Mikee Minute #8 - Crankcase Recirculation Systems

[Recycled Roadkill]

[quote="Oldboy"]I agree with you Roadkill. If anything, the inside of the filter will fill with the crankcase goo and eventually plug up. This may possibly start oil leaks elsewhere as crankcase pressure builds. Old cars had road pipes that hung below or near the oil pan height, usually cut on an angle to help drawn the fumes out, and as a kid, old cars always smelt like old lawnmowers...stinky. Does anybody notice this on a high mileage GL? Since I re-ringed my bike the air box stays much cleaner.[/quote]My '78 could be considered high mileage at about 115K but I've never noticed any odd smell.

[evilratwing]

I just noticed the other day that if I remove my oil filler cap with the engine running, a lot of air comes out... are my rings crap? Bike still runs really well.

[Oldboy]

All engines produce crankcase pressure, its a product of spinning parts and possibly blow by (compression going by the rings). The question is how much? The only accurate way to tell is with a leak down tester. It a tool that threads into the plug hole and with that cylinders piston at TDC and both valves closed, a pressure (air) is applied and this tool determines a percentage of leakage in that closed combustion area. The pressure can escape past the valves, rings, head gasket or crack.
A simpler method is a good old compression test. Most of these engines had about 165 to 175 lbs new.
This test doesn’t really tell you where its leaking out. But does give you an idea of how good your engine is.
I re-ring my engine because of oil consumption.... It help all the way around.
I'm sure if I ran my engine with the oil cap off too, there would definately be a noticeable pressure.

If your bike runs great, uses very little oil, has good power....don't touch it! enjoy.
Remember "If it ain't broke...don't fix it"

[fish]

If your bike runs great, uses very little oil, has good power....don't touch it! enjoy.
Remember "If it ain't broke...don't fix it"

[Sidecar Bob]

Hey Twinstar:
What do you think of this? http://cx500forum.com/index.php?/topic/ ... ntry134268

Do you think I would be better off to just connect the filter to the crankcase and plug the holes on the airbox?

[mikenixon]

'nother pix for you, and another example of crankcase/carburetor contamination. One of my current projects, black grunge on the slides and inside the tops, and this unusual brown coating inside the carb bores. Nasty!

[Sidecar Bob]

Yuk!! I have seen a very light golden tinge to some of the parts inside my carbs in the past but not often and not nearly like that.

You never said what you thought of my CX breather mod. Or did you forget that you used to be Twinstar on the Chopper Charles forum?

[mikenixon]

Sorry, didn't realize you were talking to me. Twinstar? Don't recall that.

[Sidecar Bob]

You were only active there for a short while a couple of years ago. I thought someone remembering your old screen name might make you grin

Anyway, at risk of becoming a pest, what do you think of my CX breather mod?

[mikenixon]

Bob, maybe it's old age or something, but you're going to have to remind me of what the mod was, pix, etc. Is it on this forum or the Chopper Charles one?

[Recycled Roadkill]

I'd like to see it too. Maybe a link could be posted here?

[Sidecar Bob]

The link is in post #35 of this thread

Hey Twinstar:
What do you think of this? http://cx500forum.com/index.php?/topic/ ... ntry134268

Do you think I would be better off to just connect the filter to the crankcase and plug the holes on the airbox?

Unfortunately, I wasn't able to take pics at the time. Just after I started to work on the breather mod I discovered that the rear Pro-Link suspension needed major work (including cutting one of the links out with an angle grinder) and winter was getting closer & closer so I had to scramble to keep from driving the 'Wing when there was the snow & salt on the roads.

BTW: I also added Zerks and cross drilled the suspension bearings & bushings so that the grease would get all the way through to the bolts so that I wouldn't have to go through all of that again http://cx500forum.com/index.php?/topic/ ... _p__114610 Now every year I loosen the nuts & bolts in the suspension and pump in fresh grease. If the grease comes out around the bolts I can tighten everything back up, knowing that nothing has seized and I will be able to disassemble it without cutting if I need to.

[Recycled Roadkill]

I'd checked out that link but was looking for the one with the pics. My mistake.

[mikenixon]

That zerk fitting trick is a good one. I used to do the same thing on V45 Sabres.

[Sidecar Bob]

I installed zerks in my GL500 in '01, posted about it on whichever predecessor of the Chopper Charles forum we were on back then and the idea caught on. When I tried taking it apart again 3 years later the bolts were all seized.

When I put Eccles together events conspired against me and I started about a month closer to snow & salt than I wanted to so I just cleaned & lubed the Pro-Link with the intention of doing it properly in a couple of years. When I did the bolts were seized and the ones that broke off were so hard they were impossible to drill out. I figured out that, with no lube between the bushings & the bolts, when the bushings eventually started to turn with the bearings and that work hardened the bolts. I took a long, hard look at the whole system and decided that the solution was to make sure that I could pump the grease into every part, including between the bushings & the bolts.

But anyways, back to something closer to your original topic: Do you think my breather mod is OK or should I be thinking about connecting the filter directly to the crankcase? I am in two minds about it: As it is now, if the filter clogs with goo or freezes up the crankcase pressure is still vented into the airbox. On the other hand, it would be nice to know I'm not spraying that garbage into the carbs.

Maybe the answer is to run the breather directly from the crankcase to some sort of vented catch can...