motor questions

Energy One

outdoorsman26

Well-Known Member
so I started my FIRST ever v-twin tear down cuz my rear cyl blew out the base gasket, and when I pulled the cyl I noticed there was a small wear ring towards the bottom of the cyl and all the cross hatches were gone!! the guy I have doing the work (who has been doing it for 30+yrs) said he would like to see .010 taken out of the cyl!! so now I have to get new pistons, rings ect!! FUCK!!:down::bang::bang::bang: My question is WHY??:loony: I have always used Amsoil 20-50 and changed it every 3500mi, I run a K&P oil filter. the bike has 22k on it
 

woodbutcher

Mr. Old Fart member #145
Staff member
have you always run a good clean air filter. (i'm sure you have, just posing the questions)
 

TCALZ06

Well-Known Member
I had to redo my entire engine at 18k. My builder says he sees several S&S engines a year and says its normal for them.
 

Sven

Well-Known Member
Questions:

1. Have you taken a ring off [carefully], checked gap at both ends? If no taper, what's the problem? Rings need a crosshatch. Skirts are lubed by splash and need no crosshatch.

2. Was the bike smoking oil at idle?

3. Was the bike smoking down the road?

4. Was there a riding partner behind you that was sniffing that burning oil?

5. Was there no rider, a car came up the side of you and pointed to his windshield with the wipers on asking to guide him home, you left half a quart on his wipers.

If there is no to any of these questions, who you gonna listen to, turtle talk or someone sees normal wear and can't put two and two quarts together.

:zwhistle:
 

Little-Boo

Well-Known Member
Troop Supporter
It happens especially to those who like to rev their engines all the time just to make noise. When you do that it loads the cylinders up with fuel and all that excess fuel will wash down the cylinders which causes the quick cylinder wear.

You can put a band aid on it by having the cylinders honed and new cross hatch marks cut back in. Get the 10 over rings and file to fit. Make sure you have a ring cutter. The S&S manual tells you how to fit rings. That would last you about another round of 15 to 20k or more. I use 50 Wt Lucas oil to keep the bike cooler, but where I live it is always 95 degrees or better during the summer months. 20/50 is OK for highway riding only. In town and traffic it get hot . Bigger Pistons will put a load on the already worn rod and main bearing and could lead to other failures. If you go bigger replace the bearing in the rotating assembly and you will be OK. That is my 2 cent worth :D

Carlos :whoop:
 

pknowles

RETIRED
Looks like it's time for a new set of jugs and send them out for diamond cutting before the new build
 

cueball

Member
what motor? I just removed a set of .010 over pistons from my 107 and had to go bigger. Pistons are in great shape you would need new rings.
 

Sven

Well-Known Member
Again, key here is to see the score lines on the piston skirt vs. the score lines on the cylinder walls; goes something like this:

1. Filter Pleats = Micro means something like it takes the eye to see a micro 8 times larger, meaning, it takes a microscope to blow the debris up 8 times, so the human eye can see the score marks about to occur is called a micro size being enough to do damage like so.

2. Toothpick Standing = The only analogy that comes to mind is if you threw a box of tooth picks at the bike, every engine gulp cycle, meaning a toothpick finds its way past the filter pleats. Now the visual is to see the toothpick stand vertical in the cylinder. Now, that is the score line down the cylinder wall. It took that stone; lodged it between the cylinder and and piston; came down in the power stroke direction; is to make a line down that thrust side; the piston uncocks the rock as it moves the skirt in the opposite direction; dislodges the grit; the grit is hit by the splash; is "washed off"; drops down into the crankcase; the mist picks up the debris; scores the breather cylinder and case; as it moves to the bag or oil filter.

