One of our Yamaha 150’s has a miss at idle. The engines are on a GW Freedom 255. Could it be plugs or fuel filter?
150 hp Yamaha has miss. Fuel filter or plugs?
- Thread starter Craig
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Bloodweiser
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Plugs were changed at last 100hr. I will get a filter and plugs before I remove cowling
Bloodweiser
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Need more info. Year of engine? # hours? Runs OK at higher RPM? If really a miss, is it consistent? Fuel problems typically reveal themselves at higher RPMs. Check plugs for fouling. Clogged or bad injector could cause a "miss," but would most likely be there at all RPM ranges. Ignition problem could be plug or coil, depending on the engine, coils feed two plugs. Bad/loose plug wires? Lots of possibilities! I always recommend you get the Yamaha YDIS diagnostic software/cable if your engine is compatible.
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Bloodweiser
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Have you checked this ?Need more info. Year of engine? # hours? Runs OK at higher RPM? If really a miss, is it consistent? Fuel problems typically reveal themselves at higher RPMs. Check plugs for fouling. Clogged or bad injector could cause a "miss," but would most likely be there at all RPM ranges. Ignition problem could be plug or coil, depending on the engine, coils feed two plugs. Bad/loose plug wires? Lots of possibilities! I always recommend you get the Yamaha YDIS diagnostic software/cable if your engine is compatible.
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could be a lot of things. Best move is to have codes dumped. That said, the first thing I would look at are the plug wires to make sure they are seated correctly Does the miss occur on a cold start and after warming up?
Could be a bad plug, coil or injector. You can also try pulling plug wires one at a time and starting the motor to see if the miss gets worse. That should determine if the problem is a specific cylinder or common to all.
Could be a bad plug, coil or injector. You can also try pulling plug wires one at a time and starting the motor to see if the miss gets worse. That should determine if the problem is a specific cylinder or common to all.
Boat and engines purchased new in October 2017. I trimmed good engine out of the water. Problem engine had miss and didn't develop full power through full throttle range.
I will try to get into shop tomorrow.
If there were a fuel restriction, you would expect the motor if it runs, to run better at low revs and no load. Since yours runs crappy at all speeds, I would be less likely to suspect a fuel problem
Were the plug wires loose? I would not expect multiple plugs to go bad unless there is another factor. I assume both motors were serviced at the same time and therefore if it was just aging plugs, you will should see a similar problem on the other motor.
How did the plugs look?
How did the plugs look?
Both set of plugs were replaced in September 2019. These plugs looked ok, but one obviously had a internal issue. Boat runs great now!
A single bad plug I can understand.
It isn't all that often that fixes are that simple and inexpensive!
The boating gods have smiled on you
It isn't all that often that fixes are that simple and inexpensive!
The boating gods have smiled on you