2 stroke oil blockage in head or exhaust?

[ba_50]

We have checked and rechecked everything on this 9.9 J10 Rena and it still won't accelerate but idles perfectly.

It had a bad fuel pump and oil sludge running out of the top and bottom exhausts. It sat for maybe a year or 2 like that. I took the exhaust cover off and cleaned out the goo in the holes. They were half way plugged. Where else would this oil accumulate and prevent it from powering up? Is there an easier way to clean it out then take the power head, lower unit and midsection off? That's the only thing left that I can think of. Thanks.

 

[cr2k]

Re: 2 stroke oil blockage in head or exhaust?

I am just guessing, but what is the fuel/oil ratio you are using? go to 50/1 with a QUALITY TW3 or 4 oil. Not cheepo crap. What kind/brand of oil? Have you tried new spark plugs? Also you may try some decarbonizing cleaner. How old is your gas? You may also have some blockage in your high speed circuit in your carb.

 

[James R]

Re: 2 stroke oil blockage in head or exhaust?

If the thermostat is missing or wide open the motor could be running too cold. This can contribute to fuel not burning correctly and burning the oil off. Don't use anything but regular gas as using high octane does not burn as readily.
cr2ks comment is very valid. Also if you are running with an overly rich mixture this can cause oil build up. I have used Penzoil Synthetic Blend 2 stroke oil on all my motors for some years and get clean running with less smoke.

 

[ba_50]

Re: 2 stroke oil blockage in head or exhaust?

It has a new thermostat and plugs. I use 50/1 Johnson TC-w3, sea foam, and the enzyme stuff in fresh gas.
I haven't checked the reed valves as it might need a special tool on the bottom bolts. The mechanic thought is was running rich but hasn't been back.

I don't believe it is the carb.

I do know that a plugged exhaust can cause loss of power or none at all. All the other usual stuff has been checked.

 

[steelespike]

Re: 2 stroke oil blockage in head or exhaust?

Is the link and sync set right?Stator advancing and throttle plate opening?
Good strong spark? If the reeds were bad it is likely you would see puffing/spitting out the carb.
If you pull the plugs and crank it over you should feel the crankcase compression and a little puck puck noise.

 

[ba_50]

Re: 2 stroke oil blockage in head or exhaust?

The mechanic said the linkage was adjusted right and it sounded like it was running too rich. If it isn't the fuel pump and carb than the plugged exhaust is about the only thing left. There is a small tube along side the exhaust tube. Guess I'll take the lower unit off and see if I can flush it out.

Another poster with a '97 9.9 had a similiar problem and it was a power pack and maybe a stator. Guess I may have to buy a DVA adapter for 2 motors since I don't think the mechanic is coming back.

UPDATE;

A picture of the exhaust shows a big enough opening to the muffler that just cleaning the holes should be enough.