Sight glass

[Conrad]

Boy you guys weren't kidding about the sight glasses on these things. When i bought the bike, it was full to the tippy-top. After changing the oil ( both plugs, proper amount of oil on refill), oil level smack in the middle. Cool beans, right? Check it periodically, still good. While i was doning the carbs, however, almost nothing, just a little at the bottom. Rode about 100 miles, back to the middle.
This thing doesn't leak oil, and no sign of burning any, so i know it should be fine, but i can't stand not being able to verify that there's oil in the engine

[cushman eagle]

The bike needs to be level right and left,as well as fore and aft,and it has to set long enough for the oil to drain down to be trusted.
Using those statements,my site glass has always been reliable for almost 13 years and 82,000 miles.
We have to make those points understood by our truck drivers, as neglecting them,can result in reading the dipsticks off by as much as +or- 2 gallons of oil

[Conrad]

That's the funny part, on the center stand, in the same spot in the garage i always park. Goofy thing.

[Nails]

I wish bikes came with a temperature-based oil-level sensor. I know it wouldn't work when running or not level, but it'd be nice to spot check before starting. I use the TPMS like that.

I had an RX-7 with a sensor like this in the sump. Surprised me the first time the alarm went off, when I had let the oil get really low and then took a curve the way the car was designed for. Took a while to sort what all the noise was about -- I initially thought the horn was blowing for some reason.

[ekap1200]

Boy you guys weren't kidding about the sight glasses on these things. When i bought the bike, it was full to the tippy-top. After changing the oil ( both plugs, proper amount of oil on refill), oil level smack in the middle. Cool beans, right? Check it periodically, still good. While i was doning the carbs, however, almost nothing, just a little at the bottom. Rode about 100 miles, back to the middle.
This thing doesn't leak oil, and no sign of burning any, so i know it should be fine, but i can't stand not being able to verify that there's oil in the engine

that part of the engine is pressure fed from that oil pipe. That is why there is a difference. If you see no leaks, pay it no mind and ride it until it needs an oil change. No leaks NO worry... its that simple.
Gene Kap

[Conrad]

Full to the top yesterday
Guess I'll just watch for puddles and smoke, and listen for engine noise. I sure miss dipsticks lol

[Nails]

I just changed my oil, now at about 4500mi. It was about 1/3 of the way up the sight glass as measured on the concrete floor of my new shop, which is "perfectly" level enough.

After a thorough draining (warm, filter and all), I filled it with about 4 more oz than the common recommendation of 3qts, 22oz (I spilled about 2oz of the last quart). After running the engine a little, that brought it to the middle of the sight glass.

My conclusions:

• my XII doesn't leak or burn oil;

• the 3qts, 22oz recommendation is fine, but all 4qts is fine too;

• the sight glass is a PITA to use*, and my plastic pitcher marked at 3qts, 22oz is a hella lot easier.

* The sight glass is hard to see even with a flashlight (which glares straight back at you) and even if the shifter rod didn't pass right through the middle of it (I dumped the floorboards for pegs -- the floorboard shifter was aligned differently).

Just get a cheap plastic pitcher at Goodwill, mark 3qts, 22oz, and ride enough to change your oil more often. I don't see any need to get more precise or precious about it.

[Vdriveboater]

I just changed the oil/filter and followed the 3 quarts 22oz recommendation that I read somewhere on this forum. The sight glass level is about 25% when the bike's on the center stand. I checked the owners manual and it states 4 quarts when replacing the filter (which I did). Was the manual information incorrect, and if so, who claims it's incorrect and on what information/research is this claim based?

[SgtSlag]

Page 6-6, in the manual, says 3.5 Liters, when changing the filter. Run a conversion on the Internet, and it comes to 3 quarts and 22.6 ounces. Everyone rounds down to 22 Oz.

These engines, if cared for, never burn oil. Most of us use 3q, 22 oz., and forget it until the next oil change. Cheers!

[GrandpaDenny]

IIRC it says 4 liters, which is about 3 qts 22oz. Don't believe the sight glass. If you're not blowing smoke, and not leaking, then don't worry about it until next oil change.

[Conrad]

I would add that since my original post, I've found if i put the bike on the centerstand and leave it overnight, it reads pretty consistently half to three quarters.

