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I would imagine that the type of nail has a decent impact on how one might solve it....

you are correct.

The guy I bought it from kind screwed me, he didn't tell me any oif the problems this bike had.

that's never happened before . . . 

a seal is either super hard or super easy to replace.  if you're lucky it presses in from the outside of the engine (i'd bet yours does).  if you're not lucky, it presses in from the INSIDE of the engine, which means you'll have to split the case (so help me lord i hope i never have to do that).  if you do remove that seal, be sure to check the shaft that went through it - sometimes they can get a wear mark from rubbing against the seal and that is what is actually causing the leak.  usually you can just sand/polish the shaft smooth again.

gross-ree

Well, I wont be able to get to it for a while.  I know for a fact we didnt do all that when we tested the compression.  I dont remember opening up the carb to allow more air, or screwing with the mix or anything like that.  My buddy just took the spark plug out, stuck in the gauge which wasnt like your normal comp tester, with the single dial.  This one was sort of this weird contraption that looked like a couple thermometers set next to each other, and the compression would read out like a thermometer does.  Although I think it was using air to set the gauge to whatever.  Man, Im having such a hard time explaining this stupid tool.  Anyway, yeah, we DID notice the compression difference was at the limit, or whatever, 30 lbs of difference.  So, as soon as the sun comes out and it stops raining over here Im probably going to give it a shot.

what you're describing sounds like a vacuum gauge used to synch the carburetors, but if he plugged it into the spark plug hole, then, uhh, i guess you where checking compression.

oh, and just to be clear- when i said you should check compression with throttle fully open - i didn't mean to adjust anything on the carb, i just meant to twist the right hand grip to wide open throttle.  this opens the butterfly's in the carbs all the way and lets as much air in as possible.  (also let's air leak back out in the case of a bad intake valve - so you don't get a falsely high reading)

another trick i've heard to check for symptoms of bad compression is to make up a fitting so you can put compressed air into the spark plug hole and see if you can use your air compressor to turn the engine over.  if you got bad exhaust valves, you'll hear it leaking out the exhaust pipe.  if you catch my drift.

I also have another question for you, though.  One of the first things I did was replace the stator when I got this bike.  This entailed dropping the engine since the stator is IN the block (shitty), but since the engine weighs less than 100lbs, I think, it was pretty frickin easy.  Now Im having 2 problems, one is I have a coolant leak(Im thinking the gasket to the water pump got pinched when I was putting it back together and now its leaking from there), and this compression thing.  Oh, and I need to change the gasket on the fan blade(this bike has a radiator, which I dont think is that common for bikes), and the thing is leaking oil like crazy. Im planning on dropping the engine again, and replacing the front gasket(its the gasket that goes around the camshaft I think, where it connects to the fan blades on the front of the engine, although it could just as well be the crankshaft, not sure, since I dont have cams I guess??).  Anyway, does that sound like the right move to you?

i take it this is your bike, then?


it looks like the cover right below the radiator is what you need to pull off to manually crank the engine over and check the valves.  although,  if that's not where your stator was, then you might have to drain the oil before you pull this cover off.  like i said - i've never worked on v-twins before.  i strongly recommend you pick up a manual.

with that said:

coolant leak:  i've heard a little black pepper in the coolant can plug leaks and is soft enough to not damage the water pump - try at your own risk.  i think there are also some additives that might be worth trying before you pull the engine again.

fan leak:  i apologize for misleading you about the cam-shaft.  you do have a cam shaft, but it's not an overhead cam shaft.  your camshaft is above the crank shaft and is driven by a chain.  (overhead cams are driven the same way except the chain is a lot longer and there's no push rods - the cam shaft acts directly on the rockers (unless you have bucket/shim valves in which case there are no rockers either and the camshaft acts directly on the valves).  i always assumed bikes with push rods were set up so the crank shaft did double duty as a cam shaft (i think this *might* still be the case with harley's). 

