spark plugs

[Mr. BrownTrout]

I just took my new boat up to the lake today, it ran ok. The boat is a 15' truline fiberglass vee hull with a 70hp evinrude outboard. The motor had been winterized, I put a new fuel tank in the boat, so it had fresh gas. It did not quite push the boat as fast as I thought it would. We went up the lake a few miles, then started running back down to the ramp when the engine made a funny noise and cut out. So we limped back to the ramp, just before we got back to the ramp them engine perked up again, so I ran out a little ways and then it cut out again. I got home and took the cover off and found out it had champion spark plugs in it, now I am not a fan of champion plugs, I have always ran NGK plugs. So on payday am going to go buy some NGK plugs and try it out again next weekend. Does anyone else have anything to add that I might have be not seeing here. When limping back down to the ramp it would only go 6mph.

[fishkisser]

Fuel water separator or fuel filter ...
Was it a portable or a built in fuel tank you put in the boat ?
How long has it been since someone cleaned the carb ?
Is the spark blue/white or red/yellow ?
Could your timing belt have stripped a tooth ?
How long since new ignition wires ?
I sure got a lot of questions don't I ...:D

[GSD]

I'll be easy on ya, I'm only going to ask 1 question.

2 stroke or 4 stroke?

:wink:

[Mr. BrownTrout]

2 stroke motor. The tank was brand new, its a below deck tank that I mounted inside the center console. There is no inline filter on the hose.
Mix the gas and oil at 50/1

[Bloom]

You might want to check the fuel tank vent. If it's a portable tank, the vent should be on the cap, otherwise, check the tank vent line to make sure it's not plugged or kinked.Without a filter, you may have a partially plugged carb.You should pull the plugs and read them as well, but try one thing at a time so you'll know what the culprit is.Double check those plugs for the correct heat range. Was it smoking heavily? If so, you may have a stuck choke(happened to me with a 35 Johnson).
Good luck and let us know what you find.

[Mr. BrownTrout]

It did not smoke at all, but it did smell like it might have been running a little rich. I thought the guy that sold it to me said the carbs had been rebuilt.
I think the first thing I am going to do is put some NGK plugs in it and maybe some type of carb cleaner through it.

[fishkisser]

Hooking up a water separating fuel filter will save you a lot of repairs down the road ...
Pulling the float bowls on the carbs will tell you a lot about what was done to it if anything ...

[12pulls]

I had a 99 Merc crap out once at TBay, running fine then not. Turns out one of the plug wires was not firmly connected. Check the simple things first. Also, try a can of engine tune run through it, smokes like a dickens but makes a huge difference in running. This should be done once a year after a tuneup, especially with the ethanol fuel we are getting now at the pump. Todays fuel just does not burn complete in two strokes, especially motors used for trolling.