Merc 200 efi vibration

[elpez]

I'm running a 200 efi merc on my 21 1998 seacraft, the noise and vibration is too much, after 2-3 hours on the boay I'm ready to swim home. Its worse at 3500- 4000 rpm but noticeable at idle too, engine readily revs up to 4800 without problem and boat planes quickly. Any suggestions??

[pogden]

If it is idleing smooth and runs clean it is probably not the plugs or timing. It would probably be drive train related either prop or drive shaft. I would suspect prop.
Maybe someone else has a suggestion.

[gw204]

If 4800 is the highest it will rev, you're overpropped. That motor should spin to 5800. Drop down at least 3" in pitch to get the revs up and see if that corrects the problem.

If 4800 is WOT right now, you've been lugging it and probably have some significant carbon build up inside the motor. Begin adding either Merc's Quickleen or Yamaha Ring-Free to get rid of the carbon and go easy on it for a while.

Run a compression check to see if you possibly have some internal engine problems.

Good luck.

[JohnB]

Check that all the plugs are firing, there may be one that is fouled or not firing, and this would cause you not to get to WOT, and also vibrate alot.

[elpez]

Thanks for your advice and suggestions!! cyl #1 has low compression, mechanic suggested a 225 yamaha 4 stroke as the cure, anything else would be an expensive remedy. [img]/images/graemlins/frown.gif[/img]
any thoughts on a suzuki vs a yamaha 4 stroke, or a 200 yamaha HDPI??

[gw204]

mechanic suggested a 225 yamaha 4 stroke as the cure, anything else would be an expensive remedy.

Does he think a F225 is not an expensive remedy??????

A new powerhead for your motor will be $4K max + installation. You should be on the water again for around $5K. The 200 EFI Merc is a good engine if you take care of it. Switch manufacturers and you have another $1K in swapping controls, gauges, etc. to contend with.

It all depends on how much you want to spend. [img]/images/graemlins/smile.gif[/img]

FYI - You can get left over 2-stroke Suzuki 225 V6s w/ controls for under $8K. Search classicmako.com for the place offering them.

[Ryan]

From what ive heard the suzukis are great, but i dont have any first hand expirience with em you should also post this question on thehulltruth or florida sportsman

[elpez]

Yes the f225 will be expensive but a permanent solution, the 5k I spend now may be good for 2-3 years and then I'm back where I am today. my last engine (mariner 150 carb, 1988) is still going strong, but was never apart, I've found out this particular engine has a "troubled" history. Will look for a leftover suzuki or yamaha.