Saltwater Intrusion Into 1 or More Cylinders 1997 Yamaha 150 S150TXRV

[jasonalden]

Re: Saltwater Intrusion Into 1 or More Cylinders 1997 Yamaha 150 S150TXRV

Rodbolt, referring to the diagram of my eng here <br />Power Head Diagram, can I pull off #15 (the cylinder block/crankcase cover) without removing the flywheel/upper crankshaft hardware (#6,7,8).<br /><br />Also, can I pull off #15 without first removing the carbs? It seems like I should be able to. I don't see a reason to remove the carbs unless you say I have to...<br /><br />Thanks.

 

[Ray Neudecker]

Re: Saltwater Intrusion Into 1 or More Cylinders 1997 Yamaha 150 S150TXRV

You will have to pull the power head off, remove the flywheel and electronics, remove the top main bearing or at least the top two bolts and pull at least two bolts from the bottom cap and crankseal holder to seperate the front half from the block. You can pull the entire intake with carbs as a unit. Many times I do this just to make it easier to keep up with all of the parts. Even so the carbs need to be gone through as part of the rebuild and you will have to unmount them to do so. A whole lot easier pulling and remounting while the intake is laying on a table than mounted to the powerhead. Many times the problem if caused by a fuel restriction or bad fuel does not damage the major expense items such as the crank. The block can most often be repaired. Letting it sit with the possibility of water being in it can cost big bucks for bearings and crank.

 

[jasonalden]

Re: Saltwater Intrusion Into 1 or More Cylinders 1997 Yamaha 150 S150TXRV

OK thanks Ray. I was afraid of that.

 

[jasonalden]

Re: Saltwater Intrusion Into 1 or More Cylinders 1997 Yamaha 150 S150TXRV

Rodbolt & Ray, you guys would be proud of me. I dove into this head first today and made good progress.<br /><br />See here for the update with pictures & a video:<br />Update <br /><br />Do I need to buy the flywheel removal tool or can I make something out of bolts and a vice grip to pull it off???<br /><br />Anyone know how many pounds my powerhead alone is? I have to figure out how to hoist it off the mount.

 

[Ray Neudecker]

Re: Saltwater Intrusion Into 1 or More Cylinders 1997 Yamaha 150 S150TXRV

You will need a flywheel puller. A universal type will work fine. Use the head bolts to attach it and discard after using. Be careful not to run them so deep you hit the stator.<br /> The powerhead complete is about 150 lbs. the crank bearing being down is normally caused by a restrition in the oil line to that cylinder. You will have to replace that rod and crank or have the crank remanned. Boring the cylinder may clean it up. you will need to check with a machine shop for advise on this.

 

[jasonalden]

Re: Saltwater Intrusion Into 1 or More Cylinders 1997 Yamaha 150 S150TXRV

Ray, are you saying discard the head bolts after using them to remove the flywheel? If so, why? Am I suppose to replace bolts during assembly?

 

[Ray Neudecker]

Re: Saltwater Intrusion Into 1 or More Cylinders 1997 Yamaha 150 S150TXRV

Discard because you will stretch or bend them in the process. Yiu can keep them with the puller to reuse. Do not put them back in the block. Can create lots of problems. Be awful easy to break off while torquing.

 

[jasonalden]

Re: Saltwater Intrusion Into 1 or More Cylinders 1997 Yamaha 150 S150TXRV

Thanks, understood.<br /><br />A couple more questions:<br /><br />1) I read in the manual that if the crank is scored to REPLACE it as during the manufacturing of the crank, the hardening process makes it so the crank can't (or shouldn't) be resurfaced. Specifically:<br />"The hardening process used does not allow for machining of the crankshaft."<br />Question: <br />Do marine mechanics resurface cranks, regardless of this statement in the manual? In other words, as professionals with the extensive experiece that they have, how critical is this?<br /><br />2) Looking over the tolerances for the internal parts, I see that the limits are such a minimal amount (a half-tenth of a millimeter for head to block surface variation, for example). Does this really impact engine operation/life? What do mechanics do...Do they measuring of every single component, pin, etc. or based on experience or is some of this considered not so critical?<br /><br />Bottom line: Should I follow the manual exactly, or are some steps overkill.