1987 evenrude 88 spl rebuild

[bay rat]

i have an 88 evenrude spl that lost a lot of power and i have to choke to start.i checked the compresion 120 psi in three cyl fourth has 90 psi i took the heads off the cyl with the low comp looks beat up and chiped .my question is can i just change one piston? do i have to remove the block or can i just take the piston out and how? if it was caused from the thermastat can i use it with no thermastats?

 

[bay rat]

Re: 1987 evenrude 88 spl rebuild

please send photos to gebdud@aol.com 88 spl rebuild thanks

 

[Dhadley]

Re: 1987 evenrude 88 spl rebuild

Yes, you can change just one piston as long as the cylinders all measure in spec. Its doubtful they will. Once you get it apart a machine shop can measure it for you with a dial bore gauge.<br /><br />Its not likely the thermostat caused the problem. Was it a starboard piston thats damaged?

 

[bay rat]

Re: 1987 evenrude 88 spl rebuild

yes its the starboard side lower piston.

 

[Chinewalker]

Re: 1987 evenrude 88 spl rebuild

Get yourself an OEM shop manual. You'll need to completely tear down the motor - no shortcuts! While you've got it apart you'll probably be better off by at least honing and re-ringing any bores that are still in spec. Refurbishing one cylinder and not the others is a recipe for having it happen again... Gotta keep the thermostats in there - can't run the motor (for long) without them.<br /><br />Also - find the source of the problem - Lean condition in carb? Bad thermostat? Air leak? Whatever it is - fix it or it'll blow again.<br /><br />Be prepared to break stuff as your locale means it was probably run in salt... You might get lucky, but chances are you'll at least snap a bolt or two...<br /><br />- Scott

 

[Dhadley]

Re: 1987 evenrude 88 spl rebuild

I'll bet it was being lugged. Top rpm in the low 5000 range. Close?

 

[walleyehed]

Re: 1987 evenrude 88 spl rebuild

Quote from my prop test data; <br />

RPM BELOW NEAR 5200 SHOWED HIGHER THAN NORMAL CYLINDER HEAD TEMPS AND HIGH FUEL CONSUMPTION <br />

Dhadley hit it close......I'll bet.

 

[Toontime]

Re: 1987 evenrude 88 spl rebuild

I don't mean to hijack the thread, but I'm curious. I own a 94 Rude 88spl on an 18 ft Alumacraft mod v basser, aluminum, riveted. I have only managed to get low 5000's from the engine as propped (17in). Trimming creates porpoising problems. 97 model boat. My compression figures are higher than rat's but show the same pattern. Why does the lower starboard piston show less compression and why do you guys recommend 6000 rpm when the book calls for 4500 to 5500? Why is 5000 lugging?

 

[walleyehed]

Re: 1987 evenrude 88 spl rebuild

Your 94 is a crossflow, and yes the book says 4500-5500.....in 1994 on 1994 quality fuel.<br />we don't HAVE 1994 quality anymore, fuel-wise.<br />It's a fact that with todays fuel those engines develope less coking and lower combustion temps if set-up for 5800 on the crossflow and around 6000 on the looper. The over-all results through-out the power band will be advantageous as well.<br />The engine will handle these RPM's just fine, don't worry about that.