User Tag List
Thanks: 0
Results 1 to 15 of 18
-
09-27-2014, 03:17 PM #1
300xs cylinder endoscope inspection
I inspected my "good" 300xs with 13.4 hours on it after my other twin 300xs lost #5 piston and rod went thru the block. Does the spot in at the edge of the piston look like a chip in the piston? Note that due to the wide angle of the scope, the piston does not look round - it is the gray portion of the photos and the cylinder hatching is pronounced.
-
09-28-2014, 09:49 AM #25000 RPM
- Join Date
- Mar 2006
- Location
- Oklahoma City Ok.
- Posts
- 145
- Thanks (Given)
- 0
- Thanks (Received)
- 6
- Likes (Given)
- 2
- Likes (Received)
- 11
- Mentioned
- 0 Post(s)
- Tagged
- 0 Thread(s)
Not operating the borescope its hard for ME to really see what we are looking at BUT those pics look like cylinder bore (hatch) then headgasket if they use one. But in either case I see little hotspots with some piston splatter or something that is balling up in photo one. My 300xs only has about the same number of hours and hope I don't have the same luck. What did Mercury say about the one that blew, and what year of manufacture was it? Mine is 2013 sold in 2014. Roger
-
09-28-2014, 11:22 AM #3
Roger, What is posted is cylinder bore (hatch) then gap (which I think is the ring below the top of the piston) then piston (the gray splotched piece). Because of the extreme wide angle of the lense, it looks like the piston is curved the reverse direction that it is (round). So the "spot" at the edge is on the edge of the piston which looks like a piece is missing. Mercury doesn't let the servicing dealer open the motor. My tech thinks that " a small piece of aluminum" probably made a hot spot which either cause pre-ignition of detonation which lead to lunching the motor. My concern is that the "spot" is the genesis of a hot spot and then it's over! My motors are 2013's. Not also that Mercury has revised their break-in procedure for the replacement powerhead.
-
09-28-2014, 12:02 PM #4
What is the revision to the break in procedure?
-
09-28-2014, 12:39 PM #5
I checked the "new" furnished schedule with my Operations Manual schedule that came with my motors... No difference!
-
01-08-2017, 07:22 PM #6
Any update on this?
Checkmate 2002 Convincor 270 496 MAG-HO
2003 Cougar 22MTR w/300xs SOLD
90 21Skater w/300xs - sold
98 STV Euroski w/280 - sold
2006 Trailblazer SS 6.0l 395hp
-
01-10-2017, 11:43 AM #7
I have about 30 hours on the motors. Both are now working well. I had to replace all the coils on the replacement powerhead due to a dead cylinder (port motor). They were reused from the broken powerhead. Mercury provided the new coils! I am still chasing being down 250 RPM's on the starboard motor. Maybe an intermittent coil issue there as well. only getting 6000 RPM on the starboard motor. I took this photo on December 27 - pretty good run!
-
01-10-2017, 05:00 PM #8
Attachment 364407 "I'd say'
Wriggleys gum makes me think of boating, "Double your engines, Double your fun"
-
01-11-2017, 08:36 AM #9
-
01-11-2017, 09:16 AM #10
Thanks, After more research, I totally agree with your description of what is in the photos.
-
01-11-2017, 09:46 AM #11
-
NICE PAIR liked this post
-
01-19-2017, 12:19 AM #12
-
01-19-2017, 07:20 PM #13
I don't see the piston in any of the pics. What it looks like to me is that you see the cylinder crosshatch. The lighter color is where the ring rides. The darker color is the cylinder wall above where the ring stoops at TDC. Next is the cast head. These motors don't have a gasket they use an oring. The area that looks goldish like a head gasket I believe is the machined squish are on the head that over hangs in the cylinder. I believe it's pretty fair to say that's not a chip in the edge of the sleeve as you can see that in one pic it looks like you can see one side of the "object" and another pic the other side. I'm very curious to see if is a piece of aluminum or a chunk of carbon. I highly doubt it and hope it's not part of the oring that came out of the groove during assembly and got crushed while torqueing the heads and now has become charred....
Curiosity would definitely get the better of me and I'd be tearing that head off to see !!!!! It's only a total of 4 orings to replace.....
-
01-19-2017, 08:24 PM #14
-
01-19-2017, 09:27 PM #15
I removed my(2007 300xs) injectors and air injectors and sent out for cleaning due to what felt like a "vapor lock" for about 30 seconds on warm/hot restart. Going to start a new posting with cylinder pictures from Snap-On bore scope. Will try to get up over the weekend.
Checkmate 2002 Convincor 270 496 MAG-HO
2003 Cougar 22MTR w/300xs SOLD
90 21Skater w/300xs - sold
98 STV Euroski w/280 - sold
2006 Trailblazer SS 6.0l 395hp