It is always something. My latest problem with old Yanmar(YSM12) is that after slowing to idle speed, it will not speed back up. Seems to be stuck at quarter throttle. If I take it out of gear and advance throttle, after a period of time it seems to take off again. Any ideas?
Won't speed up
- Thread starter Butch Beard
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Check Throttle Linkage
Sounds like a cable problem, when you increase the throttle does the linkage arm on the motor move to correspond with the throttle.
Sounds like a cable problem, when you increase the throttle does the linkage arm on the motor move to correspond with the throttle.
Exhaust Manifold
Hi Butch, Check exhaust for restrictions and also remove air cleaner just to elimate it. Doesn;t sound like an air cleaner. The exhaust manifold surface gets coated over time. Will need to disconnect the exhaust manifold to see if it's restricted. Remotely possible it's the governor. From the way you describe the engine revovery - points more to exhaust. Good Luck,
Hi Butch, Check exhaust for restrictions and also remove air cleaner just to elimate it. Doesn;t sound like an air cleaner. The exhaust manifold surface gets coated over time. Will need to disconnect the exhaust manifold to see if it's restricted. Remotely possible it's the governor. From the way you describe the engine revovery - points more to exhaust. Good Luck,
Toilet paper clog?
Hey, if you ask questions in the marine sanitation forum, you're gonna get marine sanitation answers!
Hey, if you ask questions in the marine sanitation forum, you're gonna get marine sanitation answers!
Fluid Ejaculation..
..look at the exhaust..is there plenty of fluid (hopefully its water) flowing out?If so,your problem is elsewhere..look at the shift box and cable asssembly..if all that checks out think engine problem.Get out your Yanmar Service Manual (you do have one of those,right??!!) and start trouble shooting..it'll be process of elimination.One more thing..check for air at the injectors..a loose fotting letting in air will cause similiar action from a Diesel..do a quick bleed just to be sure then run and see if its better..if so,you know the problem is in that system.If not,move on. Good Luck and Fair Winds>>> David
..look at the exhaust..is there plenty of fluid (hopefully its water) flowing out?If so,your problem is elsewhere..look at the shift box and cable asssembly..if all that checks out think engine problem.Get out your Yanmar Service Manual (you do have one of those,right??!!) and start trouble shooting..it'll be process of elimination.One more thing..check for air at the injectors..a loose fotting letting in air will cause similiar action from a Diesel..do a quick bleed just to be sure then run and see if its better..if so,you know the problem is in that system.If not,move on. Good Luck and Fair Winds>>> David
Need for speed
I'd also venture a guess at the speed governor. Some questions that may help someone come up with an answer - Has it been a while since you replaced the fuel filter(s)? How old is the fuel? Any sign of the engine overheating before dropping it back to idle? Any belt squealing sounds or loud bearing noises coming from the engine? Any unusual vibration when the engine is in gear and up to speed? Any chance the prop is fouled with line or barnacles? Manny
I'd also venture a guess at the speed governor. Some questions that may help someone come up with an answer - Has it been a while since you replaced the fuel filter(s)? How old is the fuel? Any sign of the engine overheating before dropping it back to idle? Any belt squealing sounds or loud bearing noises coming from the engine? Any unusual vibration when the engine is in gear and up to speed? Any chance the prop is fouled with line or barnacles? Manny
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