planetexpress
Recruit
- Joined
- Apr 9, 2007
- Messages
- 5
I figure I'll ask on here to see if anyone has had this problem with a 2 stroke outboard. This shouldn't be specific to Tohatsus:
My Tohatsu 5HP, 2 stroke outboard has a vexing problem. It starts right up and develops good power for approx the first minute or two of operation, until the outboard warms up. After this time, the outboard produces somewhere around 1/2-3/4 of the normal power it would produce.
You can run it for an hour, but as long as it's warm, it produces 1/2-3/4 of the power it does when it's cold.
If I drop the dinghy at a dock for a few hours and start it from cold again, the normal power returns. Any time the engine is cold, it runs perfectly. Any time it's warm, it gets sluggish.
Things I know:
Impeller is producing a good jet of water and cooling the engine (it isn't heating up or producing any temps inside the housing)
Lower unit gear oil was replaced this spring, as normal.
Spark plug was replaced a few minutes ago as a possible root to the problem. That didn't change the behavior of the outboard.
Fuel isn't an issue since it has been doing this on more than one tank of fuel. I've burned 2 tanks of different fuel with the same results.
Thinking outside the box:
Is it possible that my rings are shot or something? I mean those things expand when heated (or the cylinder does), which may make some spacing issues as the engine is warm that don't take place when cold, right? Just grasping at straws here. I'm not quite sure what to start looking at next.
My Tohatsu 5HP, 2 stroke outboard has a vexing problem. It starts right up and develops good power for approx the first minute or two of operation, until the outboard warms up. After this time, the outboard produces somewhere around 1/2-3/4 of the normal power it would produce.
You can run it for an hour, but as long as it's warm, it produces 1/2-3/4 of the power it does when it's cold.
If I drop the dinghy at a dock for a few hours and start it from cold again, the normal power returns. Any time the engine is cold, it runs perfectly. Any time it's warm, it gets sluggish.
Things I know:
Impeller is producing a good jet of water and cooling the engine (it isn't heating up or producing any temps inside the housing)
Lower unit gear oil was replaced this spring, as normal.
Spark plug was replaced a few minutes ago as a possible root to the problem. That didn't change the behavior of the outboard.
Fuel isn't an issue since it has been doing this on more than one tank of fuel. I've burned 2 tanks of different fuel with the same results.
Thinking outside the box:
Is it possible that my rings are shot or something? I mean those things expand when heated (or the cylinder does), which may make some spacing issues as the engine is warm that don't take place when cold, right? Just grasping at straws here. I'm not quite sure what to start looking at next.
