Here's a first for me. Customer brings in his bass boat for repair.

Says it's not running right, sluggish to get on plane and barely turns 4000 RPM,s when it finally does spool up.

He also says he's had it to three other "mechanics" who have sold him tune-ups etc trying to get it running right.

I fire it up on the hose and it idles but idles high and just doesn't sound right to my tuned ear.

Looking over the throttle/timing linkage on the motor I notice the idle timing adjustment screw was cranked all the way up.

Timing light confirms timing is at 11 deg. BTDC. It's supposed to be 0 deg +/- 2.

I set timing and throttle linkage (sync and link) to factory specs but now it runs worse and won't stay running unless I

give it throttle. This is a 1998 Merc 200hp EFI so no carbs etc to be out of adjustment. Fuel pressure? Within spec.

I check spark. Good on all 6. Compression 120 psi per hole, check.

HMMM, wonder if the ECM is OK? Break out our never used, archaic EFI ECM tester. All good. HMMMM.

Can't unplug injectors with engine running to see which cylinder(s) are failing because they are buried in the intake "box".

Remove intake box and find a piece of reed petal in the intake. HA! There's the culprit! But that's not all!
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After removing the reed plate and cages and examining the inside of the cylinder block I noticed one of the cylinder liners

didn't look quite right. It happened to be the same cyl with the broken reeds, hmmmmm.

I removed that cylinder head and....
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It's supposed to look like this one..
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I've been wrenching on engines since I was in Jr High and have

never seen a 2-stroke cylinder liner rotate. Piston is damaged also due to the reed petal snacks.

How it didn't snag a ring and grenade I'll never know.

Moral of the story? Don't go to "shade-tree mechanics" who can't properly diagnose problems

or throw $$$ at a problem because Bubba on the internet said his Uncles buddies friend

had the same problem and changed out the turbo encabulator to fix it.

wow, those liners aren't keyed?   All my 2stroke experience was dirt bikes and lawn mowers, no fancy lined motors.  

And as far as missing the "slightly damaged" reed valves, that is inexcusable.....  

obviously the other guys just fucked with it to get it off the bench....  

good catch!  I feel bad for the owner, but it will be nice to have his motor at full power (finally)....  

What do reed valves do?

2-strokes operate differently than 4-strokes.

ETA - At 0.07 seconds into the vid, you can see the reeds depicted by the green

"flappers" at the lower left of the animation.

2-stroke crankcases are sealed and the air/fuel mix is drawn into the crankcase through the reeds.

The reeds prevent the mix from being pushed back out the carb/intake when the piston is on the down stroke.

It also allows the crankcase to build a little pressure called primary compression

that aids in driving the spent exhaust gasses from the cylinder and filling it with a fresh air/fuel charge.

I know I'm late to the party, but 'reed snacks' made me lol.

Crazy seeing a sleeve rotate...must have been a manufacturing defect?

I don't think it was a defect as that boat had been to our shop a few years ago

for an annual service. I looked at the records and it ran well then, so I suspect

the reeds disintegrated and caused that cylinder to run lean and hotter than normal. This

allows the aluminum casting to expand more than it's design limits and it lost

grip with the liner. It also hadn't had an impeller since it was in to us a few years ago.

This may have added to the cylinder overheating.

Good to see you in here again @eclark53520  !

I jump in here randomly and see who's dumping a bunch of cash into holes in the water!

I don't have much to say anymore since I sold my boat.

That's crazy!

Not a knock KB! But I wonder if you could have diagnosed the sleeve problem with one of these

with the angled mirror attachment through the spark plug hole?

I snagged one at Sam's on closeout for $29, great for checking cylinder wear if the compression is marginal on the little used kickers I tinker with.

Yes, one of the guys in my shop has one. The thing is that after finding the broken reeds, the intake needed to be dis-assembled to

find other broken reeds and petal pieces. That's when I noticed the "weird" looking liner. Removing the cylinder head on a 2-stroke

outboard is easy enough since there aren't any valves etc to deal with so I just removed the head.

This also allows a closer inspection inside the cylinder for small reed petal parts that may be missed by the camera.

In the end, the customer looked for over a month for a used replacement engine to no avail. I ended up selling him

a 90hp Mercury 2-stroke from our old rental fleet. Surprisingly, the little 90 pushed the boat just fine and the customer

was happy. That's what counts!

I know...I'm going to get another one some day.

I got laid off and since I as no longer commuting with my wife, I had to get rid of my truck because I couldn't(more like didn't want to) afford the gas for an almost hour commute each way.  Since I didn't have a way to tow the boat and no real options in sight, it didn't make much sense to own a boat that never got used.

I sold it to a real nice young guy that drove almost 3 hours to pick it up.  His first bass boat, and he was stoked to own a Ranger as his first.  Even if it was more than twice his age.  Last I knew, he was still fishing on it after he replaced the floor and some other mods/electronics updates.  He was thinking about a re-power, but wasn't sure because that old Johnson ran so well.

I enjoy your commitment to this forum, hopefully soon enough I'll have some more questions for ya!