anyhow - i'm flat out guessing here, but i'd bet what's going on is that you have a bad seal.  the gasket around the cover that is leaking oil like crazy is probably not designed to hold oil in, but rather keep dirt out.  the seal around the camshaft is probably bad and is leaking into an area where there normally shouldn't be any oil and that is why it's leaking.  course, now we're getting into the "i've got an image in my head of what you're talking about and it might not be what you're actually talking about" territory.  i'd strongly recommend you get a manual.  if you're lucky you might be able to find a pdf online or something. 

i like the golf ball and tee inside a snow globe.  pretty simple puzzle - you just have to balance the golf ball on the tee, but it's kinda tricky to do.

i have a few tavern puzzles (like the two horseshoes and ring).  i recently re-solved one that i hadn't seen since i was a kid.  the only way i can describe it is that it's sort of inspired by bell and you have to get a ring off.

i had another puzzle when i was a kid call "spin out" that looked kinda hard, but turned out to be kinda mundane.

never could completely solve a rubik's cube.

here is a puzzle you can make yourself:

all you need is a block of wood and eleven nails.  roofing nails are too short.  finishing nails don't have enough of a "head" on them.

pound one of the nails into the block of wood just enough so that it stays put.  80% of the nail should still be sticking up.  the puzzle is to balance the 10 remaining nails on the head of the nail you just stuck in the block of wood.

this page illustrates the puzzle, but also gives away the solution, so don't look at it if you want to figure it out on your own. 

this ginormous tool chest comes with a built in fridge and stereo. 


also - this is what i really wanted for christmas:

i thought this was going to be about the kind of chain mail that, if you don't send copies to 10 people, bad things will happen.

i found a pic of the bike and it totally looks like the V65 Magna's.  i'll keep my fingers crossed that it's just tight valves for ya.

edit: oh yeah, it also looks like the cover you need to remove to turn the crank over is on the front of the engine. (longitudinal crankshaft)

[not]

oh - ok, pushrods = not overhead cam.  i thought harley had the market cornered on that design.

i'll apologize in advance if i come across as condescending, but i have an OCD-like desire to be understood clearly which causes me to over-explain which sometimes the person i'm talking to takes to mean i'm talking to them like they're an idiot.  (i.e. i've been known to explain how to solve a calculus problem by starting with "you know how to add, right?")

so to be certain you are doing a proper compression test: you need to have all spark plugs removed,  have the throttle wide open, and turn the engine over a few times until the gauge stops climbing.  you need to remove all spark plugs because the compression in the other cylinder(s) will cause the starter to have to work harder and not be able to turn the engine over fast enough.  you need to have the throttle all the way open to allow as much air as possible to flow through the carb and into the cylinder.

there are three possible causes for low compression:
    worn piston rings, bad head gasket, valves not sealing properly.

you can rule out worn piston rings by squirting some oil into the cylinder (through the spark plug hole) and repeating the compression test.  if the compression stays the same, then the rings are good.  if the compression reading goes up - that means the oil plugged up your leaky rings and you need new rings.  (i.e. pray that when you put some oil in there, that the compression doesn't go up).

if you're ruled out piston rings by using some oil.  you know it's either the head gasket or the valves.

the next step is to check your valve clearances.  your valve clearance is the distance between the top of the valve and the rocker arm.  the crank shaft has lobes on it that push up on the push rods, the other end of the push rods, then, pushes up on one side of the rocker arm causing the other side to go down.  (that's why they're called rockers, cuz they rock back and forth).  the other side of the rocker then pushes down on the top of the valve stem and opens the valve.  the valves are held shut by a spring.  when the rocker is not pushing down and holding the valve open (i.e. when the valve should be shut), there needs to be a gap between the valve stem and the rocker arm - if the gap is too big, the valves open later and shut sooner. if the gap is too small the valves open sooner and shut later. 

the problem is that your engine is made out of aluminum and is softer than the material that the valves are made out of.  while the engine is running your valves repeatedly slamming shut and beating themselves deeper into the head of the engine.  this means that as the engine runs, the valve clearances shrink.  eventually, the gap can shrink to nothing and the valves will never completely shut.

