Yanmar Engine Vibration

kloudie1 · Oct 2, 2016

May be a dirty injector? Do the final bleed while running.. If you note a difference in how the engine runs while you have one or the other injector bleeding.. that cylinder should miss.. if one misses much stronger than the other, then the one that causes the least miss when bleeding is the one that needs attention.

Benny17441 · Oct 2, 2016

It all boils down to the degree of vibration. Yes, any vibration can be corrected but the fix can be costly ($$$). It can be expected on a 25 year old boat to experience some degree of vibration but it should not be an exaggerated hull and engine shaking experience. A minor vibration can be tolerated and by learning at what RPM range the vibration is least evident we can learn how to use the engine and postpone costly repairs for perhaps another 10 years. The main cause for engine vibration are; worn or broken motor mounts, uneven compression between cylinders (worn rings, valve seats, valve springs) , fouled injectors, poor engine alignment, incorrect valve lash adjustment, fouled prop and driveshaft. These small two cylinder engines have an inherent vibration even when new which is tamed by strong motor mounts, drive train balance and engine alignment. I would not think it is the fuel unless the engine is running erratically.

Ralph Johnstone · Oct 2, 2016

kiteflyer said:
But I noticed that the engine has been vibrating quite a bit more than I'd like.

Is this in or out of gear ? As a first test, see how the engine runs in neutral. This will eliminate problems external to the engine.

AWW · Oct 3, 2016

Vibration and white smoke as engine RPM is increased can be caused by over-filling the engine oil - check your oil level to determine if it is over-filled. Another cause, while in gear, can be a worn cone in the transmission. Usually the vibration will cease very quickly if engine power is increased and the transmission locks. You won't get the vibration in neutral and you may not get the vibration in reverse. Vibration can also be caused by too much oil in the transmission which prevents the cone from seating properly and the engine will shake on its mounts as a result. Again, check the level of oil in the transmission. The correct fill level is usually very low on the dip stick.

Dan Hill · Oct 3, 2016

As a mechanic by trade, I have learned to always start my diagnostics by looking at the most recent repair(s). A misfire or cylinder imbalance on any diesel is most likely injector related. Considering you just serviced the fuel system I would defiantly start there. Just a very small partial could have gotten through or was dislodged during your service work and could cause your issues with vibrations and smoke. As people eluded to above, test while running to isolate which cylinder. You only have 2 so it should be easy. My 2¢. Good luck with your search.

Dan

spadaforaj · May 28, 2025

Thanks - I have the similar problem =- I just paid $$$$$ to have my injectors serviced. So, while in idle and with increasing RPM , it vibrates so much more than before - and I mean alot. I have not even put it into gear for fear of what might happen - any advice on talking with to the people who did the injectors ?

Ralph Johnstone · May 28, 2025

spadaforaj said:
any advice on talking with to the people who did the injectors ?

You are responding to a nine years old posting. My advice would be to re-post your question with as much detail as possible.

If you're interested in solving your problem, we're interested in helping you.

kappykaplan · May 28, 2025

Ralph Johnstone said:
You are responding to a nine years old posting. My advice would be to re-post your question with as much detail as possible.