78 XS750 with excessive oil burning and lower compression in center cyl.

[Pete in PA]

What is the PCV system on this bike? Honda liked having a little reservoir that filled from the airbox that had to be emptied periodically.

 

[jefferson997]

I always check on the center stand on level ground. The plugs showed the electrode was white, the insulator was tan and the outside ring was black.
No noticeable need for more throttle as both days were fairly calm. Mileage was consistent, but less than normal as I normally run no ethanol from a station near me. Makes 5 mpg difference on my ZRX and had to think a bit why I was getting worse mileage out of the XS.
The pcv system is a chamber on top of the crankcase that separates the oil from the vapors and it has a drain for the oil to return to the sump.

 

[Bonz]

Nice, I have a 2001 ZRX. 2-3 mpg difference on 10% ethanol vs 100% gas. My XS1100 didn't know the difference in ethanol vs non ethanol.

In any case, you are doing what you can and look forward to hearing how/when/if you find the answer.

 

[ZeeOSix]

I've been storing bikes and cars over the winter (usually 5 months) for decades, and have never had a problem. Same with my Craftsman lawn mower I've had for 40 years, and all were are using 10% ethanol fuel for the last 20+ years. I didn't even start use a fuel stabilizer until 5 years ago.

 

[Smoky14]

I always check on the center stand on level ground. The plugs showed the electrode was white, the insulator was tan and the outside ring was black.
No noticeable need for more throttle as both days were fairly calm. Mileage was consistent, but less than normal as I normally run no ethanol from a station near me. Makes 5 mpg difference on my ZRX and had to think a bit why I was getting worse mileage out of the XS.
The pcv system is a chamber on top of the crankcase that separates the oil from the vapors and it has a drain for the oil to return to the sump.

Back to my original post, the air/oil separator is inside the PCV housing. It is a plastic tube approx 6in long sitting vertically into the gear case. It was a factory fix for oil consumption and did NOT come on all XS models. I should have been more explicit in my post. Looks kinda funky but it works.
Smoky

 

[jefferson997]

Back to my original post, the air/oil separator is inside the PCV housing. It is a plastic tube approx 6in long sitting vertically into the gear case. It was a factory fix for oil consumption and did NOT come on all XS models. I should have been more explicit in my post. Looks kinda funky but it works.
Smoky

I have had that off before and really didn't pay too close attention. I'll have to pull the top off and check on what's inside. If there isn't one there that's going to be fun coming up with one now.

 

[jefferson997]

Back to my original post, the air/oil separator is inside the PCV housing. It is a plastic tube approx 6in long sitting vertically into the gear case. It was a factory fix for oil consumption and did NOT come on all XS models. I should have been more explicit in my post. Looks kinda funky but it works.
Smoky

I just pulled the housing apart and there was that plastic tube in there. Seems like it could be sealed better at the bottom so I may look at that to see what can be done.