Get outa here! Not a hijack, I love this stuff. Interesting to see the similarities.
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Mailman’s XS2 a full on restoration
- Thread starter Mailman
- Start date
Get outa here! Not a hijack, I love this stuff. Interesting to see the similarities.
"The Basketcase" had the two tubes, angled down, with blackened Allens. I agree, Mm, the single, straight-out stubby looks better to me (with stainless Allens, polished shiny), and will make it easier for me to put a (cool-looking) breather on it. And, I'll check that oil tube for clearance! 
The single outlet breather housing was the last one Yamaha used and it came along around 1980. The outlet hole size was reduced so this one is probably the best at limiting the amount of oil and oil vapor that comes out .....
Too much oil or oil vapor being emitted from the breather was an issue on some of the early models, one that some owners complained about. Yamaha took various steps over the years to try and alleviate it. A big step, and one of the first, was to reduce the amount of oil used in the crankcase by about a half quart. This lowered the oil level in the cases by 10mm. Along with that, they completely capped off one of the breather outlets and only ran one outlet/hose. They ran this hose down into a hole in the left side cover and it acted sort of like an automatic chain oiler. This only lasted a couple years because pollution controls began to be implemented. You couldn't vent the oil vapors to atmosphere any more. So, they fed them into the airbox so the vapors would get recycled through the engine. They went back to using both hoses but rubber reducer plugs were fitted in the ends of the outlet pipes to greatly reduce the hole size .....
Finally, the redesigned single pipe housing was fitted. You can retrofit this to your earlier model if you like. If you are having excess oil misting problems, it may help.
Too much oil or oil vapor being emitted from the breather was an issue on some of the early models, one that some owners complained about. Yamaha took various steps over the years to try and alleviate it. A big step, and one of the first, was to reduce the amount of oil used in the crankcase by about a half quart. This lowered the oil level in the cases by 10mm. Along with that, they completely capped off one of the breather outlets and only ran one outlet/hose. They ran this hose down into a hole in the left side cover and it acted sort of like an automatic chain oiler. This only lasted a couple years because pollution controls began to be implemented. You couldn't vent the oil vapors to atmosphere any more. So, they fed them into the airbox so the vapors would get recycled through the engine. They went back to using both hoses but rubber reducer plugs were fitted in the ends of the outlet pipes to greatly reduce the hole size .....
Finally, the redesigned single pipe housing was fitted. You can retrofit this to your earlier model if you like. If you are having excess oil misting problems, it may help.
That’s very interesting 5T, to see the evolution of design. I have thought a lot about the venting system and what to do about it. When I got my XS2 , the two vent hoses ran down the spine of the frame between the carburetors and exited at the bottom of the frame just in front of the center stand. There was so much built up gunk from oil vapors, I really don’t care for that at all. So I started to think about what could be done about that. I had wanted to keep the bike pretty much true to the original design, so I had considered capping the hoses with a couple of breather filters and trying to hide them down low.
I had also considered soldering in a couple small tubes into the top of my air boxes, on the upper inside edge to try and recapture the oil fumes, similar to the way my air box does on my ‘77.
I also had a discussion with forum member Cra-Z1 about the way he handled this on his XS2. He has THE NICEST XS2 I’ve ever seen, and he used a couple of PVC valves that came from Mikes to cap off the hoses and he says it does a great job of capturing the vapors.
So, I haven’t decided exactly which way I want to go.
By the way, I was looking at the factory parts book that shows hex head bolts to mount the breather.
I had also considered soldering in a couple small tubes into the top of my air boxes, on the upper inside edge to try and recapture the oil fumes, similar to the way my air box does on my ‘77.
I also had a discussion with forum member Cra-Z1 about the way he handled this on his XS2. He has THE NICEST XS2 I’ve ever seen, and he used a couple of PVC valves that came from Mikes to cap off the hoses and he says it does a great job of capturing the vapors.
So, I haven’t decided exactly which way I want to go.
By the way, I was looking at the factory parts book that shows hex head bolts to mount the breather.
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One more note , if I decided to route the vent hoses to my air box, I am not going to run the stock paper filters so oil saturation wouldn’t be an issue, I am going to give UNI foam filters a try. Cleanable and reusable and half the cost of paper.
Bob, I was having a helluva time with oil all over my bike when I first put my XS2 motor back on the road. I basically just slid some threaded rod couplers into the tubes. They fit nice and snug and the reduced hole pretty much limited the vapors and took care of my problem.
I haven't noticed any problems and I got to keep my original look.
I haven't noticed any problems and I got to keep my original look.
Mailman
It will be interesting to see what you do and how it works for you.
It will be interesting to see what you do and how it works for you.
I started out with a little K&N filter on my breather hoses. I ran the two hoses to a "T" fitting, then down to one filter. I also removed the reducer plugs. The filter never actually dripped oil but it was soaked with it. It probably would have started dripping if I left it on there long enough. Next, I put the reducer plugs back in and changed to the power brake check valves. This seems to work much better. I don't notice any oil at all coming out of them. So, I would recommend check valves as opposed to just a filter, and adding some restriction to the breather outlet holes. Yamaha made them too big in my opinion.
I originally removed the reducer plugs based on info from the old 650Motorcycles.com web site. They had a page there that said to do so. Well, it may be fine on a racing motor but I think a street bike needs them. Luckily I saved them and was able to put them back in, lol.
I originally removed the reducer plugs based on info from the old 650Motorcycles.com web site. They had a page there that said to do so. Well, it may be fine on a racing motor but I think a street bike needs them. Luckily I saved them and was able to put them back in, lol.
When I installed the PVC valves i was told they create a slight negative crankcase pressure which limits the oil exhausting through the breather hoses rather than colecting the vapor as you stated. I dont have any oil dripping from the bottom of the PCV valves.
The valve is still available on MikesXS site but is hard to find with the search option. Search the part number and it will come up. Part 15-0677
The valve is still available on MikesXS site but is hard to find with the search option. Search the part number and it will come up. Part 15-0677
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This is how they handled crankcase ventilation on my old Triumph, I always thought it was a good design.
The vent hose ran from the top of the crankcase to the edge of the rear fender and followed the fender all the way to the end of the fender , where any oil drips wound up falling on the street, or blowing on the bumper of the car behind you!
The vent hose ran from the top of the crankcase to the edge of the rear fender and followed the fender all the way to the end of the fender , where any oil drips wound up falling on the street, or blowing on the bumper of the car behind you!
I did do some work yesterday, but didn’t post it. I was going to take a stab at mounting my cam seal housings up.
But seriously? They just weren’t shiny. That’ll never do, so.......
I spent a stupid amount of time on these, because I was too lazy to break out my buffer. This was hand sanding and polishing with felt bobs and a drill.
But come on, isn’t that totally worth it?
There’s still nothing in there, but they sure are pretty.
But seriously? They just weren’t shiny. That’ll never do, so.......
I spent a stupid amount of time on these, because I was too lazy to break out my buffer. This was hand sanding and polishing with felt bobs and a drill.
But come on, isn’t that totally worth it?
There’s still nothing in there, but they sure are pretty.
DanielBlack
XS650 Junkie
Robin would approve.
Right? I walk in his shadow. He was the master.
or blowing on the bumper of the car behind you!
...serves him right - he was following too close anyway.
Nice Bob!! The polish masters seal.....
Haha! Did you ever see Jay Leno riding his jet powered bike. I remember him saying if a car stopped to close behind him in traffic it would melt their bumper!
Nice Jim! I like it! Thanks
Feel free to save it and share it..Nice Jim! I like it! Thanks
Thanks, I already snagged it!
