What could possibly lead to this. Is it just way to rich or maybe blowing past my rings? it looks like I am getting combustion under my piston as well as on top (yay i've invented a 1-stroke)
Well this certainly doesn't look good
- Thread starter ruthless_one3k
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no wonder ported motors are so fast =))
j/k I don't have a clue what that could be... I've never heard or seen such a thing. crazy
j/k I don't have a clue what that could be... I've never heard or seen such a thing. crazy
I'm guessing that this has something to do with me only having 102psi of compression. weather this caused the low compression or the low compression caused this idk. Anybody else seen this?
just my opinion but i would say it is rich and or some bad/dirty burning oil...i think the residue on the bottom of the piston is just from premix oil carbonizing and getting too hot and sticking cause its only on the bottom of the dome and the thicker piece where it would be hottest(no combustion going on down there...you def would have noticed lol)...and on top of the dome is just some nasty carbon build up it looks like.
The oil is klotz supertechniplate 80% synthetic 20% racing castor I cant remember for sure but I think it 32:1 or 40:1. I ran it a little richer than that during break-in maybe this is why I have so much carbon build up.
Would this lead to low compresion though?
Would this lead to low compresion though?
well if you run alot of oil when breaking in you may think you are doing your motor a favor but your not. I have always heard if you provide too much lubrication the rings wont seat correctly...the whole point of the break in is to have the rough surface of a hone job wear and match your rings to the wall perfectly. So that might have contributed to lower compression. As far as oil i would say running alot of oil during break in when you probably werent riding it that hard was the main cause of all the carbon...and i also believe that castor, while making more power when burnt, burns slightly dirtier. how many hours are on this top end?
wow haha...well then you definitely didnt get those rings to seat good, also idk if you took into account that by adding extra oil into your premix you effectively leaned your mixture out, so you were probably running a little lean+hot which would explain the varnishing on the bottom of the piston...the good news is that because you only have 8 hrs on it your bore is fine, you can just get a set of new rings which are pretty cheap and hone it and you will be good to go again. Your compression will go way up if you break it in right, remember use regular amount of oil, or maybe even a little less! you have to wear the rings and wall during break in for good seal and compression!
Thanks, but you bring up another question. You say adding oil makes it lean, I've always thought it would make it rich. but I have heard others say the same thing about it leaning it out. could you explain a little please?
yeah its not real complicated, your carb is going to inject a given amount of "liquid" no matter what it is...it does not know how much oil you have in the gas....so say you mix your gas at 40:1...thats 40 parts gas for 1 part oil...so in this case your a injecting 97.5% gasoline, 2.5% oil ...but if you mix at something like 32:1 your injecting 97% gasonline, 3%oil....small differences i know....but say durring break in you throw like 20:1 in there with alot of oil....thats only 95% gas....so effectively 2.5% less gas than 40:1....that is quite a bit of a difference when you are talking about tuning an engine...you cant just change how much fuel the engine is getting by that much and expect the jetting to not be off
^ said another way... if you add more oil, its like jetting down because its burning less gas, in exchange, leaner.
theres a rich and a lean oil wise and fuel/air mixture wise.
theres a rich and a lean oil wise and fuel/air mixture wise.
After thinking about it I get what your saying. I never really thought about it before or I would have realized that the oil does not burn till after combustion and in the pipe. I think I'm on the right track now. thanks a lot
no idea. id say sanding, but i bet the engine builders here would say bad idea. it just sticks to it like its part of it. i tried with an old piston, didnt even get it off, got like a bit of the surface sh*t.
^ good idea. reminds me of the one at my local shop. i did the co-op there so ive used it a couple times. one machine that scares me lol. idk what they did, but it spins up SO DAMN FAST. like sure they get goin pretty quick, but this thing, so fast it seems like all the wires are going to spray out. anybody that uses it is like wtf. its jokes.
Well I couldn't find my CLR so its soaking in a very unhealthy mixture of cleaners I found under the bathroom sink. If that don't work then the wire wheel it is!
