Removing the breather box?

[bassrad]

Hello all.
Just a question if the breather box cold be eliminated on GL1000 1977. Replacing the carbs and have nice access to it.
Could I just went the engine to the ground together with all other hoses or does the engine gets some back pressure from the box it self.

(Did the search, but couldn’t find the definite answer)

Cheers. And safe riding season everybody.

R.

[Whiskerfish]

The CV slides require vacuum to operate. As I understand it the design of the intake has a regulatory effect in their operation. That is why many of the experienced guru's consider even a change from the OEM filter to a reusable type to be taboo. Pistol Pete (RIP) once told me to take all my K&N's out and throw them in the trash because their "increased flow" would mess with the slide operation. It is generally accepted that you can do many Mods to the exhaust but leave the intake stock.

[bassrad]

Thanks Whiskerfish,

I am not planing to remove air filter, I was asking about the oil gathering container at the back of the engine that collects junk from crankcase. It is super hard to remove and clean with the cabs in.
I should have word it differently.
R.

[Whiskerfish]

Ahah! Yea I throw those away. Find a little pod filter that will fit the hose coming off the engine and put that on and eliminate all that if you like.

I have something like this I get at the local auto parts off the shelf.

61bUvHU3cNL._AC_SL1276_.jpg (93.07 KiB) Viewed 319 times

It is just there to prevent any oil from spraying out or crud from being ingested.

[Explorer]

When I initially installed one of those to the breather in order accommodate my single carb' conversion I was thinking exactly the wrong way around, that being, that the faster moving parts inside the motor would create a lower pressure, hence sucking air in. Turns out that it does blow air out and all it did was coat the top of the engine and other quite important local stuff with oil and god only knows what kind of crud was on the inside. So this time I'm just gonna run a hose to behind the rear fender, (if it ever gets that far,) or at least try to keep it off the tire.

[dontwantapickle]

Turns out that it does blow air out and all it did was coat the top of the engine and other quite important local stuff with oil and god only knows what kind of crud was on the inside. So this time I'm just gonna run a hose to behind the rear fender, (if it ever gets that far,) or at least try to keep it off the tire.

that "thing" is a catch tank for the crankcase breather.
it is designed to catch the oil and crud that blows out of the tube.
maybe it's a good idea to just keep it installed and keep the crud off of your bike.

[Briang]

The discharge tube from the right side of the air cleaner definitely needs to be air tight. This is to facilitate the gravity drainage to the collection container. If this tube is left open to the atmosphere by removing the collection container or putting a filter on the end totally defeats the ability of the thing to function properly.
I’m currently having a discussion with a fellow in Britain who declares the collection container is a North American system not used in British Goldwings. I would ask if one of our UK members can tell me is that is true. The only thing I can think of it is possibly similar to my CB900 which only has a plug in the end of the tube and you pull out the end of it and then the plug to drain the fluids.

[Whiskerfish]

It should have pulses in and out, not just pushing air out. If it is blowing then odds are high that exhaust gases are bypassing your rings. A healthy engine will see nearly zero oil output from one of those. Also if you are going to check for that make sure to rev the engine some. The last engine in my dressed 1000 had that issue and was consuming oil at about a quart every thousand miles. At idle it was fine but once up in the cruising rpm range the pulses out way over powered the pulses in. It was being pushed up into the air filter housing and then ingested through the carbs. Took me a while to figure out why my carbs were needing so much maintenance. So in this particular case changing the engine fixed my carbs
My current engine has maybe 20,000 miles since installed and zero oil has dripped out of the filter. Many of us run with just a filter and no issues.

The storage container is nothing more than a condensation tank. It may be black and nasty but 90% of it should be water.

[redglbx]

It’s been my experience that the breather/catch can is an important piece. On my 76 with the breather not connected it uses oil and a small amount more fuel. I believe it is something that should be serviced so that it is leak free and vacuum tight, should be serviced regularly on a rainy day with a few adult beverages.

My experience was that I forgot to reattach the hose to the air cleaner housing and my bike that normally used no oil used almost 3 quarts in 300mi to my surprise. Simply plugging it back in and it hasn’t used a drop in thousands of miles since. I pulled the can off when I got home and found the internal foam just disintegrating along with a bunch of bugs. The outlet/drain hose plug was also missing. It must have a plug.

My theory on why this makes a difference is that when plugged in & sealed up it provides a small amount of vacuum in the crankcase that’s keeps the rings from fluttering and allows the rings to seal better.

Guy’s that build drag and road race engines used to just run a drain tube from the crankcase to under the car but have found that getting some vacuum in the crankcase improves ring seal for better compression and oil control. Granted that being attached to the airbox only provides a small amount of vacuum but the results for me were noticeable.

Now as far as mods go on the intake vs the exhaust side, with the Dyno testing I have done anything done on the intake side will provide more performance to a point! There is more power on the intake side but with the stock 75-77 carbs it is very possible to create to much flow and make your throttle & performance soft until you’re into the very top parts of you rpm range, the bike will be slower. It’s a balance. Get the jetting right and there is an enjoyable ride in the end.

Exhaust side, there ain’t nothing but noise unless you start pushing 95-100hp at the rear wheel, then the stock pipes are at their limit. I will say that imho the stock header pipes are poor at best, no collector effect at all. A couple of aftermarket replacement header pipe makers offer a true collector setup that seems to work better than stock but I haven’t done a comparison between them on the dyno so it’s just opinion.

[pierce]

I have a 1200 in a 76 frame with 1200 carbs. The breather box wont fit because of a crossover bar so I run it without. I have had no issues - relatively speaking.

I did modify the breather box so it would fit, but there was no change in performance so I took it off again.

Keep in mind that I only get about 140 mpg. I think the 1200 generally gets better gas mileage than that, so not sure how that plays in. It also uses the black box ignition off the 1200.

Has anyone taken the box off to see what happens (on a stock 1000)?

[Rat]

Pierce ... nice to 'see' you again ... actually 140 mpg is quite good for a 1200 engine !!

Gord

[low-side]

Like most evaporative emissions devices, the engine will run fine without it if the modification is done properly. A filter is good as long as oil temps and blow-by are reasonable. If oil temps get high enough, oil vapor will escape the filter; too much blow-by will force oil vapor out at a greater rate than normal. Either one leaves you with a greasy engine. I'd use a road pipe, a piece of hose from the breather to the ground beside the center stand mount well offset from the rear tire. I'd put a vacuum cap on the hose barb at the air cleaner. You'll want to make sure that the road pipe isn't clogged periodically. I hope you find this useful.

[dontwantapickle]

can someone explain to me why pulling off the catch can and letting blowby oil puke all over the road
would be considered a good thing to do?

[Whiskerfish]

can someone explain to me why pulling off the catch can and letting blowby oil puke all over the road
would be considered a good thing to do?

Like I said before. Mine does not leak at all. I have the filter sitting on top of the engine near the fuel filter and nothing comes out of it. Been like that since I installed the engine in 16.

[bassrad]

Thanks all,

My breather box was not connected to the air filter housing for years and I didn't have any problems or any leaks.
I will test with the filter and see how it is going.

Safe riding all.

Radovan