3. Compression Standing = Collect the lines around the cylinder that was made by the debris via the larger spaced filter pleat design vs OEM's. Those are now compression stealing lines you add them up to make one big air gap. There ain't no fuel washing down a proportion. The proportion is the demand out the jet hole vs. the intake demand. So in proportion, how are you going to wash down a cylinder and do what now? Lube is lube. Cold fuel or oil in the crosshatch, show me the seized engine due to a clogged air filter if we now talk fuel wash being on the rich side, there comes a stumble with it. There comes a drivability problem you won't ride a washing machine :roll:
 

Sven

Well-Known Member
A. So the question is... Do we see lines down the piston ring's contact face? That is compression loss. That is smoke entering the crankcase and out the breather = A sign.

B. A Sign (i.e., smoke signal) = The bike runs every cycle fire; there is poor compression and 'constant smoke' is now burn some oil down the walls the oil is sticking on. The comp/scraper rings can't push out the ring from the back, because the air is moving down the 'toothpick length' gouge; down the piston's score lines; down the larger air gap of the rings.

C. The Smoke Signal = Hindsight should have told you to check compression or leakdown before teardown. So, here is wash boy romping the fuel demand, lifts off the throttle and coasts some. Gets back on the gas and poof!; Smoke. There goes the tolerance/seals dry/smoke out the suck of the valve guide on lift. That sort of hangs in the muffler and then the second you move that pressure back out on the sustained, just a puff blows out and the rest you never see, because it is [burned] with every suck. What you saw was a lot of sucks going nowhere out the pipe. Then all of a sudden you see how much the bike is really a "total loss oil eater" you breakout of the tolerance windows of an engine;

1. Wear = Smoke.
2. Oil = Burning in the cylinder chamber says I was assembled wrong with rings upside down (don't ask); a memory failure [seals drying/cracking/shrinking]; score me a toothpick length of my coolooK'N; or am pleasantly worn out with tons of miles on it.
3. Smokingun&N = Compression loss due to toof decay you go picking the wrong pleat size.
 

Srodden

Well-Known Member
I read on here that inadequate engine warm ups can cause premature base gasket failures.
 

05chop

Well-Known Member
so I started my FIRST ever v-twin tear down cuz my rear cyl blew out the base gasket, and when I pulled the cyl I noticed there was a small wear ring towards the bottom of the cyl and all the cross hatches were gone!! the guy I have doing the work (who has been doing it for 30+yrs) said he would like to see .010 taken out of the cyl!! so now I have to get new pistons, rings ect!! FUCK!!:down::bang::bang::bang: My question is WHY??:loony: I have always used Amsoil 20-50 and changed it every 3500mi, I run a K&P oil filter. the bike has 22k on it
Do you have a picture of this( what you call a small wear ring) towards bottom of cyl?
 

woodbutcher

Mr. Old Fart member #145
Staff member
Throw the Amsoil as far as you can.
with a post count of 22 and a rep power of -0-, there should be alot of accompanying information to back up what your said, otherwise it just sounds like you are full of sh*t. sorry, but my opinion. :job:
 

Mr.D

Member
Once bit twice shy !
In the mid 80's. I worked at a shop supporting a lot of desert racers, Amsoil rep came around selling this new miracle oil. Offered me a case for free, along with a hat and a pile of stickers. I tried it and offered it to my customers,
2 weeks later my bike seized while leading my class in the Wells to Wendover National
Yes this was a long time ago but enough for me
True story!!
 

Mr.D

Member
Only 22 posts but I've been riding , racing , and making a living as a motorcycle mechanic since 1972.
Currently own a 06 Pittbull , 06 Ridgeback , and a 2012 Street Glide
Bought my glide in July and had over 10 k on it before the 45 day temp tag ran out
Not my first day!
 

RoadRider

Active Member
I don't use Amsoil but that is not the problem. I have been in the lubrication business for more years than I can count and in my opinion as long as you use a high quality motorcycle oil and change it every 3000 to 4000 miles it is six of one and a half dozen of the other. I think the air cleaner is a issue, running hard when the engine is cold and just abusing them in general is where most problems come from. I am also NOT a fan of using engine oil in the primary or the transmission . Engine oil is not made with the proper additives to efficiently lubricate gears or chains.
 
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