Yamaha experts, tackle this one?????

[ocean goin]

I have a 93 yamaha 200 model 200TXRR and it started making a real nasty rattle from the power head at idle. It seems to run fine at 3000-3700, anything over that and it starts to missfire, I'm thinking a loose conecting rod end, any tests I can do to eliminate the obvious???

 

[12Footer]

Re: Yamaha experts, tackle this one?????

Compression test should reveal the problem.<br />It could be a broken reed, wrist pin, spun main bearing, broken ring, holy piston, or wallered cap bearing.<br />After the compression test, I would pull the head, and examine the bores. That being in good shape, i would pull the reed box, examine the reeds, crankshaft and mains.<br /><br />I've heard of sound deadening material under the cowling werking loose on a motor, contacting the flywheel, and creating a racket. The owner easily fixed it with a good tug.<br />Good luck.

 

[ocean goin]

Re: Yamaha experts, tackle this one?????

thanx 12 footer, I forgot to mention that just before this noise grief the prop got wrapped up in a lobster line and stalled the engine.

 

[ocean goin]

Re: Yamaha experts, tackle this one?????

I appreciate the reply 12 footer. Comp. is 110-115 in all cylinders so I'll attempt pulling the the intake and reed plate tomorrow. Might you have any other advice???? I have rebuilt many truck motors but this is the first boat motor and yes I do have a clymer which is okay but not what I would like to have.

 

[DJ]

Re: Yamaha experts, tackle this one?????

Ocean,<br /><br />Did you check to see if the flywheel is tight? Key sheared-maybe?

 

[ocean goin]

Re: Yamaha experts, tackle this one?????

I checked the timeing on each cyl. with the TDC mark for each one and they were dead on so I figured the flywheel was okay I also thought that the half moon might have sheared when I got tangled in the rope and it possibly threw out the timeing, I was at idle and in gear when I hit the rope, it stalled the engine and I tryed to start it twice before I new I was hung up.

 

[ocean goin]

Re: Yamaha experts, tackle this one?????

sounds like rip and tear

 

[Walker]

Re: Yamaha experts, tackle this one?????

Could the noise be coming from the lower unit? I'd drop the L/U and put a water hose on the down tube in the midsection and fire the motor up. A 5/8" water hose with no end will slip right over most down tubes

 

[ocean goin]

Re: Yamaha experts, tackle this one?????

T hanx Walker, I tryed that and the nasty grumbleing rattle is up top so I figure I'll pull the intake and reeds then have a peak

 

[denniz]

Re: Yamaha experts, tackle this one?????

Im not a Yamaha expert, i hate working on the damn things. But ive heard oxygen sensors rattle so bad that I thought it was a rod knocking. (no pun intended) Its on the starboard side of the block top cylinder. There is a service bulletin on a part change to some motors but im not sure which ones were affected. Call Yamaha tech service, or try them online. Those guys are great, really helpful.

 

[ocean goin]

Re: Yamaha experts, tackle this one?????

did they put an oxygen sensor on a 2 stroke in 93??

 

[KNOTTY THOTS]

Re: Yamaha experts, tackle this one?????

Ocean, I was hoped I'd fine an answer on this one as I have the same problem. Sounds like the the rods or tapets on a four stroke wearing out. Mine is on the lower left side behind the oil pump. Did you ever get this fixed.