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Thoughts on how this runs?

I just picked up this little Evinrude. I know very little about 2-stroke outboards and how they should run. Most of my experience as a mechanic is with big trucks. This one has no serial plate on it, someone in the identification section of the forum said it's a 6 to 8HP. No clue on the year, although the carb has a little white nylon looking piece that surrounds the main jet, it has a tube that looks like it goes up to the idle jet, looking through parts diagrams some years did and some years didn't have those. It wouldn't idle, I cleaned out the carb and adjusted the idle mixture screw, seems to be doing OK now. Idle speed seems low to me, if I crank the throttle all the way down it seems to dip down to 700ish rpm sometimes and will eventually stall. Should I bump it up a bit?

How about the knocking/shake when decelerating while in neutral, is this normal for a 2-stroke?

Tuning thoughts would be appreciated. Excited to get it out on the water soon and see how it really runs.

 
Get that thing on a boat on the lake, where it was designed to run. The sneezing is to be expected with the way you are treating it.
 
The service manual for 91-95 says,
“Start the engine and allow it to reach normal operating temperature. Shift the motor into forward gear. Rapidly advance throttle to wide open position. If the engine stalls or backfires, the idle mixture is too lean. Turn the low-speed needle Va of a turn counterclockwise. If necessary, repeat this procedure.”
Note- this is on the water & in gear, NOT idle.
I don’t know what boat you have it on, but on my 14’ Tracker Jon boat the 8hp will push it at 30k/hr (18mph), GPS.
The 6hp was slightly slower. This was with myself (175lb), my wife (120lb), fuel tank & a few lbs of fishing gear. The Jon boats plane easier than a V hull. If I have 3 adults it will just get in plane, at only about 10mph, if I were running 3 people or equivalent in gear, I’d mount the 9.9 I have.
Immworking on that service manual, it’s too big to simply email, I’ll have to upload it to iCloud, & send you a link.
 
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I got it out on the lake today on my little SeaBright inflatable. It pushes me at around 15-16MPH once it gets up on plane. It seemed to struggle a bit to get the boat up on plane, but maybe I'm just asking too much of it, I still have no clue of its a 6 or 8HP.

I put new NGK L86C plugs in it and gapped them at .03, fresh fuel mix, ran it for about 1.5 to 2 hours today. I can pull the plugs and take a picture of them if that is useful to some of you with way more 2-stroke knowledge than I have. Not sure if it would have enough run time on the plugs for that to be useful.

Here's a video of it running, would appreciate thoughts and feedback. I'm happy with it, but would love to know if its running at it's full potential or not.

Need to fix latch on the cover, won't hold it shut.

 
From doing some reading it sounds like that "miss" I am hearing may be the motor "4-stroking" where it's not hitting every other stroke like it should. As I understand it usually this indicates the motor is running rich, correct? So, there's no high speed adjustment on the carb so that rules that out. I've had the carb apart and disassembled and it is very clean. Perhaps something could be wrong with the synchronization between the timing advance and the throttle position? Maybe I need to get a timing light on it, and I guess I should check the compression too. An issue with the reed valves wouldn't cause this, right?

It seems to run good at idle and wide open, it's at some positions in between it seems to struggle a bit as can be seen in the video.
 
If you’re e still uncertain which motor you actually have, look at the little silver disc that’s embedded in the side of the engine block. It might be stamped with the model #
My 1992 6hp shows the model #, (J6RENM), as seen here. (Sorry, can’t turn it upright).
 

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Your 2.7 meter boat is 106 inches or 8'10"

A 10 foot boat should easily hit 40 KMH with a 15 hp

If I have to be honest it sounds terrible your first video.
 
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