Midlake Crisis
Site Supporter
- Location
- Bakersfield, CA
Front has more buildup, back is cleaner, domes are very clean. Any thoughts?
Super Jet Read my pistons
- Thread starter Midlake Crisis
- Start date
I can read an "F" on the top and it looks like 0.25 on the right side and an arrow on the left......
did I win anything??
did I win anything??
Midlake Crisis
Site Supporter
- Location
- Bakersfield, CA
Fail. Next....
GIL
Power In The Hands Of Few
- Location
- Cullman AL
How long have they been in there?
Here is what Art tells me, who cares as long as it runs great and does not blow up. I assume you are trying to avoid the 'blowing up' side of things. lol
Here is what Art tells me, who cares as long as it runs great and does not blow up. I assume you are trying to avoid the 'blowing up' side of things. lol
Midlake Crisis
Site Supporter
- Location
- Bakersfield, CA
@Gil - one full season, a couple months ago I put a regular gasket on instead of the O-Rings as a temp fix.
I pulled the head to put the O-rings back in to bump the compression back up (runs @150 w/gasket, was @175 w/O-rings), and was just concerned that they weren't even and that the back was so clean. I was thinking it might be from water intrusion. The bore looks perfect though.
I pulled the head to put the O-rings back in to bump the compression back up (runs @150 w/gasket, was @175 w/O-rings), and was just concerned that they weren't even and that the back was so clean. I was thinking it might be from water intrusion. The bore looks perfect though.
GIL
Power In The Hands Of Few
- Location
- Cullman AL
IF (big IF) I understand things the way I think I do, the fastest way to remove carbon build up from a piston is a drop of cool water on top of a hot piston WHILE it's running. Obviously we do NOT want to do this. LOL
IF it were me (and it's NOT), I would put it back together with the O-rings and run it for 4-5 full tanks of gas, pull the head, and look again to see whats up at that time. I can't see any signs of DETO and you say the bores look good, run it.
I would HOPE that the headgasket on a o-ring style head was allowing a drop or 2 on the rear piston and that being the reason for no carbon.
Now for theory #382948792379 of the day, Crammit's 6mil pistons never carbon up-he runs MS109 mixed 32:1 w/Benol, HOWEVER-I run MS109 mixed 32:1 with Benol and my compression #'s climb over the course of a season because I have tons of carbon build up on my pistons. LOL
I am certain you are more confused now than before you started this thread. Honestly not my intention. lol
GIL
Power In The Hands Of Few
- Location
- Cullman AL
What do the plugs look like-frt vs rear?
Midlake Crisis
Site Supporter
- Location
- Bakersfield, CA
They have been running even and light to med toasty brown.
KTM434
Jamie FN Hickey
- Location
- Palm Coast FL
Even though those pics look like nothing to worry about... carbon buildup happens with a more lean mixture and a clean piston is a sign of running rich or water intrusion. I dont know what engine or carbs you have but FYI oem 44mm carbs on a 760 engine come with the rear carb jetted more rich than the front to prevent burning up the rear piston due to detonation. (on those bigger hulls with the bigger pump the crank flexes under a heavy load and thats why the timing is retarded on the rear cylinder, the rear carb is jetted rich, and the combustion chamber in the rear dome of the head is bigger to yeild a lower compression ratio... this is all done to compensate for the crank flex which advances the timing on the rear cylinder and could cause detonation/piston melt down)
Last edited:
Blue
Judging your cheapness
- Location
- St Cloud Florida
KTM 434 said it best there are a lot of variables depending on the motor setup. Basically its about right in the rear cyl and a little rich in the front. Check the carb adjustments to make sure front and rearcarbs are the same number of turns on the needles. If you can lean the front a little the throttle response may be crisper and make a little more power.
KTM434
Jamie FN Hickey
- Location
- Palm Coast FL
Do you mean lean the rear carb? The rear piston is the one with wash down...
Midlake Crisis
Site Supporter
- Location
- Bakersfield, CA
Thank you all for the input. For clarification this is a single carb all 61x setup.
- Location
- Boynton Beach
How about this:
before cleaning:
after:
before cleaning:
after:
Freakrider
X247
- Location
- Tampa Bay area
Last edited:
waterfreak
I had a vision!
- Location
- s florida
How about this:
before cleaning:
after:
that looks like a brand new stock 2011 SJ engine
- Location
- Boynton Beach
- Location
- Boynton Beach