1993 Evinrude 175 Ticking

[bow_vol]

Wondering how bad I’ve screwed up. Have a 1993 Evinrude 175 - got an intermittent beep alarm while idling away from ramp. Had never heard that before so turned engine off. Restarted multiple times with no alarm repeat so I proceeded on and boat responded normally and headed out, after short run engine appeared to go into SLOW mode, came off plane, ran rough at low rpms. Engine then died and would not restart. Started heading back on trolling motor for a while and tried motor again, started and idled rough allowing me to make it part way back but died again. Trolling motor again for an hour then big motor started again in SLOW , made it almost a mile before dying again. Made it back to ramp on trolling motor and headed home. Looked up alarm and appears it was VRO ‘no oil’. Also had some gas that appeared to be leaking around the VRO/fuel pump So I removed and then replaced with non-VRO pump, drained all gas and filled back up with premix. Started on the muffs and appeared normal. Back to lake today - started normal but was running a little rough and shaking as I idled from ramp. Very slow to get on plane but then evened out and appeared normal. Stopped at first spot, still a little rough at idle and low rpms but now noticed a slight ticking sound at idle that appeared to follow engine rpms. Next run boat got on plane normally and everything felt normal. When I came off plane I could still hear ticking noise. Only heard the VRO alarm the one time, never heard the ticking while in slow mode but now I am wondering if I have done damage based on the ticking noise. Any recommendations for do-it-yourself troubleshooting or ideas on the ticking?

 

[havoc_squad]

Compression Test cylinders, you're probably going to find your issue. Avoid the harbor freight testers, they have been notorious for wildly varying values.

Sounds like mild piston slap/tolerance issue, example: https://www.youtube.com/watch?v=iGg4CCiL1-I

If you see bad numbers, pull the heads on the bad cylinders.

Looks like parts ran dry of oiling and bad things started happening quickly.

Scoring on the walls and moving the piston up/down/left/right for play will tell you quickly the most relevant information.

If there was no scoring on the cylinder wall and no play up/down/left/right on moving the piston to the cylinder wall, you'd check for play in the connecting rod.

 

[bow_vol]

Checked compression today-

TEST 1
TOP L (94) TOP R (115)
MID L (99) MID R (115)
BOT L (102) BOT R (104)

TEST 2
TOP L (92) TOP R (112)
MID L (95) MID R (115)
BOT L (102) BOT R (105)

What is normal for this type motor? What is normal spread? Does anything jump out about this data that would suggest an issue?

 

[boobie]

No......!!

 

[bow_vol]

Pulled port side head to look at cylinder walls on two with lowest compression. This is port side top

 

[bow_vol]

This is port side mid

 

[bow_vol]

This is port bottom

 

[bow_vol]

Appears to be some scoring and aluminum on the walls of the top 2 port cylinders which are ones with lowest compression. Is this what piston slap would look like? Does it look like it’s bad enough to require re sleeve or maybe just clean up walls and new piston rings?

 

[havoc_squad]

As I mentioned above, for a normal cylinder in specification, one can take their fingers/hand and push up,down,left,right on the piston face and get very small to nearly no play/movement.

When there is significant wear/damage, the gap between the cylinder, piston, and piston rings gets a lot larger.

Video example: https://youtu.be/wkmbCDih4Lk

It's shown right at the beginning in the video.


I think the full diagnosis on those cylinders would probably be determined by looking at the piston skirts on the intake port. Not sure how difficult that is regarding the looper motors.

Significant scoring marks on the intake side and exhaust point to loss of lubrication. If the majority of the scoring is on the exhaust side, then that would point to the engine overheating at some point.

Two stroke lawn equipment example on reading piston damage: https://www.youtube.com/watch?v=b6BfSwtjTIQ

There may be subtle differences, but it should be close to the same on outboard two stroke motors.

 

[racerone]

Motor has to come apart now.----There are no band aids that will fix that.-------Just another example of 100 PSI readings in a bad cylinder.----Many folks think that 100 PSI is OK.----Here you see it can be misleading.-----A leak down test is a much better way to find this sort of damage.