs I'm not on I swear they cause huge brain farts.