Need some pure speculation

[numlaar]

Hey all,

Num here .. been a little while... I need some purely speculative advice...

As some of you know, I re-powered my Xscape with a 1994 200HP Evinrude...

I just got the "spring checkup" report from the shop on it, and they are telling me that the motor has a "knock"
 in it... now its nothing that I can hear myself... (I am VERY technically inclined, and was a master auto tech for 10 years) I usually can hear an engine noise...

That being said, they think its on #3, and they said the knock gets louder when they disconnect the spark plug with the engine running, so they think its a wrist pin on that cylinder going bad.

Now, before I got this motor, I have no idea how long it sat, and also before I got the motor, the carbs were full of 2-stroke oil... before I started it initially, I did spray lube in from the front, and into the cylinders, let it sit for a week, and turned it over by hand. But it very well could have had some rust build-up on the crank/rods/ etc. that I wasnt aware of...

The mechanic there, said it could work like this for 2 months, or 2 years, there is no way to know... and he suggested I just run it until it goes.. (it does run just fine by the way)

I hands down can not afford to buy another engine... so my question is, what do you all think?

• Should I tear it down NOW and rebuild it (would cost me the gaskets, bearings, rings) me doing all the labor, (But cost me the summer boating season AGAIN!)
  
• or can I wait for this season, and re-build it in the winter,
  
• or should i follow his advice, and just run it till it goes, then re-build it then? (seems to me that would cost more because it could damage the block/piston??)

Any thoughts?

[Capt. Bob]

I think you already got all the pure speculation you need already from your mechanic.

I'll vote to run it and monitor.

[numlaar]

I think you already got all the pure speculation you need already from your mechanic.

I'll vote to run it and monitor.

hehe thats true Bob... but its always nice to have some additional votes on what to do.

Thanks for the feedback!

[CLM65]

I will also vote to run/monitor with the following caveats:

1.  I would only run it for this boating season, and rebuild it over the winter.  I agree that running it to failure will likely result in a more costly repair.

2.  Re-assess your schedule for a rebuild now.  I've never rebuilt an engine, but will it really take all summer to rebuild it?  It is mid-late March now...could it be done by June?  Of course, this is coming from the guy who has taken over 2 years rebuilding a boat, and still doesn't have much to show for it....

[numlaar]

I will also vote to run/monitor with the following caveats:

1.  I would only run it for this boating season, and rebuild it over the winter.  I agree that running it to failure will likely result in a more costly repair.

2.  Re-assess your schedule for a rebuild now.  I've never rebuilt an engine, but will it really take all summer to rebuild it?  It is mid-late March now...could it be done by June?  Of course, this is coming from the guy who has taken over 2 years rebuilding a boat, and still doesn't have much to show for it....

Sadly i just took on a project to build a cottage... i could realistically rebuild the engine in a weekend... i've done it before with a crossflow... but i have never tried on a looper. Same basic principles though.. but the crossflow i had apart many times... so all of the bolts were already undone, and lubed, etc. I have never had this motor apart.. so I would imagine having to deal with seized bolts, etc. too many unknowns, so would anticipate at least a month of weekends minimum. most likely with my schedule that would end up smack in the middle of summer... and with my luck would go bad, and then be down another boating season lol

[fitz73222]

Hi numlaar,
Since you are an auto mechanic, verify what this guy is telling you with your stethoscope. It's easy to check for a wrist pin issue. Roll the engine over to TDC then about 1 degree past. Take a screwdriver through the plug hole and push on the piston and see if you can feel any clearance issues. It will click or knock. This can also give you a rod bearing check. Whats weird to me is that the wrist pin should quiet down with spark plug wire off. Check the base idle timing to make sure its not overadvanced. I look at it this way if YOU can't hear it it's not that bad. I have run lots of engines in my time with plenty of rattles and tics without any issues. Just run it and keep your ear open.

[Thunderyacht]

I say run it til it goes Tango Uniform. Either way, tear it down now or wait til it's toast, you were looking at a big bill. Maybe the mechanic had his old Timex near the scope and that's the ticking/knock he heard and you'll get 800 more hours out of it. Or, he was correct and you get 50, either way you were looking at bucks or time or both.  I say run it like you stole it.  :-)

[numlaar]

I say run it til it goes Tango Uniform. Either way, tear it down now or wait til it's toast, you were looking at a big bill. Maybe the mechanic had his old Timex near the scope and that's the ticking/knock he heard and you'll get 800 more hours out of it. Or, he was correct and you get 50, either way you were looking at bucks or time or both.  I say run it like you stole it.  :-)

heheh sounds good. I am going to add an hours meter to it now (never had one before), and see how much time I really get out of it.