Spark plugs

[NewNitro]

On my 1986 Black Max 200 A914326, I changed plugs after having a sudden loss of power. Hoping it was the plugs with a years run time on them. The new plugs were run a mile up river and back down. Realized plugs weren’t the problem and didn’t want to run it too long. The old plugs didn’t look any different than the new, other than this one, center of port side. What’s this telling all the experts? DAF9E2B8-F447-493B-A6C3-F1F40E8759E5.jpeg

[JOE54]

you check compression on that cyl sure looks like ALUM specs to me /pisston

[NewNitro]

677DE221-5FB8-402B-9FB0-B53363B692CB.jpegSame cylinder with a new plug and 3 mikes or so of runntime. All the old plugs were this clean

[NewNitro]

Here’s the problem Well thought I’d post a picture but it says my file is too big ? So I screen shot that announcement and it’s too big to download even though it’s smaller than the maximum they say it will take. Just the kind of day I’m having. Lol. Oh well thanks for your help, now to find someone to rebuild or a nice used one.

[JOE54]

describe it please

[NewNitro]

Best description wouid be pitting in a crescent shape on the lower right quadrant of bottom cylinder on port side. Oddly enough the cylinder with the dark spark plug was ok.


So i've resized the picture down to 600x825 and it says it's too big tho it says the mqax is 1025x 768? i'm confused

[NewNitro]

7D3B4C32-4CE3-4705-B5FA-FD4BBBA948A9.jpegThat’s a thumbnail size of it

[JOE54]

so has dark plug ever been in cyl with piston damage

[NewNitro]

so has dark plug ever been in cyl with piston damage

No, it was in the cylinder above it

[JOE54]

any erosion on that piston dome in same location as lower one

[SilverFox579]

No reason I can think of you can't upload a bigger pic, using the "insert image" button here's one that's 3648x2764 and 1.6mb, automatically thumbnailed by forum software. Guys here routinely post 7mb pics, which is way overkill IMHO. I normally resize mine to 1024x768 and <500kb which is plenty adequate, IMHO, for diagnostic purposes.

003.JPG

[EuropeanAM]

See if you can get a full-picture view of the crown of that piston (as well as the exhaust port, if possible).

[NewNitro]

Ironically I can’t post the message I get when it says my photo is too large. Lol can I sent photos to someone via text and see if they can down load? I just snugged the head back on it and can take all the photos you want. I can’t find a motor to repower or anyone near to rebuild it, so I’m going to go ahead and start taking it apart to educate myself on how these work. Never too old to learn. The carbs were starting to leak etc. I can send pictures as I go. It is calling for heat index of 100+ here today so not going to do too much lol

[JOE54]

likely gonna need some sleeve work done , haa been that temp here for a while , temps over 90 inside my insulated shop

[NewNitro]

IMG_0045.JPGI'd say you're right. This is starboard side, bottom cylinder, not even sure what i'm looking at. At 10 o'clock on the cylinder wall, that feels like rubber? It actually flexes.

[NewNitro]

I'm a frequent visitor on other forums and this one occasionally, not sure what y'all like to see as far as too few or too many photos. I took photos of each cylinder and each head (both are bad). 30 or so photo's all together.I thought i was going to rebuild but now not so sure, i'm finished for the year any way i go. Can't find a motor anywhere to repower with and not sure where to turn now.

[NewNitro]

No reason I can think of you can't upload a bigger pic, using the "insert image" button here's one that's 3648x2764 and 1.6mb, automatically thumbnailed by forum software. Guys here routinely post 7mb pics, which is way overkill IMHO. I normally resize mine to 1024x768 and <500kb which is plenty adequate, IMHO, for diagnostic purposes.

003.JPG

Was trying to do it from my phone, apparently that was the problem ,hooked up an old desktop and i seem to be able to download now, thanks

[NewNitro]

IMG_0016.JPGIMG_0042.JPGIMG_0015.JPGBottom port side piston in first photo, center photo showing spark plugs with one years use left to right are port side top to bottom and then the head from port side.

[SilverFox579]

delete

[SilverFox579]

Was going to post piston pic you emailed to me but see you got pic posting figured out!

You're going to need more than sleeve work, piston, rings, probably more. I'd weigh rebuild cost against replacing with a well cared for and fully checked out Optimax.