[Vdriveboater]

On page 15 of the Kawasaki owners manual it states that Engine Oil Capacity is 4 liters (4.2 quarts), but in the oil change/maintenance section it states 3.7 quarts when the filter is changed. Could it be that there is a half quart left in the engine that can't be drained out? Based on the low oil level showing on the sight glass with 3.7 quarts with filter change, I wonder if 4.2 quarts will bring the sight glass level somewhere between halfway and full? Looking at the oil change section of the manual for my ZRX1200R, it states 3.2 quarts "when the filter is removed" and 3.7 quarts "when engine is completely dry" (also stated 3.7 quarts capacity in the specs section), so there's a half quart difference right there. The real question is, what if any is the downside to adding oil so that it's at the 3/4 sight glass level? If there are no negatives (such as crank sloshing), having increased oil in the system is normally a good thing. After sitting on the center stand overnight with 3 quarts 22 ounces and a new filter, the sight glass level shows about 25%, keeping in mind that it appears that the stand leans the bike very slightly to the right.

[Vdriveboater]

I spoke to the service manager at my local dealer and he said that, as long as the level is between the minimum mark on the sight glass and the top of the sight glass (so that the level can be seen), that's where it needs to be. I added 10 ounces (total 4 quarts) and it brought the level up to 3/4, which I'm fine with.

[GrandpaDenny]

I spoke to the service manager at my local dealer and he said that, as long as the level is between the minimum mark on the sight glass and the top of the sight glass (so that the level can be seen), that's where it needs to be. I added 10 ounces (total 4 quarts) and it brought the level up to 3/4, which I'm fine with.

If you start hearing a bunch of noise, that's a sign that the oil is overfull. I've never experienced it, so I can't tell you exactly what it sounds like, but guys have described it on here. These bikes do seem to be sensitive to overfilling.

[Vdriveboater]

Thanks for the tip Denny. After a 25 mile ride in 85 degree ambient temps, I checked the temp at the back side of the cylinders (under the carbs) and it ranged from 200 to 220 and the radiator temp (checked from the front) ranged from 188 at the top to 174 at the bottom. Temp at the bottom of the block near the oil filter cover was 205. Do those seem to be normal?

[SgtSlag]

Round-about explanation...

I installed an Oil Cooler (oil radiator off of a CB900, using an after-market adapter made for CB750's) on my air-cooled CB750. I put an oil temp gauge in the adapter, sensing the oil temperature coming from the block, before it was sent to the Cooler, so it read the oil temperature as it came out of the engine! The oil temperature, with the Cooler bypassed, was running at 250 F, with an air temperature of 80 F; with the Cooler engaged, running two-up, at 55 MPH, in 92 F air temperatures, the oil ran at 210 F! Oil Cooling is not as effective as a water jacket around the engine...

Both of my cages run with a water temperature of 200-210 F. I don't know the Degree ratings on the XII's gauge, but anything around 200 F for the water seems normal, to me. If the oil temperature is between 180 F - 210 F, you have nothing to worry about.

Detergent oils do not suspend particulates until the oil reaches 180 F; by suspending the particulates, they get captured by the filter media. Below 180 F, the particulates tend to fall out of the oil, to the bottom of the engine and the sump. Hope this helps to put your mind at ease. Cheers!

[Riley1841]

thanks to all on this subject. I just changed my oil both plugs and filter. Added 3.2 qts. after sitting on center stand overnight 25% on sight gauge. Check it 5 minutes after 75 mile run it is almost 75% full. I will stay with 3.2 qts. This is a great forum I am learning something every time I spend time reading.

[GrandpaDenny]

thanks to all on this subject. I just changed my oil both plugs and filter. Added 3.2 qts. after sitting on center stand overnight 25% on sight gauge. Check it 5 minutes after 75 mile run it is almost 75% full. I will stay with 3.2 qts. This is a great forum I am learning something every time I spend time reading.

Where did you come up with 3.2 qts? Should be 3 quarts 22 oz. Glad you're learning something, that's why we're here, to learn and then to teach as we learn. I knew NOTHING about these bikes when I got here.

[Vdriveboater]

After filling with 4 quarts last week, I looked at the level yesterday and it was so close to the top of the window that I drained a few ounces, now it's showing 3/4 full and I feel better about it . . . .

[Van Voyager]

I wish bikes came with a temperature-based oil-level sensor.

Not realle related to your point, but the ZN1300 Voyager has a low oil level sensor and no oil pressure sensor. Seems goofy to me especially since, as I recall, later model naked Z1300's had both.