a lot of people notice a "sewing machine" ticking noise coming from their engine and think there is something wrong - but the ticking is actually the rockers making and breaking contact with the valve stem.  the time to worry is when the ticking goes away.

if you can rebuild a carburetor, then you can check your valve clearances and you don't need to pull the head(s) off to do it.  you will need a set of feeler gauges and you will also need a manual to tell you what the clearances should be.  pull your valve cover(s) off and have a look.  there should be a cover on one side of your engine (usually the left side, but i'm not familiar with this engine . . .) that you can remove to expose a large nut that is connected to the end of your crank shaft - you shouldn't need to drain the oil.  you use this nut to turn the engine over.  under this cover, there should also be a wheel with marks that show you top dead center.  as you turn the engine over you can watch the rockers go up and down and push the valves open and closed.  again, a hayne's or clymer's manual will walk you through the process.

use the feeler gauge to check the clearances, with any luck, you'll find some valves that are too tight.  to adjust you simply loosen the lock nut and turn the screw (aka "tappet") on the rocker arm until you have the correct clearance and tighten the locknut back down. 

if you do find that your valve clearances are all in spec then, unfortunately, pulling the head is required.  which means you're gonna replace the head gasket whether it was bad or not.  the valves may just need to be cleaned, or it wouldn't hurt to take the head and valves to a machine shop and have them done.  looking at that engine on wikipedia, it doesn't look like you'll have to remove the engine to do it (bonus).

course, your running sluggish issues could be carb related and have nothing to do with the compression.

hiding the pickle is its own prize.

is it a gherkin?

think of it as extra training?

i don't mind the snow until about mid may, then i get kind of tired of it.

ah, shit - i just remembered, it's a CM400 (not a 500) and it's a parallel twin, chain drive.  it's the great grandfather to the honda rebel, really.

i have no experience with v-twin engines (single cylinder, parallel twins and straight 4's for me).  you say v-twin but left and right?  v-twin like the old magnas, i take it? 

put a few drops of oil in the cylinder (via the spark plug hole) with the low compression (spraying WD-40 will work even)  and check the compression - if it improves, you need new rings (the oil improved the seal).  it if doesn't improve, then it's valves or head gasket.

if you're lucky, you just need to adjust your valve clearance (too tight means the valve isn't closing all the way and not holding compression)

30 psi difference between cylinders is about the max acceptable difference. 

if you can, do a plug chop and see if you're running lean (white spark plug).  if you are, then it would indicate a possibly burnt valve.

however, running good cold and losing performance as the engine warms up is typical of running too rich.  also, a hot engine should more compression than a cold engine.

how many miles are on it?  does it have a single or dual overhead cam?  is it a single carburetor, or does each cylinder have it's own?

outside the box is the new inside the box?

very cool.  you've done a great job cleaning up that bike.  good luck with those side covers.  i was extremely lucky to find strong online support at xjbikes.com for my yamaha seca. 

i'm trying to fix up my buddy's '81 honda CM500C.  i fear i will be pulling the head off pretty soon, as teh compression is not very good and with now immaculate carbs and properly adjusted valve clearances, it still doesn't run very good.  you wouldn't know a good resource to get used parts for early '80s Hondas online, would you?  i need a new (cheap!) front master cylinder for that bike, too.  i might have a few miscellaneous parts (mostly lights and turn signal related) that might fit your '82 CX500.  Let me know if you need anything and i'll check it out for ya.

too bad you're so far away. 

i love working on bikes, but i absolutely hate working on cars.  i recently had to replace the heater fan in my truck and it completely sucked.

safety tip:  something i recently learned about old drum brakes - the brake pads can, over time, delaminate from the shoe.  this can cause the wheel to suddenly lock up (even when you're doing 70mph).  take the time to check out all your drum brake pads (if you haven't already).