Hey,
This is my first post here (just bought used yamaha) but all the googling I did directed me here, so here it goes. I recently purchased a used 1544 Cajun Special with a 1998 Yamaha 40hp with remote controls. The engine runs very smooth (much more so than the evinrude I had before). However, sometimes after running on plane for a couple minutes, the engine begins to lose power gradually. It is a smooth transition. There is no sudden slow down or anything like that. It does this pretty consistently. Every once in a while though, the engine will run, say, all the way back to the landing, no problem. I dont have a tach on the boat, but I never run all the way open. The tell tale is spitting water and the overheat alarm does not go off. When this happens, I can throttle down to idel for a second and then gun it again and it takes off. Also, sometimes after I have had it off for awhile fishing (not long enough to seem to need a cold start), when I start the motor, it idels high for a second, drops down (seems normal) but then it does something which Ive never had happend before. A (hard to explain) sort of spitting or hissing (short and cutoff, almost like a softer doe snort) happens a couple times and the engine dies. The noise seems to be coming from the upper exhaust port. This will happen several times, but I can get it too go by very quickly putting it in gear (forward idle not enough, have to go further). A couple times it has made the noise that concerns me most after doing this acouple times. It spits out of the exhaust a couple times like explained above, and then it will make a high pitched noise and immediately die. The noise is kinda like an air horn, but not as loud and a tad more shrill. From what I have read, it seems like a fuel pressure or carb issue, but the noises are what concerns me, hence the post. You guys seem to be the most recommeded for yamaha issues, so any insight you could give me would be greatly appreciated. Thanks in advance for any help.
This is my first post here (just bought used yamaha) but all the googling I did directed me here, so here it goes. I recently purchased a used 1544 Cajun Special with a 1998 Yamaha 40hp with remote controls. The engine runs very smooth (much more so than the evinrude I had before). However, sometimes after running on plane for a couple minutes, the engine begins to lose power gradually. It is a smooth transition. There is no sudden slow down or anything like that. It does this pretty consistently. Every once in a while though, the engine will run, say, all the way back to the landing, no problem. I dont have a tach on the boat, but I never run all the way open. The tell tale is spitting water and the overheat alarm does not go off. When this happens, I can throttle down to idel for a second and then gun it again and it takes off. Also, sometimes after I have had it off for awhile fishing (not long enough to seem to need a cold start), when I start the motor, it idels high for a second, drops down (seems normal) but then it does something which Ive never had happend before. A (hard to explain) sort of spitting or hissing (short and cutoff, almost like a softer doe snort) happens a couple times and the engine dies. The noise seems to be coming from the upper exhaust port. This will happen several times, but I can get it too go by very quickly putting it in gear (forward idle not enough, have to go further). A couple times it has made the noise that concerns me most after doing this acouple times. It spits out of the exhaust a couple times like explained above, and then it will make a high pitched noise and immediately die. The noise is kinda like an air horn, but not as loud and a tad more shrill. From what I have read, it seems like a fuel pressure or carb issue, but the noises are what concerns me, hence the post. You guys seem to be the most recommeded for yamaha issues, so any insight you could give me would be greatly appreciated. Thanks in advance for any help.