Marine 2-stroke oil

[NotGivingUpYet]

Looking for some advice on this stuff... EXOL TC-W3

MARINE TWO STROKE TC-W3

We're currently using it in our early 70s Merc 50hp , but having a few problems with high end power and plugs oiling up.

We've recently cleaned carbs out, so might just need a little more tinkering with setting them up, but I'm just trying to rule out potential issues.

Anyone currently using it or has done in the past can give any feedback or advice on what you'd suggest using?

Other potential issues include possibly air intake into fuel line, which is next on the list to be ruled out, but if anyone can offer any other checks, it would be appreciated.

SYMPTOMS:

Starts and runs ok on dry land with muffs, but when we had it out at the weekend, it wasn't giving full power and after a while cut out. It starts and runs again after this, but again chokes up when throttled.

We'll be checking compression this week and running it on separate fuel tank to rule out these, but I understand the carbs are best set up when it's in the water. I'm guessing this is an exhaust thing. The extra volume of water acting like a baffle.
Next in line could be a link n sync. Any pointers on approximate cost of this?

Cheers

[Russ hud]

Alright Neil, was the outboard running ok before you started using the oil and cleaned up the carbs? Hope im not trying to tell you how to suck eggs but is the tank vent open? pick up in tank clean? fresh fuel? priming bulb ok? fuel filter ok? If the carbs been off I believe that you should link and sync. I think if you take it for anyone to have a look at, a compression test would prob be first think on the list.

Good luck anyway and let us know how you get on.

Russell

[NotGivingUpYet]

It hadn't been run for a couple of years before we bought it m8, so we were expecting the odd issue.

So far we've:

Stripped & rebuilt both carbs.
Replaced the solenoid.
Checked / cleaned fuel filter.
Replaced gearbox oil.
Replaced plugs.
Replaced impellor (that was fun as the bottom end hadn't been off for some time and was seized on)
Replaced fuel line including primer bulb.

Like I mentioned, we're planning on checking compression this week, but it sounds like it's running ok at idle.
We noticed a small leak on the fuel line connector to the tank, so I suspect this may be drawing air into the fuel line. Again this is something we hope to rectify this week before giving it another run.

I just wanted to check if anyone had issues with this oil as I've read some write-ups where people swear by a certain brand for certain engines.

I'll keep you posted.

[Kev1n]

The air in fuel leak sounds a promising lead to follow.

Was it running OK when last used?

Were the diaphragms in the carb OK, they could have perished over time.
Some oiling of the plugs is expected but if it is too much then the plugs won’t work as well as they should. Can you check that the engine has the right plugs in, if they’re the wrong ones, they may not be getting hot enough?

[hollygolly]

i had the same problem with an evinrude 70hp, and did all those things you did, it turned out to be a faulty coil on one of the pots. i also found it to have a small, very small, leak at one of the fuel line joints. It is also VERY important to have the carb linkages spot on in sync, if one is slightly out you will get the same effect when you throttle under load. Unless your compression is well out i doubt it will be that.