Johnson 88 SPL one cyl low

[Bob1957]

Ok I'm taking my first plunge into the iboat pool here.<br />I am looking to purchase a very nice 88 that carries 110 PSI on three cylinders and very low PSI on the fourth. The owner (an outboard mechanic)is willing to part with it as-is for cheap and suggests that I hone the three good cylinders and bore the fourth. Two questions.<br />Is this a reasonable thing to do? I have always been of the belief that all the cylinders should be the same.<br />Second, I am an above average mechanic and have a knack for fixing anything although I have never tackled a multiple cylinder outboard. How difficult are the 88s to work on? i.e. special tools and advanced knowledge. I'm very good at following a manual.<br /><br />Thanks in advance,<br />Bob

 

[Mo.CrappieFisherman]

Re: Johnson 88 SPL one cyl low

If you bore it out then it will have a higher compression then it does know. You might check to see if this will effect your motor or not. JoeReeves is good you might ask him he has helped me out a lot on here.

 

[R.Johnson]

Re: Johnson 88 SPL one cyl low

You can bore out that one cylinder, depending on how badly it is damaged. How much does the man want for this engine. On a engine of this age with a damaged cylinder, if it does not have tilt, and trim, I would offer maybe $100, I have bought better for less.

 

[Bob1957]

Re: Johnson 88 SPL one cyl low

The motor has tilt and trim, I already decided that $200 would be max.

 

[OBJ]

Re: Johnson 88 SPL one cyl low

Might want to take a peek at the bad hole Bob. Make sure it's salvagable. You can bore the holes out .030 to .040 over depending on how bad the hole is.<br /><br />The TNT is a plus and the block is a proven block that's been around for a long time.<br /><br />I think the point here is to make sure you know exactly what you are getting. Wouldn't hurt to take a look at the gear lube also...give you some idea of what condition the lower unit is in.

 

[itstippy]

Re: Johnson 88 SPL one cyl low

Welcome to the iBoats boards!<br />There are a dozen experienced pro's on this board who rebuild the OMC (BRP) outboards routinely. I am not one of them, but I read what they write. It is common practice on a three-cylinder to hone & re-ring two cylinders and bore & oversize the third. The replacement oversize piston is the same weight as the originals, so everything stays in harmonious balance.<br />Two-stroke outboards use a different formula to determine the final bore for oversize; 4-stroke shops often mess up and don't get it right on the 2-strokes. Too tight and then stuck rings. If you take on this project make sure you hear from the pro's here on what piston to use and what final bore should be. These guys are really good and generous with free advice.<br />Post the model #. These guys visualize stuff in their heads and always want to know the model #.

 

[rodbolt]

Re: Johnson 88 SPL one cyl low

best couse of action is to decide to tear it down for inspection. usually after a careful inspection you will find that after honeing the cyl specs for taper and egg are still out and the spec for max piston to wall is borderline. if nessasary that motor can be sleeved so usually sleeve damage is not critical..<br /> if no water has entered the crancase and the rods and crank are reusable its a simple motor to recondition. but plan nothing until a teardown is complete. I always teardown the gearcase as well. seems most outboards while dying folks tend to jack up the idle speed and slam shift them. most failures are due to neglect and the neglect usually includes the lower unit as well. its a bummer to get the powerhead squared away only to have to pull the gearcase after the maiden voyage.<br /> some of the procedures that require special tools can be done at a local dealer. <br /> if this is a salt water motor make allowances for broken fasteners as well.<br /> trust me on this if nothing else. as far as the mechanical subsystem goes the fit and sealing of the piston/ring assy is absoluty critical to decent idle and longevity. does not matter if you use new rings and the skirts are collapsed and the bore is borderline, you will now have a worn out reconditiond motor. so a careful inspection both before and after any block operations is mandatory.

 

[Bob1957]

Re: Johnson 88 SPL one cyl low

Thanks everyone, I have already gained great knowledge in the last 24 hours. Unfortunately the owner of this motor feels that it is worth more than I paid for my boat and trailer, thats a whole other story. Even though the motor is in excellent condition other than the bad cylinder, I can't help but wonder why that cylinder failed. Guess I'll never know. I'm still looking for a motor though and beginning the process of bringing a 1976 Cobia bowrider back to life, so rest assured you will be hearing from me again.<br />Thanks again for all the help,<br />Bob