What got in the cylinder

[Monte1961]

Re: What got in the cylinder

LMAO I couldn't help myself by asking that! I'll be over in my corner giving myself a timeout!

 

[snagalager]

Re: What got in the cylinder

Dont tell me.. + 0r - 0 would be the lowest. lol...

 

[fireman57]

Re: What got in the cylinder

snag the rule of thumb is if they are within 10% of each other you are okay. I wouldn't want them below 50 personally.

 

[snagalager]

Re: What got in the cylinder

What I was getting at was. If I put rings only on the bad piston..is that cylinder gonna read the same as the other three that are at 90 or so psi. Or am I going to get a much higher reading with the new rings on one piston and need to do them all anyways?

 

[scanman]

Re: What got in the cylinder

If ya gotta tear it down, I'd go with all new rings & have the block honed or bored as necessary to get all four in the same +/- 10% range. I agree that 50-60psi would be the lowest. Do the block first & the machine shop will tell ya what rings to buy. They all need to be pretty close to the same psi, or you'll cause other problems later, cause it'll be outta balance. That'll wear seals, rod bearings, & crank journals.

 

[levi_tsk]

Re: What got in the cylinder

http://cgi.ebay.com/ebaymotors/John...5045366QQptZBoatQ5fPartsQ5fAccessoriesQ5fGear

 

[emdsapmgr]

Re: What got in the cylinder

At a minimum, you will be looking at a complete teardown. 3 new standard ringsets. One new piston and ringset-either standard bore or oversize, depending on how bad the cylinder walls are. The cyl heads changed on that engine midyear. The early heads were 528/529 heads: the compression will run 125 when overhauled. Your engine has the later heads-the low compression 504/505 bathtub heads. Your will compression will run at least 15 lbs less after overhaul.

 

[1946Zephyr]

Re: What got in the cylinder

Shoot, I get 120 psi on a 52 year old 35 and that's with a hand starter. I hope they're more than 90 psi. >

 

[snagalager]

Re: What got in the cylinder

Here it is. My bad luck. Got the motor all broke down. Found broken rings on the bad piston and wear marks on the other cylinders. The center main bearings fell out of their retainers. Also found a bolt that holds the crank case together had backed out and was touching the reed block flaps. Checked on prices for all parts, boring, gaskets,pistons,rings and everything for 900+ dollars. Is that too much to put into a 30yo motor? Or should I just say it will be a 2011 1981 motor that will last another 30years

Thanks for the info guys

 

[hidef]

Re: What got in the cylinder

If you rebuild it then engine should last a another 20 or 30 years. You will spend at least that much on another used motor without knowing it condition and easily 8 times or more that amount on a new engine. If the lower unit is solid and the outboard hasn't been run in salt then I would rebuild it.

 

[archcycle]

Re: What got in the cylinder

Or should I just say it will be a 2011 1981 motor that will last another 30years

Thanks for the info guys

Sure that part of it will last you. Just remember a lot more goes wrong with outboards than cylinders and rings. There are plenty of things left to drive you crazy that are still 30 years old.

 

[levi_tsk]

Re: What got in the cylinder

no its not too much i dont know about you but the resale value on a freshly rebuilt cross flow here is in the 2500-3000 buck range

 

[emdsapmgr]

Re: What got in the cylinder

Is the crank re-useable or did it get damaged when the center bearing went?

 

[snagalager]

Re: What got in the cylinder

The crank looks good to me but I will have it checked.