Yamaha 50 squeak/chirp noise

[ATeFFT22]

well here it is, I just bought a use 98 yamaha 50 hmhos 2-stroke and I have a occasional loud squeak/chirp noise coming from it. I have located the general area the noise originates and it is where the propeller shaft goes from powerhead to the leg. here is a video of the noise. I am fearing that it is a bearing on the bottom of the crank. I have pulled and lubed the prop shaft and i still get the squeak. Please view teh youtube video and give me your thoughts.

http://www.youtube.com/watch?v=xgzFCc4dA9c

Thanks, andy

 

[deejaycee_2000]

Re: Yamaha 50 squeak/chirp noise

Welcome to the forum Andy .... glad to see you are here also ... haha

you will have to strip ..... and run that motor on pre-mix ... disconnect that oil injection ....

 

[Ray Neudecker]

Re: Yamaha 50 squeak/chirp noise

Often this is from a bad upper crank bearing seal.

 

[ATeFFT22]

Re: Yamaha 50 squeak/chirp noise

Thanks DJ, I lurk alot of these forums Again I believe the noise is coming from a lower crank seal or bearing. closest I could pinpoint noise is just below powerhead where prop shaft goes into crank. Ok DJ I am Now Planning on switching to pre-mix, but I just want to get this resolved before I start fishing with this can of worms HAHA.... Thanks for help guys.

 

[ATeFFT22]

Re: Yamaha 50 squeak/chirp noise

So the following is the fix that seems to have worked for me. Was posted by a member of another site that I frequent. I adjusted the Air/fuel mixture, and to my disbelief that appears to have solved the noise. Thanks to all who have viewed or posted suggestions to this thread.




"It's what you call a "lean sneeze". It could come from a couple of places. Carbs may have a blockage in the idle mix area. Check the jets, strip and clean the carb. check the plastic rubbers. If the carbs are good then you need to look at the seals and any other place air can get in and change the mix. Check the airscrew is +-5 half turns (obvious first choice)."

Have experienced the same problem on my Yammie when I used to race.

 

[deejaycee_2000]

Re: Yamaha 50 squeak/chirp noise

hehe, especially when you have any motor on a t-cat it is better to disconnect the oil injection .... as you would know it is always a wet ride ... and water and oil injection don't go well together ......

 

[rodbolt]

Re: Yamaha 50 squeak/chirp noise

hahahah
you guys are funny.
why not simply do the maint on a proven reliable oiling system and enjoy boating?
most likly that chirp is a lean sneeze unless the bottom main is failing, if its failing no amount of premixing will help.

 

[drewmitch44]

Re: Yamaha 50 squeak/chirp noise

HAHAHA rod is right! Why dont you guys just spray wd-40 on the problem and hope it fixes it! If wd dosent do it then well it might be time for the PB Blaster penitrating oil to get the chirp out of there! I agree with rodbolt. Why not just get the motor running the way it is supposed too and then go from there? That way you are not making a motor that is rigged all up with crap that you have to do to maintain it. You have to add in the normal maintnence book that "every 3rd outing you have to spray the lower bushing with WD". LOL you are adding that to a yamaha and its not right!

 

[drewmitch44]

Re: Yamaha 50 squeak/chirp noise

I had a ...... rigging in the last sentance and that would not be right!

 

[drewmitch44]

Re: Yamaha 50 squeak/chirp noise

Id test compression i sounds like you can hear a chunk of metal every time it chirps! Chirp and at the same time the idel goes down. Something somewhere is rubbing when the chirp happens and it causes the motor to down idle like it hit something! It would worry me!

 

[rodbolt]

Re: Yamaha 50 squeak/chirp noise

actually a lean sneeze can make it chirp. not so bad on the yamahas but a suzuki will sound like a cricket.
but do the maint on the precision blend and it works well for years and years.
usually a failed bottom main sounds like marbles in a tin can.

 

[ianyoung77]

Re: Yamaha 50 squeak/chirp noise

This is a very interesting thread since I have a 50Hp Yamaha doing exactly the same thing. Was this ever resolved?

On my motor the squeak does sound quite metallic so I was obviously concerned about oil. I ran the motor on premix and checked the oil flow at 1500rpm and it was fine. I then left the motor running on premix with the injection still connected and the squeak was still present.

Since it seemed to not be the pistons causing the squeak I cleaned the whole fuel system and played with the air mix but this is extremely difficult to set when the squeak is present as it will stall the motor at low revs. One of the posts mentioned air getting into the fuel system. Is there an easy way to check for this? I must say though the noise sounds more like a squeak than a sneeze.

Other posts mentioned a bearing problem. Is there a way to check this short of pulling down the whole motor? Someone mentioned WD40. Where would you spray that to check a bearing?