boatmon345
Petty Officer 2nd Class
- Joined
- Apr 26, 2006
- Messages
- 113
My 1997 Yamaha 150 carbed 2 stroke S150TXRV seems to be doing well after the rebuild about 30 hours ago, except for what I am about to describe.
There is one issue that makes me nervous, and this was happening before the rebuild too. It has always happened for the two years I have owned the engine. Perhaps it is normal but I have to ask.
The engine gets very "loud" which onsets from about 3600 RPM and eventually gets back to its normal sound - quiet - around 4100 RPM. I cannot imagine what this noise is. Don't know if it is knock, or what.
Ray, in a post to someone's issue you made recently you mentioned something about timeing being wide-open but fuel not yet wide open. Could this be what is happening - timing too advanced for the speed of the engine?
I do not like to run the engine in this range. I run at 3400-3500 usually, and if have to go faster I get above 4100 quickly. I do not mind the noise, but It sounds like the engine is going to fly to pieces If I stay there. With a full load of guests, though, sometimes I am forced to put the engine into this range, to maintain plane.
When my engine was rebuilt, 3 rods were replaced and the crank was replaced (all used), FWIW.
Those of you who have dealt with engines of this size, have you noticed this very loud operation too during a certain RPM range, or is it just me?
Thank you very much.
There is one issue that makes me nervous, and this was happening before the rebuild too. It has always happened for the two years I have owned the engine. Perhaps it is normal but I have to ask.
The engine gets very "loud" which onsets from about 3600 RPM and eventually gets back to its normal sound - quiet - around 4100 RPM. I cannot imagine what this noise is. Don't know if it is knock, or what.
Ray, in a post to someone's issue you made recently you mentioned something about timeing being wide-open but fuel not yet wide open. Could this be what is happening - timing too advanced for the speed of the engine?
I do not like to run the engine in this range. I run at 3400-3500 usually, and if have to go faster I get above 4100 quickly. I do not mind the noise, but It sounds like the engine is going to fly to pieces If I stay there. With a full load of guests, though, sometimes I am forced to put the engine into this range, to maintain plane.
When my engine was rebuilt, 3 rods were replaced and the crank was replaced (all used), FWIW.
Those of you who have dealt with engines of this size, have you noticed this very loud operation too during a certain RPM range, or is it just me?
Thank you very much.